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Visualforce Workbook |
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Version 6, Summer ’15 |
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@salesforcedocs |
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Last updated: July 1, 2015 |
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© Copyright 2000–2015 salesforce.com, inc. All rights reserved. Salesforce is a registered trademark of salesforce.com, inc., |
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as are other names and marks. Other marks appearing herein may be trademarks of their respective owners. |
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CONTENTS |
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Welcome to the Visualforce Workbook . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1 |
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Who this Workbook is For . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2 |
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Introduction to Visualforce . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3 |
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Creating and Listing Visualforce Pages . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3 |
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Enable Visualforce Development Mode . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3 |
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Create a Visualforce Page . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3 |
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Edit the Visualforce Page . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4 |
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Find all Visualforce Pages . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5 |
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Alternative Page Creation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5 |
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Summary . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5 |
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Adding Attributes and Using Auto-Suggest . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5 |
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Add Attributes Using Auto-Suggest . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6 |
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Add Additional Components . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7 |
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Add Nested Components . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8 |
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Summary . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8 |
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Understanding Simple Variables and Formulas . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8 |
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Global Variables . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9 |
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Basic Formulas . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9 |
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Conditionals . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10 |
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Summary . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10 |
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Using Standard Controllers . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11 |
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Find Identifiers of Records . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11 |
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Display Data from a Record . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 12 |
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Display Other Fields . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 13 |
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Display Fields from Related Records . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 13 |
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Summary . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 14 |
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Using Standard User Interface Components . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 14 |
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Display a Record or Related Lists . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 14 |
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Display Fields . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 15 |
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Display a Table . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 15 |
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Summary . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 16 |
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Updating Visualforce Pages with Ajax . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 16 |
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Identify a Region for Dynamic Updates . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 16 |
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Add Dynamic Re-Rendering . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 17 |
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Summary . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 17 |
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Overriding and Pointing to Pages . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 18 |
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Override the Standard Display for a Page . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 18 |
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Embed a Page on a Standard Layout . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 19 |
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Contents |
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Create a Button that Links to a Visualforce Page . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 19 |
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Create Hyperlinks to URLs or Other Visualforce Pages . . . . . . . . . . . . . . . . . . . . . . . . . 20 |
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Summary . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 20 |
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Inputting Data with Forms . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 21 |
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Create a Basic Form . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 21 |
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Show Field Labels . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 22 |
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Display Warning and Error Messages . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 22 |
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Summary . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 22 |
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Reusing Pages with Templates . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 23 |
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Create a Template . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 23 |
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Use a Template with Another Page . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 23 |
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Include One Visualforce Page within Another . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 24 |
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Summary . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 24 |
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Introduction to Apex . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 25 |
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Set Up Your Development Environment . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 25 |
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Install the Enhanced Warehouse Data Model . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 25 |
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Access the Mobile Browser Web App . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 26 |
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Download the Salesforce1 Mobile App . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 26 |
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Using the Developer Console . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 26 |
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Activating the Developer Console . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 26 |
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Using the Developer Console to Execute Apex Code . . . . . . . . . . . . . . . . . . . . . . . . . . 27 |
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Summary . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 29 |
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Creating and Instantiating Classes . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 29 |
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Creating an Apex Class Using the Developer Console . . . . . . . . . . . . . . . . . . . . . . . . 29 |
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Calling a Class Method . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 31 |
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Creating an Apex Class Using the Salesforce User Interface . . . . . . . . . . . . . . . . . . . . 32 |
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Summary . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 32 |
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Creating the WarehouseUtils Class . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 33 |
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Create the WarehouseUtils Apex Class . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 33 |
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Add a “Stub” findNearbyWarehouses Method . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 34 |
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Perform a Query and Return the Results . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 34 |
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Summary and Code Check . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 35 |
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Testing and Debugging the WarehouseUtils Class . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 36 |
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Create an Apex Test Class . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 36 |
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Add a Test Method and Setup Code . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 36 |
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Test the findNearbyWarehouses Method . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 38 |
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Run the Test and Review Test Results . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 39 |
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Find the Bug . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 41 |
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Write a Test for the Bug . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 41 |
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Fix the Bug . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 42 |
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Summary and Code Check . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 43 |
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Visualforce and Apex In Action . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 46 |
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Creating Location-Aware Visualforce Pages . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 46 |
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Create a Visualforce Page Linked to the WarehouseUtils Class . . . . . . . . . . . . . . . . . . . 46 |
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Add Static Resources to the Page . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 47 |
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Add a Place to Display the Map . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 48 |
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Add JavaScript to Query for Warehouses . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 48 |
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Add JavaScript to Build the Map . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 49 |
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Add JavaScript to Add Warehouse Markers to the Map . . . . . . . . . . . . . . . . . . . . . . . . 50 |
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Summary and Code Check . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 51 |
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Add the Nearby Warehouses Page to Salesforce1 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 54 |
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Create a Tab for the Page . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 55 |
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Add the Tab to Mobile Navigation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 55 |
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Try Out the App . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 55 |
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Summary . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 57 |
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Visualforce Pages with Apex Controllers . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 57 |
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Displaying Product Data in a Visualforce Page . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 57 |
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Using a Custom Apex Controller with a Visualforce Page . . . . . . . . . . . . . . . . . . . . . . 59 |
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Using Inner Classes in an Apex Controller . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 61 |
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Adding Action Methods to an Apex Controller . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 63 |
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Summary . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 65 |
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Conclusion and Where to Go From Here . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 66 |
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WELCOME TO THE VISUALFORCE WORKBOOK |
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Visualforce is a framework that allows developers to build sophisticated, custom user interfaces that can be hosted natively on the |
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Force.com platform. This workbook provides an introduction to many of the features in Visualforce, as well as a look at how you can use |
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Apex to add complex logic to your Visualforce pages. |
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You’ll learn how to build user interfaces that look like the standard user interface provided by Force.com, as well as how to build your |
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own user interfaces with all the control that HTML, CSS, and JavaScript provide. Along the way you’ll find out how to create components, |
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reusable pieces of Visualforce, as well as how to hook Visualforce into your applications. You’ll also learn about the Model–View–Controller |
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(MVC) foundations of Visualforce, and the fundamentals of Apex code. |
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Workbook Version |
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This workbook is current for Winter ’15, and was last revised on September 5, 2014. You should be able to complete all of the tutorials |
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using the Winter ’15 version of Force.com (API version 34.0) or later. |
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To download the latest version of this workbook, go to https://developer.salesforce.com/page/Force.com_workbook. |
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Before You Begin |
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These tutorials are designed to work with a Force.com Developer Edition organization, or DE org for short. DE orgs are environments |
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with all of the features and permissions that allow you to develop, package, test, and install apps. You can get your own DE org for free |
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at http://sforce.co/ZfioJ6, and you can use the techniques that you learn in this workbook in all Force.com environments that support |
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development. |
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It would also help to have a little context by learning a little about Force.com itself, which you can find in the first few tutorials of the |
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Force.com Workbook. |
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Finally, you’ll need a browser supported by Salesforce. Modern versions of Chrome, Firefox, Safari, and even Internet Explorer should do |
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the trick. |
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After You Finish |
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After you finish the workbook, you’ll be ready to explore a lot more Visualforce and Force.com development. Here’s a quick list of resources. |
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• Learn more about declarative (clicks, not code) Force.com development from the companion Force.com Workbook at |
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https://developer.salesforce.com/page/Force.com_workbook. |
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• Download the Visualforce Cheat Sheet at https://developer.salesforce.com/page/Cheat_Sheets. |
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• Get in-depth documentation for Visualforce in the Visualforce Developer’s Guide. |
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• Start learning the Apex programming language in depth with the Apex Workbook. |
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• Discover more Force.com and access articles, documentation, and code samples by visiting Developer Force at |
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http://developer.salesforce.com. |
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1 |
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Welcome to the Visualforce Workbook |
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Who this Workbook is For |
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Who this Workbook is For |
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This workbook is designed for two audiences. |
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• Experienced web developers, who have a solid understanding of HTML markup, and probably know how to write code in JavaScript |
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or a back-end language such as PHP, Ruby, C#, or Java. (If you know Apex, you’re ahead already.) |
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• Experienced Salesforce admins, who know Salesforce and have some basic HTML experience, but who might not have the |
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programming background of a web developer. |
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Both groups can learn a lot from this book. |
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This book is organized into three sections. |
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• Introduction to Visualforce teaches the basics of Visualforce markup. It’s great if you know HTML markup, but you don’t need to |
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be a programmer to follow every lesson. You’ll work with the built-in Salesforce objects such as Accounts and Contacts, and you’ll |
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stick to Visualforce and HTML markup—no programming. You’ll be surprised how far “pure Visualforce” takes you! |
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• Introduction to Apex provides a gentle introduction to Apex, the programming language of the Force.com platform, focused on |
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how you use it with Visualforce. If you’re a programmer, you’ll have no difficulty applying what you already know to quickly understand |
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how to write custom logic for your Force.com apps. Adventurous non-coders should also be able to follow along and understand |
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the basics. You might be inspired to learn a new skill! |
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• Visualforce and Apex In Action shows you how you can use the two together to create apps with custom user interfaces and |
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behavior. There’s no getting around it, there’s a lot of code to understand in this section. You’ll work with Visualforce, Apex, JavaScript, |
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the Google Maps API, and custom objects to create an app your users can access on the go in Salesforce1. That’s a lot of buzzwords |
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in one sentence, but we think you’ll be surprised and delighted at how easy it is to create a location-aware page for your mobile |
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users. |
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If you’re an experienced developer, you might be tempted to jump to the second section. We recommend you at least read the first |
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section, even if you skip the exercises, to understand the basics of the markup language. Also, there’s a lot you can do with Visualforce |
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by itself—code you don’t write is code you don’t have to maintain. |
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If you’re not a programmer, you might be intimidated by the code in this book. Don’t be. Learning Salesforce is an achievement, and if |
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you can do that, you can follow all of the exercises in this book. You don’t have to understand every line of code to learn useful techniques. |
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If you’re an admin just getting started with Force.com, you might find this book a little challenging. See the Force.com Platform Fundamentals |
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book for an introduction to the platform and point-and-click app development. |
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2 |
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INTRODUCTION TO VISUALFORCE |
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Visualforce is a component-based user interface framework for the Force.com platform. Visualforce allows you to build sophisticated |
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user interfaces by providing a view framework that includes a tag-based markup language similar to HTML, a library of reusable components |
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that can be extended, and an Apex-based controller model. Visualforce supports the Model-View-Controller (MVC) style of user interface |
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design, and is highly flexible. |
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In this section you’ll learn the basics of the Visualforce markup language. We’ll focus on the fundamentals, and work with the built-in |
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objects included with Salesforce—Account, Contact, and so on. |
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When you’re finished with this section, you will have done the following. |
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• Create new Visualforce pages and edit existing pages. |
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• Use two different Visualforce editors, and use the auto-suggest tools for adding Visualforce components and attributes. |
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• Design pages by combining simple built-in Visualforce components into larger page elements and structures. |
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• Load data from your organization and display it on the page, in detail and list views. |
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• Create forms that capture changes to data and save it to Salesforce. |
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• Add your custom pages to Salesforce where your users can access them, including overriding the built-in Salesforce create, edit, |
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and view pages. |
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• Perform page changes using Ajax to update parts of the page without reloading the whole page. |
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Creating and Listing Visualforce Pages |
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In this tutorial, you’ll learn how to create and edit your first Visualforce page. The page will be really simple, but this is the start, and we’ll |
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soon expand on it. Along the way you’ll familiarize yourself with the editor and automatic page creation. |
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Before you start, please create a free Force.com Developer Edition organization, as indicated earlier in the “Before you Begin” section. |
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Enable Visualforce Development Mode |
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Development mode embeds a Visualforce page editor in your browser that allows you to see code and preview the page at the same |
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time. Development mode also adds an Apex editor for editing controllers and extensions. |
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1. At the top of any Salesforce page, click the down arrow next to your name. From the menu under your name, select Setup or My |
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Settings—whichever one appears. |
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2. From the left panel, select one of the following: |
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• If you clicked Setup, select My Personal Information > Personal Information. |
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• If you clicked My Settings, select Personal > Advanced User Details. |
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3. Click Edit. |
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4. Select the Development Mode checkbox, then click Save. |
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Create a Visualforce Page |
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Now you are ready to create your first Visualforce page. |
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3 |
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|
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Introduction to Visualforce |
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Edit the Visualforce Page |
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1. |
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In your browser, add /apex/hello to the URL for your Salesforce instance. For example, if your Salesforce instance is |
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https://na1.salesforce.com, the new URL is https://na1.salesforce.com/apex/hello. You will see |
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the following error: |
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|
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2. Click the Create Page hello link to create the new page. You will see your new page with some default markup. |
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Note: If you don’t see the Page Editor below the page, just click the hello tab in the status bar. |
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That’s it! The page includes some default text, as well as an embedded page editor displaying the source code. This is the primary way |
|
you’ll be creating pages in this section of the workbook. |
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Edit the Visualforce Page |
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Now that you’ve created the Visualforce page, you need to customize it for your own use. You can edit and preview the changes in real |
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time. |
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1. You don’t want the heading of the page to say “Congratulations,” so change the contents of the <h1> tag to Hello World, remove |
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the comments, and the “This is your new page” text. The code now looks like this: |
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<apex:page> |
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<h1>Hello World</h1> |
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</apex:page> |
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2. Click the Save button at the top of the Page Editor. |
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The page reloads to reflect your changes. Note that Hello World appears in a large font. This is because of the <h1> tag—a standard |
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HTML tag. Visualforce pages are generally composed of two types of tags: tags that identify Visualforce components (such as |
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<apex:page>), and tags that are standard HTML. |
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4 |
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|
|
Introduction to Visualforce |
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|
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Find all Visualforce Pages |
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|
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Development mode, which you enabled in Step 1, makes development fast and easy. You can simply make changes, press Save, and |
|
immediately see the changes reflected. You can use a keyboard shortcut too—click CTRL+S to save at any time. You can also click the |
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editor minimize button to see the full page. |
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When you deploy the page in a production environment, or if you switch off development mode, the editor will no longer be available. |
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Find all Visualforce Pages |
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Now that you’ve created a Visualforce page, you’ll need to know where to find it. |
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1. From Setup, click Develop > Pages. |
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2. Scroll down to locate the page created in Step 2—hello. |
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This views your page, and even allows you to edit it. However, this editor is different from the one we’ve seen in the previous steps—it |
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also doesn’t let you immediately view the changes (unless you have the page open in a separate tab). |
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Alternative Page Creation |
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You can also create a new page from this listing, and then edit it just like you did in Step 2 by navigating to the correct URL—taking into |
|
account the name of the page you created. Try it! |
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1. From Setup, click Develop > Pages, then click New. |
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2. Create and label the page hello2. |
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3. Click Save. |
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4. Navigate to the new page using the URL as you did in Step 2: https://your-salesforce-instance/apex/hello2 |
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|
The Visualforce editor in Setup is good to know about, and a great way to see all your pages. However, the Development Mode editor |
|
we used in previous steps is more powerful, and lets you view your changes immediately. We’ll use it for the rest of this section of the |
|
workbook. |
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|
Summary |
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|
|
You now know how to enable development mode, and list and create Visualforce pages. In the next tutorial, you’ll learn a little about |
|
the page editor, and the basics of Visualforce components, which are the building blocks of any page. |
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Adding Attributes and Using Auto-Suggest |
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|
|
The page you created in Tutorial #1 shares a characteristic of every Visualforce page—it starts and ends with the <apex:page> tag. |
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<apex:page> is actually a Visualforce component—and one that must always be present. So all Visualforce pages will look similar |
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to this: |
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<apex:page> |
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Your Stuff Here |
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</apex:page> |
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Note the use of angle brackets, as well as how you indicate where a component starts and ends. The start is simply the component name |
|
in angle brackets: <apex:page>. The end is the component name prepended with a ‘/’ character in angle brackets: </apex:page>. |
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All Visualforce pages follow this same convention—requiring that the pages you create be “well-formed XML” (with a few exceptions). |
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A few components are self-closing—they have this form: <apex:detail /> (note the position of the /). Think of that as a start |
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and end tag wrapped up in one! |
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5 |
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|
|
Introduction to Visualforce |
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|
|
Add Attributes Using Auto-Suggest |
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You can generally modify the behavior and/or appearance of a component by adding attributes. These are name/value pairs that sit |
|
within the start tag. For example, here’s an attribute: sidebar="false". |
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|
Add Attributes Using Auto-Suggest |
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|
|
Let’s play some more with our first hello page. It turns out that the sidebar attribute is a valid attribute for the <apex:page> component. |
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1. Add sidebar="false" within the start tag of the <apex:page> component as follows: |
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<apex:page sidebar="false"> |
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2. Click Save. |
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Notice that the left hand area of your page has changed—the sidebar has been removed. In effect, the sidebar attribute modifies |
|
the behavior and appearance of the <apex:page> component. |
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|
|
3. Position your cursor just after the final quotation mark ("), and hit the space bar. A helpful list of attributes pop up that are valid for |
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|
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the <apex:page> component. Choose the showHeader attribute. |
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4. The attribute is automatically added to your page, and you now need to supply a value for the attribute. Add false. Your complete |
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first line should look like this: |
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<apex:page sidebar="false" showHeader="false"> |
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5. Click Save (remember, you can also press CTRL+S as a shortcut). |
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|
This time your page looks completely different. By setting the showHeader attribute to false, you’ve not only removed the top |
|
header, but all the default styling associated with the page. |
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|
|
Let’s put it back the way it was—having the top header is very useful during development. |
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|
|
6. Change the showHeader attribute’s value to true. |
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6 |
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|
|
Introduction to Visualforce |
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|
|
Add Additional Components |
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7. Click Save. |
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|
|
Add Additional Components |
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|
|
You’ve created a page, used the <apex:page> component, and changed its behavior. You’ll typically want to use additional |
|
components that supply a lot more functionality. |
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|
|
Visualforce comes with a several dozen built-in components, and you can install and build your own components to extend this set. In |
|
this lesson you’ll learn how to locate them, and use one. |
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|
|
1. Click the Component Reference link in the Page Editor. A help popup window displays with all available components. |
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|
|
2. Click <apex:pageBlock>. A description of what the component does, and what attributes you can add to change its behavior |
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|
|
displays in the Component Details tab. |
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|
3. Click the Usage tab to see an example of how to use the component. You’ll notice that the <apex:pageBlock> component |
|
is often used with the <apex:pageBlockSection> component. Click <apex:pageBlockSection> to learn more |
|
about that component. |
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|
In general, you’ll dip into the component reference whenever you need to. You’ll soon learn what the major components do—and |
|
while some of them take a large number of attributes, in practice you will only use a handful. |
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|
|
Now add both components to your page. We’re going to go a little faster here—see if you can do this without looking at the final |
|
code below. |
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|
4. Within the <apex:page> component, add an <apex:pageBlock> component with a title attribute set to A Block |
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|
|
Title. |
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|
5. Within the <apex:pageBlock> component, add an <apex:pageBlockSection> component, with its title attribute |
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|
|
set to A Section Title. |
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|
6. Within the <apex:pageBlockSection>, add some text, like I'm three components deep! |
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|
7. Click Save. Your final code will look something like this: |
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|
<apex:page sidebar="false"> |
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|
<apex:pageBlock title="A Block Title"> |
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|
<apex:pageBlockSection title="A Section Title"> |
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|
I'm three components deep! |
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|
</apex:pageBlockSection> |
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|
</apex:pageBlock> |
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|
</apex:page> |
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|
The final page will look something like this: |
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|
|
You can click the tiny disclosure triangle next to A Section Title to minimize that section of the block. |
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|
7 |
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|
|
Introduction to Visualforce |
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|
|
Add Nested Components |
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|
|
Add Nested Components |
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|
|
Adding additional components is easy. |
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|
|
1. Navigate to the end of the <apex:pageBlockSection> component, and add another <apex:pageBlockSection> |
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|
|
component with its own title. Both <apex:pageBlockSection> components must be contained within the same |
|
<apex:pageBlock> component. |
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|
|
2. Click Save and admire your handiwork. |
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|
<apex:page sidebar="false"> |
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|
|
<apex:pageBlock title="A Block Title"> |
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|
<apex:pageBlockSection title="A Section Title"> |
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|
I'm three components deep! |
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|
|
</apex:pageBlockSection> |
|
<apex:pageBlockSection title="A New Section"> |
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|
This is another section. |
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|
|
</apex:pageBlockSection> |
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|
</apex:pageBlock> |
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|
|
</apex:page> |
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|
|
Note the number of “nested” components. The start and the end tag for an <apex:pageBlockSection> are both within the |
|
start and end tag for the <apex:pageBlock> component. And your first <apex:pageBlockSection> ends before the next |
|
one starts (its end tag, </apex:pageBlockSection>, appears before the start of the new one, <apex:pageBlockSection>). |
|
All of the components on a Visualforce page tend to nest in this way—and the editor tells you when you’ve made a mistake (for example, |
|
if you forget an end tag). |
|
|
|
Summary |
|
|
|
In this tutorial you learned how to change the behavior and appearance of Visualforce components by adding attributes, how to use |
|
the auto-suggest feature of the editor, and how to use the Component Reference to look up additional components. You also learned |
|
that Visualforce components are often nested within each other. |
|
|
|
Learning More |
|
|
|
Here are additional Visualforce components that let you build pages that match the platform visual style: |
|
|
|
• <apex:pageBlockButtons> lets you provide a set of buttons that are styled like standard user interface buttons |
|
|
|
• The optional <apex:pageBlockSectionItem> represents a single piece of data in a <apex:pageBlockSection> |
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|
|
• <apex:tabPanel>, <apex:toolbar>, and <apex:panelGrid> provide other ways of grouping information on a page |
|
|
|
Understanding Simple Variables and Formulas |
|
|
|
The Visualforce pages you’ve created so far have been static. In general, Visualforce pages are dynamic—they can display data retrieved |
|
from the database, or data that changes depending on who is logged on and viewing the page. They can become dynamic through |
|
the use of variables and formulas. |
|
|
|
This tutorial introduces you to variables, formulas and the expression language syntax used in Visualforce. Variables typically contain |
|
information that you have retrieved from objects in the Force.com database, or which the platform has made available to you—for |
|
example, the name of the logged-in user. A number of built-in formulas are available to add functionality to your page—you’ll discover |
|
some basic formulas in this tutorial too. |
|
|
|
8 |
|
|
|
Introduction to Visualforce |
|
|
|
Global Variables |
|
|
|
Global Variables |
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|
|
Force.com retains information about the logged-in user in a variable called User. You can access fields of this User variable (and any |
|
others) by using a special expression language syntax: {! $<global variable>.<field name>} |
|
|
|
1. Modify your existing page to include the following line: {! $User.FirstName}. Remember that any content must lie within |
|
|
|
the <apex:page> component (between its open and closing tags). |
|
|
|
2. Click Save. |
|
|
|
Your Visualforce page looks something like this: |
|
|
|
<apex:page sidebar="false"> |
|
{! $User.FirstName} |
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|
|
</apex:page> |
|
|
|
In the future we’ll assume that you know to put any Visualforce markup within the <apex:page> tag. We’ll also assume that by now |
|
you’re comfortable enough to “Click Save” and view the result as well! |
|
|
|
The {! ... } tells Visualforce that whatever lies within the braces is dynamic and written in the expression language, and its value |
|
must be calculated and substituted at run time when someone views the page. Visualforce is case-insensitive, and spaces within the |
|
{! ... } syntax are also ignored. So this is just as effective: {!$USER.firstname}. |
|
|
|
Here’s how to show the first name and last name of the logged-in user: {! $User.FirstName} {! $User.LastName} |
|
|
|
Basic Formulas |
|
|
|
Visualforce lets you embed more than just variables in the expression language. It also supports formulas that let you manipulate values. |
|
The & character is the formula language operator that concatenates strings. |
|
|
|
1. Add this to your Visualforce page: {! $User.firstname & ' ' & $User.lastname} |
|
|
|
This tells Visualforce to retrieve the firstname and lastname fields from the global User object, and to concatenate them with a space |
|
character. The output will be something like: Joe Bloggs. |
|
|
|
In general, formulas are slightly more advanced and have a simple syntax that includes the function name, a set of parentheses, and |
|
an optional set of parameters. |
|
|
|
2. Add this to your Visualforce page: |
|
|
|
<p> Today's Date is {! TODAY()} </p> |
|
<p> Next week it will be {! TODAY() + 7} </p> |
|
|
|
You’ll see something like this in the output: |
|
|
|
Today's Date is Wed Feb 08 00:00:00 GMT 2012 |
|
Next week it will be Wed Feb 15 00:00:00 GMT 2012 |
|
|
|
The <p> tags are standard HTML for creating paragraphs. In other words, we wanted both sentences to be in individual paragraphs, |
|
not all on one line. The TODAY() function returns the current date as a date data type. Note how the time values are all set to 0. |
|
Also note the + operator on the date. The expression language assumes you want to add days, so it added 7 days to the date. |
|
|
|
3. You can use functions as parameters in other functions, and also have functions that take multiple parameters too. Add this: |
|
|
|
<p>The year today is {! YEAR(TODAY())}</p> |
|
<p>Tomorrow will be day number {! DAY(TODAY() + 1)}</p> |
|
<p>Let's find a maximum: {! MAX(1,2,3,4,5,6,5,4,3,2,1)} </p> |
|
|
|
9 |
|
|
|
Introduction to Visualforce |
|
|
|
Conditionals |
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|
|
<p>The square root of 49 is {! SQRT(49)}</p> |
|
<p>Is it true? {! CONTAINS('salesforce.com', 'force.com')}</p> |
|
|
|
The output will look something like this: |
|
|
|
The year today is 2012 |
|
Tomorrow will be day number 9 |
|
Let's find a maximum: 6 |
|
The square root of 49 is 7.0 |
|
Is it true? true |
|
|
|
The CONTAINS() function returns a boolean value: something that is either true or false. It compares two arguments of text and |
|
returns true if the first argument contains the second argument. If not, it returns false. In this case, the string “force.com” is contained |
|
within the string “salesforce.com”, so it returns true. |
|
|
|
Conditionals |
|
|
|
Sometimes you want to display something dynamically, based on the value of an expression. For example, if an invoice has no line items, |
|
you might want to display the word “none” instead of an empty list, or if some item has expired, you might want to display “late” instead |
|
of showing the due date. |
|
|
|
You can do this in Visualforce by using a conditional formula expression, such as IF(). The IF() expression takes three arguments: |
|
|
|
• The first is a boolean: something that is either true or false. You’ve seen an example of that in the CONTAINS() function. |
|
|
|
• The second argument is something that will be returned if the boolean is true. |
|
|
|
• The third argument is something that will be returned if the boolean is false. |
|
|
|
Insert the following and try to predict what will be displayed if you save the page: |
|
|
|
{! IF ( CONTAINS('salesforce.com','force.com'), 'Yep', 'Nah') } |
|
{! IF ( DAY(TODAY()) > 14, 'After the 14th', 'On or before the 14th') } |
|
|
|
You’ll see something like this: |
|
|
|
Yep |
|
On or before the 14th |
|
|
|
Of course, this all depends on when you run the code. After the 14th in a month, it looks different. |
|
|
|
Summary |
|
|
|
Visualforce lets you embed operations that evaluate at runtime using a special expression language syntax: {! expression}. Global |
|
variables are accessed using the $VariableName syntax. The expression language lets you manipulate strings, numbers, text, and |
|
dates, as well as conditionally execute operations. |
|
|
|
Learning More |
|
|
|
• The Formulas Cheat Sheet provides a concise guide to the many formulas you can use. |
|
|
|
• The Visualforce Developer’s Guide has a lot more detail on formulas. |
|
|
|
10 |
|
|
|
Introduction to Visualforce |
|
|
|
Using Standard Controllers |
|
|
|
Using Standard Controllers |
|
|
|
Visualforce’s Model-View-Controller (MVC) design pattern makes it easy to separate the view and its styling from the underlying database |
|
and logic. In MVC, the view (the Visualforce page) interacts with a controller. In our case, the controller is usually an Apex class, which |
|
exposes some functionality to the page. For example, the controller can contain the logic to be executed when a button is clicked. A |
|
controller also typically interacts with the model (the database)—making available data that the view might want to display. |
|
|
|
Most Force.com objects have default standard controllers that can be used to interact with the data associated with the object, so in |
|
many cases you don’t need to write the code for the controller yourself. You can extend the standard controllers to add new functionality, |
|
or create custom controllers from scratch. In this tutorial, you’ll learn about the standard controllers. |
|
|
|
Find Identifiers of Records |
|
|
|
When your Visualforce pages interact with other pages in your application, you can automatically pass in the record’s identifier, and your |
|
Visualforce page can then display that data. Right now your pages are stand-alone, so for your page to display data from a record in the |
|
database, it needs to know the record’s identifier. |
|
|
|
Your Developer Edition environment has a number of objects that store data, available out of the box. |
|
|
|
1. For example, switch to the Sales application by choosing Sales from the drop down. |
|
|
|
2. Now select the Accounts tab. Ensure the pick list shows All Accounts and click Go to view all the account records. |
|
|
|
3. Click Burlington Textiles (or any other record) to view the details. Your screen displays all the details for that account: |
|
|
|
11 |
|
|
|
Introduction to Visualforce |
|
|
|
Display Data from a Record |
|
|
|
Notice that your URL has changed—it now looks something like this: https://<your salesforce |
|
instance>.salesforce.com/0018000000MDfn1 |
|
|
|
The identifier is that series of digits at the end, in this case, 0018000000MDfn1. The identifier, or ID as it’s often written, is unique across |
|
all records in your database. If you know the ID for any record, and have permission, you can often construct a URL to view it by replacing |
|
0018000000MDfn1 with the record’s identifier. |
|
|
|
When you visited https://<salesforce instance>.salesforce.com/0018000000MDfn1, Force.com automatically |
|
retrieved the record with identifier 0018000000MDfn1 from the database, and automatically constructed a user interface for it. In the |
|
other lessons in this tutorial, you’re going to take away some of the automation, and create your own user interface. |
|
|
|
Display Data from a Record |
|
|
|
Create a new Visualforce page, accountDisplay, with the following content: |
|
|
|
<apex:page standardController="Account"> |
|
<p>Hello {! $User.FirstName}!</p> |
|
<p>You are viewing the {! account.name} account.</p> |
|
|
|
</apex:page> |
|
|
|
You’ll recognize the {! } expression syntax from the previous tutorial, and that $User.FirstName refers to the First Name field |
|
of the User global variable. There are a few new things though: |
|
|
|
1. The standardController="Account" attribute tells Visualforce to use an automatically-generated controller for the |
|
|
|
Account object, and to provide access to the controller in the Visualforce page. |
|
|
|
2. The {! account.name} expression retrieves the value of the account variable’s name field. The account variable is automatically |
|
|
|
made available by the standard controller (it’s named after the standard controller’s name). |
|
|
|
Controllers generally have logic that handles button clicks and interacts with the database. By using the standardController |
|
attribute, your Visualforce page has access to a rich controller that is automatically generated for you. |
|
|
|
The standard controller for the Account object determines when an identifier is being used in the page, and if it is, queries the database |
|
and retrieves the record associated with that identifier. It then assigns that record to the account variable so that you can do as you |
|
please with the data in your Visualforce page. |
|
|
|
12 |
|
|
|
Introduction to Visualforce |
|
|
|
Display Other Fields |
|
|
|
When you click Save, you will see your first name and an empty account name. This is because you haven’t told the Visualforce page |
|
which account record to display. Go to your URL and modify it so that you include the ID from Step 1. So instead of something like: |
|
|
|
https://na3.salesforce.com/apex/accountDisplay |
|
|
|
change it to something like: |
|
|
|
https://na3.salesforce.com/apex/accountDisplay?id=0018000000MDfn1 |
|
|
|
In your case, change the identifier 0018000000MDfn1 to whatever you found in Step 1. You might need to change “na3” as well, to |
|
whatever your salesforce instance currently is. |
|
|
|
Now when you save your work, the account name displays: |
|
|
|
Display Other Fields |
|
|
|
Your accountDisplay page only displays the name field of the Account object. To find other fields to display for the object, from |
|
Setup, click Customize > Accounts > Fields. Click any field, such as Ticker Symbol. The Field Name field provides the name that you |
|
can use in your own Visualforce pages. For example, for this particular field, the name is TickerSymbol. |
|
|
|
Modify accountDisplay to include this field by adding the following paragraph after the existing one: |
|
|
|
<p>Here's the Ticker Symbol field: {! account.TickerSymbol}</p> |
|
|
|
Display Fields from Related Records |
|
|
|
You can also display data from related records. For example, while viewing the object details for Account, you might have noticed that |
|
the Account object has a field called Account Owner, and that its type is Lookup(User). In other words, this field has a relationship to a |
|
User record. By clicking the Account Owner field label link, you’ll discover its Field Name is Owner. |
|
|
|
The Owner relationship represents a User. And, if you click Customize > Users > Fields, you’ll find that User has a Name field. Let’s use |
|
this information to display it. |
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1. Modify accountDisplay to include this field by adding the following paragraph after the existing one: |
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<p>Here's the owner of this account: {! account.Owner.Name}</p> |
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The “dot notation” (account.Owner.Name) indicates that you want to traverse the relationship between the records. You know |
|
that account.Owner indicates the Owner field of the account record. The extra name at the end indicates that the owner field isn’t |
|
a simple field representing a String, but a relationship to another record (it’s a Lookup(User)), and that you’d like to get the record |
|
represented by the value of the Owner field (it’s a User record), and display the Name field on that record. |
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|
|
Tip: If you’ve created your own custom objects (instead of using objects like Account) and want to know how to reference a field, |
|
you have to follow a slightly different procedure. From Setup, click Create > Objects, select your object, and then the field. The |
|
API Name now indicates the name of the field that you must use in your Visualforce pages. For example, if your field was called |
|
Foo, its API Name is Foo__c, and you’d reference it with that name—something like: {! myobject__c.foo__c}. |
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13 |
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|
|
Introduction to Visualforce |
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|
|
Summary |
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|
Summary |
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|
Standard controllers provide basic, out-of-the-box, controller functionality, including automatic record retrieval. This tutorial showed |
|
how to locate the identifier for a record and use the standard controller to display the record’s data. The standard controller also contains |
|
functionality to save or update a record, which you’ll see later. |
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|
|
Learning More |
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|
|
Visualforce also supports standard list controllers, which allow you to create Visualforce pages that can display or act on a set of records, |
|
with pagination. |
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|
|
Using Standard User Interface Components |
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|
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In Adding Attributes and Using Auto-Suggest you learned about the <apex:pageBlockSection> component, and in the |
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previous tutorial you learned how to show some data from an Account record using the expression language. In this tutorial you’ll |
|
discover additional Visualforce components that produce output that looks and feels like the automatically-generated user interfaces. |
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|
|
Display a Record or Related Lists |
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|
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Creating a list of records is as easy as typing up a single component. |
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|
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1. Modify your accountDisplay Visualforce page to look like this: |
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<apex:page standardController="Account"> |
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<apex:detail/> |
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</apex:page> |
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If you access your page with a valid account ID passed in as a parameter, as demonstrated in the previous tutorial (it will look |
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something like this: https://na3.salesforce.com/apex/AccountDisplay?id=0018000000MDfn1), then |
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you’ll see a lot of output. |
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|
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2. The <apex:detail/> component displays the standard view page for a record. It shows related lists as well, such as contacts. |
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You can switch these off by adding the relatedList="false" attribute. Try adding it, click Save, and spot the difference. |
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3. You can show only a particular related list; such as the list of case records that are related to the account record you are viewing. |
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Add the following tag: |
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<apex:relatedList list="Cases" /> |
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Although these tags are very simple, they’re doing a lot of work for you—and relying on that standard controller to go and retrieve the |
|
data. Sometimes, however, you want more control over page layout. |
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14 |
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|
|
Introduction to Visualforce |
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|
|
Display Fields |
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|
|
Display Fields |
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|
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If you want to selectively determine a record’s fields for display, use the <apex:outputField> component. This component, |
|
when embedded in the <apex:pageBlock> component, displays not only the value of the field, but also the field’s label. |
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|
|
1. |
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|
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Insert the following into your page to see it in action: |
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<apex:pageBlock title="Custom Output"> |
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<apex:pageBlockSection title="Custom Section Title"> |
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<apex:outputField value="{!account.Name}"/> |
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<apex:outputField value="{!account.Owner.Name}"/> |
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</apex:pageBlockSection> |
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</apex:pageBlock> |
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Here, account.Name specifies the current account record’s name field, whereas account.Owner.Name looks at the owner |
|
field of the account record, and then retrieves that record’s name field. |
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Display a Table |
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|
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In the previous lessons, you displayed individual fields and a complete record. Sometimes however, you need to display a set of fields |
|
across a number of records—for example, the list of contacts associated with the account. In this step you will list the contacts of an |
|
account record by iterating over the list and displaying each one individually. It may seem complex initially because there are multiple |
|
tags that nest within each other, but you will find it second nature in no time. Don’t forget you can always click the Component |
|
Reference link to learn more about each. |
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1. First start by adding an <apex:pageBlock> component: |
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<apex:pageBlock title="My Account Contacts"> |
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</apex:pageBlock> |
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2. You can save and view the result if you like. Now within this component, insert another one, the <apex:pageBlockTable> |
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|
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component: |
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<apex:pageBlockTable value="{! account.contacts}" var="item"> |
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</apex:pageBlockTable> |
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You can think of this component as doing the following: it takes a look at its value attribute, and retrieves the list of records that |
|
it finds there. In this case, it retrieves the contacts field that represents the list of Contact records associated with the current |
|
Account record. Then, for each individual Contact record, it assigns it to a variable called item. It does this repeatedly until it reaches |
|
the end of the list. The key lies in the body of the component. This will be output at each iteration—effectively allowing you to |
|
produce something for each individual record. |
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3. |
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|
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Ideally, you want to insert something inside of the <apex:pageBlockTable> component that does something with the |
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current item. Try adding this: |
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<apex:column value="{! item.name}"/> |
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15 |
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|
|
Introduction to Visualforce |
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|
|
Summary |
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|
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The <apex:column> component creates a new column within the table. It adds a table header based on the name of the field, |
|
and also outputs the values for that field in the rows of the table, one row per record. In this case, you have specified {! |
|
item.name}, which will show the name field for each of the Account’s Contacts. |
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|
|
Here’s what your final code looks like: |
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<apex:pageBlock title="My Account Contacts"> |
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<apex:pageBlockTable value="{! account.contacts}" var="item"> |
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<apex:column value="{! item.name}"/> |
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</apex:pageBlockTable> |
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</apex:pageBlock> |
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|
Contact records also have a field called phone. Try adding a column to display the phone numbers. Of course, if you don’t have any |
|
contacts associated with the account that you’re viewing, or if you haven’t supplied an account ID, then it won’t display anything. |
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|
|
Summary |
|
|
|
The <apex:detail> and <apex:relatedList> components make it tremendously easy to display records and related lists |
|
by utilizing the standard controller to automatically retrieve the record’s data. The <apex:pageBlockTable> component provides |
|
a way to iterate over a list of records, producing output for each record in the list. |
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|
|
Learning More |
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|
|
• Use <apex:facet> to customize the caption, headers and footers of a table. |
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|
|
• The <apex:enhancedList> and <apex:listViews> components provide a way to embed a standard list view of an |
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|
|
object’s records. |
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|
|
Updating Visualforce Pages with Ajax |
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|
|
Visualforce lets you use Ajax effects, such as partial page updates, without requiring you to implement any complex JavaScript logic. |
|
The key element is identifying what needs to be dynamically updated, and then using the rerender attribute to dynamically update |
|
that region of the page. |
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|
|
Identify a Region for Dynamic Updates |
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|
|
A common technique when using Ajax in Visualforce is to group and identify the region to be dynamically updated. The |
|
<apex:outputPanel> component is often used for this, together with an id attribute for identifying the region. |
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|
|
1. Create a Visualforce page called Dynamic, using the following body: |
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|
<apex:page standardController="Account"> |
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|
|
<apex:pageBlock title="{!account.name}"> |
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|
|
<apex:outputPanel id="contactDetails"> |
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|
|
16 |
|
|
|
Introduction to Visualforce |
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|
|
Add Dynamic Re-Rendering |
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|
|
<apex:detail subject="{!$CurrentPage.parameters.cid}" |
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|
|
relatedList="false" title="false"/> |
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|
|
</apex:outputPanel> |
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|
|
</apex:pageBlock> |
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|
|
</apex:page> |
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|
|
2. Ensure that your Visualforce page is called with an identifier for a valid account. |
|
|
|
Your Visualforce page won’t show much at all except for the account name. Note that the <apex:outputPanel> has been given |
|
an identifier named contactDetails. Also note that the <apex:detail> component has a subject attribute specified. |
|
This attribute is expected to be the identifier of the record whose details you want to display. The expression |
|
{! $CurrentPage.parameters.cid} returns the cid parameter passed to the page. Since you’re not yet passing in such |
|
a parameter, nothing is rendered. |
|
|
|
Add Dynamic Re-Rendering |
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|
|
Now you need to add elements to the page that set the page parameter and dynamically render the region you’ve named detail: |
|
|
|
1. Modify your page by adding a new page block beneath your current one: |
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|
|
<apex:pageBlock title="Contacts"> |
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|
|
<apex:form> |
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|
|
<apex:dataList value="{! account.Contacts}" var="contact"> |
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|
|
{! contact.Name} |
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|
|
</apex:dataList> |
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|
|
</apex:form> |
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|
|
</apex:pageBlock> |
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|
|
This iterates over the list of contacts associated with the account, creating a list that has the name of each contact. |
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|
|
2. Click Save. |
|
|
|
If you access your page, you’ll see the list of contacts. Now you need to make each contact name clickable. |
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|
|
3. Modify the {! contact.Name} expression by wrapping it in an <apex:commandLink> component: |
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|
|
<apex:commandLink rerender="contactDetails"> |
|
|
|
{! contact.Name} |
|
<apex:param name="cid" value="{! contact.id}"/> |
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|
|
</apex:commandLink> |
|
|
|
There are two important things about this component. First, it uses a rerender="contactDetails" attribute to reference the |
|
output panel you created earlier. This tells Visualforce to do a partial page update of that region when the name of the contact is clicked. |
|
Second, it uses the <apex:param> component to pass a parameter, in this case the id of the contact. |
|
|
|
If you click any of the contacts, the page dynamically updates that contact, displaying its details, without refreshing the entire page. |
|
|
|
Summary |
|
|
|
Visualforce provides native support for Ajax partial page updates. The key is to identify a region, and then use the rerender attribute |
|
to ensure that the region is dynamically updated. |
|
|
|
17 |
|
|
|
Introduction to Visualforce |
|
|
|
Overriding and Pointing to Pages |
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|
|
Learning More |
|
|
|
There’s a lot more to the Ajax and JavaScript support: |
|
|
|
• <apex:actionStatus> lets you display the status of an Ajax request—displaying different values depending on whether it’s |
|
|
|
in-progress or completed. |
|
|
|
• <apex:actionSupport> lets you specify the user behavior that triggers an Ajax action for a component. Instead of waiting |
|
for an <apex:commandLink> component to be clicked, for example, the Ajax action can be triggered by a simple mouse |
|
rollover of a label. |
|
|
|
• <apex:actionPoller> specifies a timer that sends an Ajax update request to Force.com according to a time interval that you |
|
|
|
specify. |
|
|
|
• <apex:actionFunction> provides support for invoking controller action methods directly from JavaScript code using an |
|
|
|
Ajax request. |
|
|
|
• <apex:actionRegion> demarcates the components processed by Force.com when generating an Ajax request. |
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|
|
Overriding and Pointing to Pages |
|
|
|
Using Visualforce, you can override pretty much any aspect of the user interface, such as buttons, tabs, or links. |
|
|
|
In this tutorial, you’ll explore how to use Visualforce pages that you’ve created to replace standard Salesforce behavior. |
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|
|
Override the Standard Display for a Page |
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|
|
The Visualforce page you created in Using Standard Controllers can function as a replacement to the standard detail page for an account. |
|
You can modify the standard user interface generated by the platform to ensure that your page gets shown instead of the standard |
|
page. |
|
|
|
1. From Setup, click Customize > Accounts > Buttons, Links, and Actions. |
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|
|
2. Click Edit next to the View item. |
|
|
|
3. For Override With, select Visualforce Page. |
|
|
|
4. From the Visualforce Page drop-down list, select accountDisplay. |
|
|
|
5. Click Save. |
|
|
|
To see this in action, select the Accounts tab and then choose an account. Your page displays instead of the default. You’ve successfully |
|
configured the platform to automatically pass in that ID parameter to your page. |
|
|
|
18 |
|
|
|
Introduction to Visualforce |
|
|
|
Embed a Page on a Standard Layout |
|
|
|
6. Follow the same procedure to reverse the override, so you can view the default page on the next lesson. |
|
|
|
Embed a Page on a Standard Layout |
|
|
|
Another way to get your page displayed is to embed it within a standard layout for another page. For example, imagine your |
|
accountDisplay showed an interesting analysis of the account data, and you wanted to embed it within the standard account |
|
detail view. |
|
|
|
1. From Setup, click Customize > Accounts > Page Layouts. |
|
|
|
2. Click Edit next to Account Layout. |
|
|
|
3. Select Visualforce Pages in the left column of the user interface elements palette. |
|
|
|
4. You’ll notice your page appears here (because it uses the Accounts standard controller). |
|
|
|
5. Select accountDisplay, and drag it to the Account Information panel. |
|
|
|
6. Click Save. |
|
|
|
7. To see this in action, select the Accounts tab and then choose an account. You’ll notice the standard display of data, with your |
|
|
|
Visualforce page embedded within it! Your embedded page ideally needs to accommodate the inline display, so it might look a little |
|
plain right now, but notice how the embedded page automatically shows data of the same record—it’s also being passed the ID |
|
parameter. |
|
|
|
Create a Button that Links to a Visualforce Page |
|
|
|
Pages like the standard account detail page have buttons, such as Edit and Delete. You can add a new button here that links to your |
|
page. |
|
|
|
1. From Setup, click Customize > Accounts > Buttons, Links, and Actions. |
|
|
|
2. Click New Button or Link. |
|
|
|
3. Enter MyButton for the Label. |
|
|
|
4. Enter My_Button for the Name. |
|
|
|
5. For the Display Type, select Detail Page Button. |
|
|
|
6. Select Visualforce Page in the Content Source picklist. |
|
|
|
7. |
|
|
|
In the Content picklist that appears, select your accountDisplay page. |
|
|
|
8. Click Save. |
|
|
|
19 |
|
|
|
Introduction to Visualforce |
|
|
|
Create Hyperlinks to URLs or Other Visualforce Pages |
|
|
|
9. Now that you have your button, you need to add it to a page layout. Repeat the process from Embed a Page on a Standard Layout |
|
|
|
but, instead of selecting a Visualforce page, add a button, and select MyButton. |
|
|
|
Note: Depending on your browser settings, you might get a privacy warning—allow your browser to load pages from the |
|
Visualforce domain to avoid these warnings. |
|
|
|
You can use a similar procedure to create a link instead of a button, and you can add many buttons and links to standard and custom |
|
pages to create just the right navigation and user interface for your app. |
|
|
|
Create Hyperlinks to URLs or Other Visualforce Pages |
|
|
|
You might want to point from one Visualforce page to another, or to an external URL. |
|
|
|
1. Modify your Visualforce page to include the <apex:outputlink> component to produce a link: |
|
|
|
<apex:outputLink value="http://developer.salesforce.com/">Click me!</apex:outputLink> |
|
|
|
2. To reference a page, use the expression {! $Page.pagename} to determine its URL. |
|
|
|
3. You can then include a link as follows: |
|
|
|
<apex:outputLink value="{! $Page.AccountDisplay}">I am me!</apex:outputLink> |
|
|
|
You can think of $Page as a global object that has a field for every page you’ve created. |
|
|
|
Summary |
|
|
|
Once you’ve created your Visualforce page, there are many ways to view it. You can just enter its URL, but you can also make it replace |
|
one of the automatically-generated pages, embed it within an existing page layout, or create buttons and hyperlinks that link to it. |
|
|
|
Learning More |
|
|
|
• Visualforce pages can also be viewed on public-facing web sites by using Force.com Sites. See the Force.com Workbook for an |
|
|
|
example. |
|
|
|
20 |
|
|
|
Introduction to Visualforce |
|
|
|
Inputting Data with Forms |
|
|
|
• Sometimes you want to embed links to default actions, such as creating a new Account. Use the <apex:outputLink> |
|
|
|
component together with URLFOR() and the $Action global variable. For example: |
|
|
|
<apex:outputLink value="{! URLFOR($Action.Account.new)}">Create</apex:outputLink> |
|
|
|
Inputting Data with Forms |
|
|
|
In this tutorial you learn how to create input screens using the standard controller, which provides record save and update functionality |
|
out of the box. This introduces you to the major input capabilities and their container—the <apex:form> component. Creating and |
|
Using Custom Controllers extends this and shows how to build forms that interact with your own controllers. |
|
|
|
Create a Basic Form |
|
|
|
The key to any data input is using a form. In this lesson you’ll create the most basic form. |
|
|
|
1. Create a new Visualforce page called MyForm, which uses a standard controller for the Account object. |
|
|
|
<apex:page standardController="Account"> |
|
</apex:page> |
|
|
|
2. |
|
|
|
Insert an <apex:form> component, into which all your input fields will be placed: |
|
|
|
<apex:form> |
|
</apex:form> |
|
|
|
3. Within the form, add an input field for the name field of an account, as well as command button that saves the form when clicked: |
|
|
|
<apex:inputField value="{! account.name}"/> |
|
<apex:commandButton action="{! save}" value="Save!"/> |
|
|
|
This form, although very basic, contains all the essential elements: a form, an input field, and a button that processes the form: |
|
|
|
In this case, you use a <apex:commandButton> which produces a button. Note that the action element is bound to {! save}. |
|
This expression language syntax looks similar to the syntax you used to specify a field in a record. However, in this context, it references |
|
a method—a piece of code named save. Every standard controller automatically supplies a save() method—as well as update() |
|
and other methods—so in this case, the save() method on the standard controller is invoked when the button is clicked. |
|
|
|
If you enter a value and click Save, the values of the input fields are bound to like-named field values in a new record, and that record |
|
is inserted. In other words, the <apex:inputField> component produces an input field for the name field of a new account |
|
record, and when you click Save, ensures that the value you entered is automatically saved to that field. |
|
|
|
After you click Save, the platform displays the newly-created record. Return to your Visualforce page by entering its URL, which will look |
|
something like https://na6.salesforce.com/apex/MyForm. |
|
|
|
21 |
|
|
|
Introduction to Visualforce |
|
|
|
Show Field Labels |
|
|
|
Show Field Labels |
|
|
|
Visualforce does a lot of work behind the scenes, binding the input field to a field on a new record. It can do more, such as automatically |
|
showing the field label (much like <apex:outputField> in Using Standard User Interface Components), as well as automatically |
|
changing the input element to match the data type (for example, showing a picklist instead of an input box). |
|
|
|
Modify the contents of the <apex:form> element so that it reads as follows: |
|
|
|
<apex:form> |
|
|
|
<apex:pageBlock> |
|
|
|
<apex:pageBlockSection> |
|
|
|
<apex:inputField value="{!account.name}"/> |
|
<apex:inputField value="{!account.industry}"/> |
|
<apex:commandButton action="{!save}" value="Save!"/> |
|
|
|
</apex:pageBlockSection> |
|
|
|
</apex:pageBlock> |
|
|
|
</apex:form> |
|
|
|
By encapsulating the input fields within <apex:pageBlock> and <apex:pageBlockSection> components, Visualforce |
|
automatically inserts field labels (“Account Name”, “Industry”) as well as indicators of whether values are required for the fields, all using |
|
the platform styles. |
|
|
|
Display Warning and Error Messages |
|
|
|
The <apex:pageMessages> component displays all information, warning or error messages that were generated for all components |
|
on the current page. In the previous form, the account name was a required field. To ensure that a standard error message is displayed |
|
if someone tries to submit the form without supplying an account name, do the following: |
|
|
|
1. Update your page by inserting the following line after the <apex:pageBlock> tag: |
|
|
|
<apex:pageMessages/> |
|
|
|
2. Now click Save on the form. An error panel will be displayed: |
|
|
|
Summary |
|
|
|
Visualforce’s standard controllers contain methods that make it easy to save and update records. By using the <apex:form> and |
|
<apex:inputField> components, you can easily bind input fields to new records using the standard controllers. The user interface |
|
automatically produces input components that match the type of the field—for example displaying a calendar input for a Data type |
|
|
|
22 |
|
|
|
Introduction to Visualforce |
|
|
|
Reusing Pages with Templates |
|
|
|
field. The <apex:pageMessages> component can be used to group and display the information, warning and error messages |
|
across all components in the page. |
|
|
|
Learning More |
|
|
|
• You can use the <apex:commandLink> instead of the <apex:commandButton> component within a form to provide a |
|
|
|
link for form processing. |
|
|
|
• Use the quicksave() method instead of the save() method to insert or update an existing record without redirecting the |
|
|
|
user to the new record. |
|
|
|
• Use the <apex:pageBlockButtons> component to place command buttons when using the <apex:pageBlock> |
|
|
|
component. |
|
|
|
• Use the <apex:pageMessage> component (the singular, not the plural) to create custom messages. |
|
|
|
Reusing Pages with Templates |
|
|
|
Many web sites have a design element that appears on every page, for example a banner or sidebar. You can duplicate this effect in |
|
Visualforce by creating a skeleton template that allows other Visualforce pages to implement different content within the same standard |
|
structure. Each page that uses the template can substitute different content for the placeholders within the template. |
|
|
|
Create a Template |
|
|
|
Templates are Visualforce pages containing special tags that designate placeholder text insertion positions. In this lesson you create a |
|
simple template page that uses the <apex:insert> component to specify the position of placeholder text. |
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1. Create a new Visualforce page called BasicTemplate. |
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2. Use the following as the body of the page: |
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<apex:page> |
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<h1>My Fancy Site</h1> |
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<apex:insert name="body"/> |
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</apex:page> |
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The key here is the <apex:insert> component. You won’t visit this page (unless developing it) directly. Rather, create another |
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Visualforce page that embeds this template, inserting different values for each of the <apex:insert> components. Note that each |
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such component is named. In the above template, you have a single insert position named body. You can have dozens of such positions. |
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Use a Template with Another Page |
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You can now embed the template in a new page, filling in the blanks as you go. |
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1. Create a new Visualforce page called MainPage. |
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2. Within the page, add the following markup: |
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<apex:page sidebar="false" showHeader="false"> |
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<apex:composition template="BasicTemplate"> |
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<apex:define name="body"> |
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<p>This is a simple page demonstrating that this |
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text is substituted, and that a banner is created.</p> |
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</apex:define> |
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23 |
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Introduction to Visualforce |
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Include One Visualforce Page within Another |
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</apex:composition> |
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</apex:page> |
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The <apex:composition> component fetches the Visualforce template page you created earlier, and the <apex:define> |
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component fills the named holes in that template. You can create multiple pages that use the same component, and just vary the |
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placeholder text. |
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Include One Visualforce Page within Another |
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Another way to include content from one page into another is to use the <apex:include> component. This lets you duplicate the |
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entire contents of another page, without providing any opportunity to make any changes as you did with the templates. |
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1. Create a new Visualforce page called EmbedsAnother. |
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2. Use the following markup in the page: |
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<apex:page sidebar="false" showHeader="false"> |
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<p>Test Before</p> |
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<apex:include pageName="MainPage"/> |
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<p>Test After</p> |
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</apex:page> |
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Your original MainPage will be inserted verbatim. |
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Summary |
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Templates are a nice way to encapsulate page elements that need to be reused across several Visualforce pages. Visualforce pages just |
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need to embed the template and define the content for the placeholders within the template. The <apex:include> component |
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provides a simpler way of embedding one page within another. |
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24 |
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INTRODUCTION TO APEX |
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Force.com Apex is a strongly-typed, object-oriented programming language that allows you to write code that executes on the Force.com |
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platform. Out of the box, Force.com provides a lot of high-level services, such as Web services, scheduling of code execution, batch |
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processing, triggers—and Visualforce back-end logic. All of these require you to write Apex. |
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In this section we’ll start with some set up, and then write some very simple Apex to introduce you to the tools. Then we’ll jump right |
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into the deep end, and you’ll learn enough Apex to create your first “real” Apex class. The code you’ll add to your organization will provide |
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custom functionality that you’ll use in the following section, to create a mobile-aware Visualforce page that you deploy to Salesforce1. |
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This section does assume you know a little about programming. If you don’t, you’ll still be able to complete the exercises, but you might |
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not understand every aspect. (And that’s OK!) |
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When you’re finished with this section, you will have done the following. |
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• Open the Developer Console, the advanced development tool for Force.com, and use it to create, edit, and run Apex code. |
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• Execute Apex code snippets in the Execute Anonymous Apex window. (You’ll even know what “anonymous Apex” means!) |
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• Create Apex classes and methods. |
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• Know some of the similarities and differences between Apex and other programming languages, such as Java, C#, and PHP. |
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• Execute a SOQL query in Apex, and process the results of that query. |
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• Create and run tests that verify the correct behavior of your Apex code, and understand what code coverage is and how to check |
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it. |
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Set Up Your Development Environment |
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In this short lesson, you’ll prepare your DE org for the exercises that follow. You’ll install a package with some supplementary resources, |
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load the Salesforce1 browser testing environment, and install the Salesforce1 mobile app on your mobile device of choice. |
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Install the Enhanced Warehouse Data Model |
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To prepare your developer organization for the exercises in this and the following section, you need to import the Warehouse data |
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model and sample data. |
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You might be familiar with the Warehouse app if you’ve gone through tutorials in other workbooks, or at a hands-on workshop. The |
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Warehouse app used here is an enhanced version that includes additional custom objects and data, and some supporting code. |
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1. |
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2. |
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In your browser go to http://bit.ly/warehouse_schema11 |
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If you’re already logged in, you’re redirected to the Package Installation Details page. Otherwise, log in with your Developer Edition |
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credentials. |
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3. Click Continue, Next, Next, and Install. |
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4. After the installation finishes, click the Force.com app menu and select Warehouse. |
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5. Click the Data tab and then click the Create Data button. |
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The package contains a pre-built Visualforce page, as well as some supporting resources. You’ll learn about them right after your |
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development and testing environments are set up. |
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25 |
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Introduction to Apex |
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Access the Mobile Browser Web App |
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Access the Mobile Browser Web App |
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When developing Visualforce pages for the Salesforce1 mobile app, you don’t want to use the familiar |
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https://<instance>/apex/<pageName> URL to view the page: you want to see how the pages look in the mobile app. |
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The best way to test your pages is with the actual mobile app, because it provides the most realistic experience. However, since it’s a |
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pain to grab your phone every time you want to see a change, you can open a new browser tab and use the one.app mobile browser |
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version. |
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1. |
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In your browser, open a new tab. |
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2. Copy and paste your Salesforce instance home URL into the address bar of the new tab, and add /one/one.app to the end. |
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For example, if your Salesforce instance has an URL of https://na4.salesforce.com, use |
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https://na4.salesforce.com/one/one.app. |
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3. Press Return to load the edited URL. |
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You should now see the mobile browser version of Saleforce1. As you go through the exercises in this workbook, you can develop in |
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one tab and then test in the other! |
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Important: The /one/one.app version is great for development, but you should always test on the actual devices and |
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browsers that you intend to support. |
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Download the Salesforce1 Mobile App |
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For final testing of the app you’re about to build, you’ll need to install the Salesforce1 mobile app on your device. |
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If you’ve already downloaded the Salesforce1 mobile app, you can skip this step. |
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1. Use your mobile device’s browser to go to www.salesforce.com/mobile, select the appropriate platform, and download |
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Salesforce1. |
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2. Open Salesforce1 from your mobile device. |
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3. Enter your Salesforce credentials and tap Log in to Salesforce. |
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4. |
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If you’re prompted to allow access to your data, tap OK and continue. |
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If you haven’t already explored Salesforce1, now is a great time to check it out. Being familiar with its functionality will help you create |
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apps that work well inside it. |
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Using the Developer Console |
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The Developer Console lets you execute Apex code statements. It also lets you execute Apex methods within an Apex class or object. |
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In this tutorial you open the Developer Console, execute some basic Apex statements, and toggle a few log settings. |
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Activating the Developer Console |
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After logging into your Salesforce environment, the screen displays the current application you’re using (in the diagram below, it’s |
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Warehouse), as well as your name. |
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1. Click Your name > Developer Console. |
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26 |
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Introduction to Apex |
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Using the Developer Console to Execute Apex Code |
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The Developer Console opens in a separate window. |
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Note: If you don’t see the Developer Console option, you might not be using an appropriate type of Force.com |
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environment—see “Before You Begin” at the beginning of this workbook for more information. |
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2. |
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If this is your first time opening the Developer Console, you can take a tour of the Developer Console features. Click Start Tour to |
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learn more about the Developer Console. |
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You can open the Developer Console at any time. |
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Using the Developer Console to Execute Apex Code |
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The Developer Console can look overwhelming, but it’s just a collection of tools that help you work with code. In this lesson, you’ll |
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execute Apex code and view the results in the Log Inspector. The Log Inspector is a useful tool you’ll use often. |
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1. Click Debug > Open Execute Anonymous Window or CTRL+E. |
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2. |
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In the Enter Apex Code window, enter the following text: System.debug( 'Hello World' ); |
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Note: System.debug() is like using System.out.println() in Java (or printf() if you’ve been around a |
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while ;-). But, when you’re coding in the cloud, where does the output go? Read on! |
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3. Deselect Open Log and then click Execute. |
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Every time you execute code, a log is created and listed in the Logs panel. |
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Double-click a log to open it in the Log Inspector. You can open multiple logs at a time to compare results. |
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27 |
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|
Introduction to Apex |
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Using the Developer Console to Execute Apex Code |
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Log Inspector is a context-sensitive execution viewer that shows the source of an operation, what triggered the operation, and what |
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occurred afterward. Use this tool to inspect debug logs that include database events, Apex processing, workflow, and validation logic. |
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The Log Inspector includes predefined perspectives for specific uses. Click Debug > Switch Perspective to select a different view, or |
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click CTRL+P to select individual panels. You’ll probably use the Execution Log panel the most. It displays the stream of events that occur |
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when code executes. Even a single statement generates a lot of events. The Log Inspector captures many event types: method entry |
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and exit, database and web service interactions, and resource limits. The event type USER_DEBUG indicates the execution of a |
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System.debug() statement. |
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1. Click Debug > Open Execute Anonymous Window or CTRL+E and enter the following code: |
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System.debug( 'Hello World' ); |
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System.debug( System.now() ); |
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System.debug( System.now() + 10 ); |
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2. Select Open Log and click Execute. |
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3. |
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In the Execution Log panel, select Executable. This limits the display to only those items that represent executed statements. For |
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example, it filters out the cumulative limits. |
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4. To filter the list to show only USER_DEBUG events, select Debug Only or enter USER in the Filter field. |
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Note: The filter text is case sensitive. |
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28 |
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Introduction to Apex |
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Summary |
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Congratulations—you have successfully executed code on the Force.com platform and viewed the results! |
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Tell Me More... |
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Help in the Developer Console |
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To learn more about the Developer Console, click Help > Help Docs… in the Developer Console. You can also take a number of |
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guided tours by starting with Help > Take the tour and choosing a feature to learn more about. |
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Anonymous Blocks |
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The Developer Console allows you to execute code statements on the fly. You can quickly evaluate the results in the Logs panel. |
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The code that you execute in the Developer Console is referred to as an anonymous block. Anonymous blocks run as the current |
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user and can fail to compile if the code violates the user’s object- and field-level permissions. Note that this isn’t the case for Apex |
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classes and triggers. |
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Summary |
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To execute Apex code and view the results of the execution, use the Developer Console. The detailed execution results include not only |
|
the output generated by the code, but also events that occur along the execution path. Such events include the results of calling another |
|
piece of code and interactions with the database. |
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Creating and Instantiating Classes |
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Apex is an object-oriented programming language, and much of the Apex you write will be contained in classes, sometimes referred |
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to as blueprints or templates for objects. In this tutorial you’ll create a simple class with two methods, and then execute them from the |
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Developer Console. |
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Creating an Apex Class Using the Developer Console |
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To create an Apex class in the Developer Console: |
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1. Click Your Name > Developer Console to open the Developer Console. |
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2. Click File > New > Apex Class. |
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3. Enter HelloWorld for the name of the new class and click OK. |
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29 |
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|
Introduction to Apex |
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Creating an Apex Class Using the Developer Console |
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4. A new empty HelloWorld class is created. Add a static method to the class by adding the following text between the braces: |
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public static void sayYou() { |
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System.debug( 'You' ); |
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} |
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5. Add an instance method by adding the following text just before the final closing brace: |
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public void sayMe() { |
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System.debug( 'Me' ); |
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} |
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6. Click File > Save. |
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Tell Me More... |
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• You’ve created a class called HelloWorld with a static method sayYou() and an instance method sayMe(). Looking at |
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the definition of the methods, you’ll see that they call another class, System, invoking the method debug() on that class, which |
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will output strings. |
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• If you invoke the sayYou() method of your class, it invokes the debug() method of the System class, and you see the |
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output. |
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• The Developer Console validates your code in the background to ensure that the code is syntactically correct and compiles successfully. |
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Making mistakes, such as typos in your code, is inevitable. If you make a mistake in your code, errors appear in the Problems pane |
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and an exclamation mark is added next to the pane heading: Problems!. |
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• Expand the Problems panel to see a list of errors. Clicking on an error takes you to the line of code where this error is found. For |
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example, the following shows the error that appears after you omit the closing parenthesis at the end of the System.debug |
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statement. |
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30 |
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|
Introduction to Apex |
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Calling a Class Method |
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Re-add the closing parenthesis and notice that the error goes away. |
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Calling a Class Method |
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Now that you’ve created the HelloWorld class, follow these steps to call its methods. |
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1. Execute the following code in the Developer Console Execute Anonymous Window to call the HelloWorld class’s static method. |
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(See Activating the Developer Console if you’ve forgotten how to do this.) If there is any existing code in the entry panel, delete it |
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first. Notice that to call a static method, you don’t have to create an instance of the class. |
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HelloWorld.sayYou(); |
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2. Open the resulting log. |
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3. Set the filters to show USER_DEBUG events. (Also covered in Activating the Developer Console). “You” appears in the log: |
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4. Now execute the following code to call the HelloWorld class’s instance method. Notice that to call an instance method, you |
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first have to create an instance of the HelloWorld class. |
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HelloWorld hw = new HelloWorld(); |
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hw.sayMe(); |
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5. Open the resulting log and set the filters. |
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“Me” appears in the Details column. This code creates an instance of the HelloWorld class, and assigns it to a variable called |
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hw. It then calls the sayMe() method on that instance. |
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6. Clear the filters on both logs, and compare the two execution logs. The most obvious differences are related to creating the |
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HelloWorld instance and assigning it to the variable hw. Do you see any other differences? |
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31 |
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|
Introduction to Apex |
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Creating an Apex Class Using the Salesforce User Interface |
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|
Congratulations—you have now successfully created and executed new code on the Force.com platform! |
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|
Creating an Apex Class Using the Salesforce User Interface |
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|
You can also create an Apex class in the Salesforce user interface. |
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|
1. From Setup, click Develop > Apex Classes. |
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|
2. Click New. |
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3. |
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In the editor pane, enter the following code: |
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public class MessageMaker { |
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} |
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4. Click Quick Save. You could have clicked Save instead, but that closes the class editor and returns you to the Apex Classes list. Quick |
|
Save saves the Apex code, making it available to be executed, but lets you continue editing—making it easier to add to and modify |
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the code. |
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5. Add the following code to the class: |
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public static string helloMessage() { |
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return('You say "Goodbye," I say "Hello"'); |
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} |
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6. Click Save. |
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|
You can also view the class you’ve just created in the Developer Console and edit it. |
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|
1. |
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2. |
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In the Developer Console, click File > Open. |
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|
In the Entity Type panel, click Classes, and then double-click MessageMaker from the Entities panel. |
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|
The MessageMaker class displays in the source code editor. You can edit the code there by typing directly in the editor and |
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saving the class. |
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|
Summary |
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|
In this tutorial you learned how to create and list Apex classes. The classes and methods you create can be called from the Developer |
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Console, as well as from other classes and code that you write. |
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32 |
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|
Introduction to Apex |
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|
Creating the WarehouseUtils Class |
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Tell Me More... |
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• Alternatively, you can use the Force.com IDE to create and execute Apex code. For more information, search for “Force.com IDE” on |
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the Developer Force site: https://developer.salesforce.com/. |
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Creating the WarehouseUtils Class |
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|
In this exercise, we turn to real work. You’ll write a new Apex class that searches Salesforce to find records that match a query, and makes |
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those records available for use on a Visualforce page. |
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|
Here’s the scenario. You’re going to write a small app to give mobile technicians that work for the Acme Wireless organization a way to |
|
find nearby warehouses. For example, if the technician is out on a call and needs a part, they can use this page to look for warehouses |
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within a 20-mile radius. For each warehouse, a map should display a pin along with the warehouse name, address, and phone number. |
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|
The Apex and Visualforce code that you’re about to write will do all of that inside Salesforce1 on a mobile device. It’s going to be cool. |
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|
Create the WarehouseUtils Apex Class |
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First you need to define the new class and give it a constructor method. |
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|
Depending on where an Apex class is going to be used, you might need to conform to expected interfaces or conventions. For example, |
|
the WarehouseUtils class could be used two ways: as a Visualforce controller extension from a Visualforce page, and as a Remote |
|
Action from Visualforce JavaScript remoting. |
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|
A controller extension is used to extend the capabilities of a Visualforce controller, by adding additional functionality in the form of |
|
methods that can be called by the page. A Visualforce page can have only one controller, but can have one, none, or many controller |
|
extensions. |
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|
To be a controller extension, an Apex class needs to have a constructor that accepts a Visualforce controller as its only parameter. (We’ll |
|
look at the requirements for Remote Actions later.) |
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|
1. Go to Setup > Develop > Apex Classes and click New. |
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|
2. |
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|
In the Editor enter the following code. |
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global with sharing class WarehouseUtils { |
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public WarehouseUtils(ApexPages.StandardSetController controller) { } |
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// findNearbyWarehouses method goes here |
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} |
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3. Click Quick Save. |
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|
The constructor method takes a ApexPages.StandardSetController object as its only parameter. This allows the class to |
|
be used as a Visualforce controller extension with a Standard List Controller. To also work with a Standard Controller, overload the |
|
constructor to take a different parameter type. That is, add a second constructor method that takes an |
|
ApexPages.StandardController parameter. |
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public WarehouseUtils(ApexPages.StandardController controller) { } |
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|
These constructors are empty, but in a more complex controller extension you would save the controller as an instance variable. Do you |
|
think you know enough Apex by now to do that? Give it a try! |
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|
33 |
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|
Introduction to Apex |
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|
Add a “Stub” findNearbyWarehouses Method |
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|
Add a “Stub” findNearbyWarehouses Method |
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|
Next, stub in the method that will be used by the Visualforce page. |
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|
Each public and global method in a controller extension is available to be used by an associated Visualforce page. To call the method |
|
the page can reference it in an expression, or it can call the method directly using JavaScript remoting. |
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|
In this case, we want to create a method that will query for warehouses located near the mobile technician who is using the app. This |
|
means the method needs to know where the technician is located, so we’ll pass in latitude and longitude values that the Salesforce1 |
|
app can provide using the built-in geolocation capabilities of the device it’s running on. Visualforce expressions can’t take parameters |
|
directly, so we’re planning to use JavaScript remoting. For now, we’ll just write a method “stub” that takes latitude and longitude |
|
parameters, and returns a list of warehouse records. |
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|
1. |
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|
In your code editor, replace the comment line // findNearbyWarehouses method goes here with the following |
|
code. |
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|
// Find warehouses nearest a geolocation |
|
@RemoteAction |
|
global static List<Warehouse__c> findNearbyWarehouses(String lat, String lon) { |
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|
// Initialize results to an empty list |
|
List<Warehouse__c> results = new List<Warehouse__c>(); |
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|
// method implementation goes here |
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|
// Return the query results |
|
return(results); |
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|
} |
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2. Click Quick Save. |
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|
Although it doesn’t do anything yet, this method definition illustrates the essentials of an Apex method. |
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• global: The scope of the method. Methods to be called by JavaScript remoting, called Remote Actions, must be either global |
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or public. |
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|
• static: This is a class method, as opposed to an instance method. This means you can call the method without instantiating an |
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object of this class. Remote Action methods must be static. |
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|
• List<Warehouse__c>: The data type of the method’s return value. |
|
|
|
• findNearbyWarehouses: The name of the method. |
|
|
|
• (String lat, String lon): The method’s parameters. |
|
|
|
The remainder of the method, between the braces—what there is so far!—is the implementation. You’ll write that next! |
|
|
|
Perform a Query and Return the Results |
|
|
|
Now it’s time to write the actual method implementation, which will take the latitude and longitude values provided by the user’s device |
|
and find nearby warehouses. |
|
|
|
To search for the relevant records, you need to convert the provided parameters into a complete SOQL query. SOQL is the primary query |
|
language of the Force.com platform. You can use it in Apex, as we’ll do here, but you can use it with other Salesforce APIs as well. |
|
|
|
We’ll construct the query dynamically, using string concatenation to combine the necessary SOQL elements with the parameter values. |
|
Then we’ll execute the query, and return the results. |
|
|
|
34 |
|
|
|
Introduction to Apex |
|
|
|
Summary and Code Check |
|
|
|
1. |
|
|
|
Inside the method implementation block, replace the comment line // method implementation goes here with the |
|
following code. |
|
|
|
// SOQL query to get the nearest warehouses |
|
String queryString = |
|
|
|
'SELECT Id, Name, Location__Longitude__s, Location__Latitude__s, ' + |
|
|
|
'Street_Address__c, Phone__c, City__c ' + |
|
|
|
'FROM Warehouse__c ' + |
|
'WHERE DISTANCE(Location__c, GEOLOCATION('+lat+','+lon+'), \'mi\') < 20 ' + |
|
'ORDER BY DISTANCE(Location__c, GEOLOCATION('+lat+','+lon+'), \'mi\') ' + |
|
'LIMIT 10'; |
|
|
|
// Run the query |
|
results = database.Query(queryString); |
|
|
|
2. Click Quick Save. |
|
|
|
SOQL looks a lot like standard SQL, and if you know SQL already, you’ll pick up SOQL easily. See the Force.com SOQL and SOSL Reference |
|
for comprehensive details of the query language. |
|
|
|
Two aspects of the query might not be immediately obvious. |
|
|
|
• The GEOLOCATION() function creates a geolocation from a latitude and longitude. A geolocation represents a specific physical |
|
location. Here the function is used to combine the latitude and longitude parameters to create a value that represents the location |
|
of the user. |
|
|
|
• The DISTANCE() function calculates the distance between two geolocations. Here it’s calculating the distance between the |
|
|
|
Warehouse__c.Location__c geolocation field and the geolocation of the user. The query’s WHERE clause is looking for |
|
DISTANCE() values within 20 miles. |
|
|
|
Summary and Code Check |
|
|
|
You did it! You wrote a new Apex utility class that you’ll be able to use with a Visualforce page. |
|
|
|
Your completed class should look like the following. |
|
|
|
global with sharing class WarehouseUtils { |
|
|
|
public WarehouseUtils(ApexPages.StandardSetController controller) { } |
|
|
|
// Find warehouses nearest a geolocation |
|
@RemoteAction |
|
global static List<Warehouse__c> findNearbyWarehouses(String lat, String lon) { |
|
|
|
// Initialize results to an empty list |
|
List<Warehouse__c> results = new List<Warehouse__c>(); |
|
|
|
// SOQL query to get the nearest warehouses |
|
String queryString = |
|
|
|
'SELECT Id, Name, Location__Longitude__s, Location__Latitude__s, ' + |
|
|
|
'Street_Address__c, Phone__c, City__c ' + |
|
|
|
'FROM Warehouse__c ' + |
|
'WHERE DISTANCE(Location__c, GEOLOCATION('+lat+','+lon+'), \'mi\') < 20 ' + |
|
'ORDER BY DISTANCE(Location__c, GEOLOCATION('+lat+','+lon+'), \'mi\') ' + |
|
'LIMIT 10'; |
|
|
|
35 |
|
|
|
Introduction to Apex |
|
|
|
Testing and Debugging the WarehouseUtils Class |
|
|
|
// Run the query |
|
results = database.Query(queryString); |
|
|
|
// Return the query results |
|
return(results); |
|
|
|
} |
|
|
|
} |
|
|
|
As exciting as it would be to race ahead and use this new code to make a cool Visualforce page, well...there’s a bug in the code. (Have |
|
you spotted it already?) So, before we go further, you’ll want to learn a bit about testing and debugging Apex code. |
|
|
|
Testing and Debugging the WarehouseUtils Class |
|
|
|
In this exercise, we need to take our new Apex class and verify that it functions as intended. Using the Apex unit testing framework, |
|
you’ll write tests and debug your new code. |
|
|
|
Writing unit tests for your code is fundamental to developing Apex code. You must have 75% test coverage to be able to deploy your |
|
Apex code to your production organization. In addition, the tests counted as part of the test coverage must pass. Testing is key to ensuring |
|
the quality of your application. Furthermore, having a set of tests that you can rerun in the future if you have to make changes to your |
|
code allows you to catch any potential regressions to the existing code. |
|
|
|
Testing might seem like an obstacle to getting to the “fun” part of your project. But when you see how easy it is, perhaps you’ll change |
|
your mind. |
|
|
|
Create an Apex Test Class |
|
|
|
Unit tests are contained in Apex classes and, with a few small additions, look just like regular Apex classes. |
|
|
|
Test classes use annotations that mark them as test classes. Test classes don’t count against your organization’s code size limits. |
|
|
|
1. |
|
|
|
In the Developer Console, click File > New > Apex Class. |
|
|
|
2. For the class name, enter TestWarehouseUtils and click OK. |
|
|
|
3. |
|
|
|
In the editor, delete the auto-generated code and replace it with the following. |
|
|
|
@isTest |
|
private class TestWarehouseUtils { |
|
|
|
// test methods go here |
|
|
|
} |
|
|
|
The @isTest annotation tells Force.com that all of the code within the Apex class is test code. It’s a best practice to keep your test |
|
code private. The Apex test framework can find and run your tests, but nothing else should be able to. |
|
|
|
Note: If you create test helper or utility classes that are used by separate test classes, they’ll need to be public. |
|
|
|
Add a Test Method and Setup Code |
|
|
|
Define test methods within your test class to add them to your organization’s test suite. |
|
|
|
The WarehouseUtils class has only one method, but there are a few things we’d like to test it for. Calling the method should return |
|
all warehouses located within 20 miles of a specific location. The method should also return none of the warehouses that are outside |
|
|
|
36 |
|
|
|
Introduction to Apex |
|
|
|
Add a Test Method and Setup Code |
|
|
|
of that 20 mile radius. Finally, locations that appear nearby one location should no longer be nearby if the requested location changes |
|
to being far away. We’ll create two test methods to cover these expectations. |
|
|
|
In order to test these expectations, we’ll need a few test warehouses with known distances from our test location. The Apex test framework |
|
makes it easy to create tests that use test data, and only test data, during the course of the test execution. This is called test isolation. Your |
|
organization’s data is hidden from tests by default, and your test data and any changes to data that the tests perform are all rolled back |
|
at the end of test execution. But since we’re not testing against the data in your organization, our tests will have to create their own |
|
data. We’ll create a few helper methods to handle that, too. |
|
|
|
1. |
|
|
|
In the test class you created in the last step, we’ll add two new test method stubs and a few helper methods. Inside the class definition |
|
block, replace the comment line // test methods go here with the following code. |
|
|
|
// test that we find only warehouses that are within 20 miles |
|
static testMethod void testFindWarehousesWithinTwentyMiles() { |
|
|
|
// test for when close to warehouses here |
|
|
|
} |
|
|
|
// test that we don't find anything when further than 20 miles |
|
static testMethod void testDontFindWarehousesFurtherThanTwentyMiles() { |
|
|
|
// test for when far from warehouses here |
|
|
|
} |
|
|
|
// helper methods to create test data |
|
static Warehouse__c createTestWarehouse(String name, Decimal lat, Decimal lon) { |
|
|
|
Warehouse__c w = new Warehouse__c( |
|
|
|
Name = name, |
|
Location__Latitude__s = lat, |
|
Location__Longitude__s = lon |
|
|
|
); |
|
insert w; |
|
return w; |
|
|
|
} |
|
|
|
static Warehouse__c createClosestTestWarehouse() { |
|
|
|
// Federal Reserve Bank of SF, next door to Salesforce HQ |
|
return(createTestWarehouse('Warehouse1', 37.7927731, -122.4010922)); |
|
|
|
} |
|
|
|
static Warehouse__c createCloseTestWarehouse() { |
|
|
|
// Moscone Center, home of Dreamforce |
|
return(createTestWarehouse('Warehouse2', 37.783944, -122.401289)); |
|
|
|
} |
|
|
|
static Warehouse__c createTooFarTestWarehouse() { |
|
|
|
// Mount Rushmore, South Dakota |
|
return(createTestWarehouse('TooFarWarehouse', 43.879102, -103.459067)); |
|
|
|
} |
|
|
|
The test method definitions are static testMethod void testName(), with no parameters. Right now this test class |
|
doesn’t test anything—we still need to fill in the actual test code. |
|
|
|
37 |
|
|
|
Introduction to Apex |
|
|
|
Test the findNearbyWarehouses Method |
|
|
|
The helper methods don’t have testMethod in their definition, and can take parameters and return values. Other than being static, |
|
they can be any kind of method you need them to be. Here their only function is to create new, pre-defined warehouse objects and |
|
save them into the database. |
|
|
|
Your tests and helpers can insert, change, and delete records as much as you need them to fully exercise your code. Remember, all |
|
database interaction takes place in an isolated, test-only environment. No changes performed by the tests will be saved permanently. |
|
|
|
Test the findNearbyWarehouses Method |
|
|
|
Write the least amount of code possible that will exercise your code and test its behavior. Test one thing at a time. |
|
|
|
You have two test method implementations to write. One will test calling WarehouseUtils.findNearbyWarehouses from |
|
a location that is close by some warehouses, and one will test calling WarehouseUtils.findNearbyWarehouses from a |
|
location that’s not near any warehouses. |
|
|
|
1. |
|
|
|
Inside the testFindWarehousesWithinTwentyMiles method replace the comment line // test for when |
|
close to warehouses here with the following code. |
|
|
|
// Salesforce HQ |
|
String myLat = '37.793731'; |
|
String myLon = '-122.395002'; |
|
|
|
// Create test warehouse data |
|
Warehouse__c closestWarehouse = createClosestTestWarehouse(); |
|
Warehouse__c closeWarehouse = createCloseTestWarehouse(); |
|
Warehouse__c tooFarWarehouse = createTooFarTestWarehouse(); |
|
|
|
// Perform the test execution |
|
Test.startTest(); |
|
List<Warehouse__c> nearbyWarehouses = |
|
|
|
WarehouseUtils.findNearbyWarehouses(myLat, myLon); |
|
|
|
Test.stopTest(); |
|
|
|
// Make assertions about expected results |
|
|
|
// We expect two warehouses |
|
System.assert(nearbyWarehouses.size() == 2); |
|
|
|
// We expect two SPECIFIC warehouses, in order of proximity |
|
System.assert(nearbyWarehouses[0].Name == closestWarehouse.Name); |
|
System.assert(nearbyWarehouses[1].Name == closeWarehouse.Name); |
|
|
|
// We do NOT expect to see the warehouse that's too far away |
|
if(0 < nearbyWarehouses.size()) { |
|
|
|
for (Warehouse__c wh : nearbyWarehouses) { |
|
|
|
System.assert(wh.Name != tooFarWarehouse.Name); |
|
|
|
} |
|
|
|
} |
|
|
|
2. |
|
|
|
Inside the testDontFindWarehousesFurtherThanTwentyMiles method replace the comment line // test |
|
for when far from warehouses here with the following code. |
|
|
|
// Eiffel Tower, Paris, France |
|
String myLat = '48.85837'; |
|
String myLon = '2.294481'; |
|
|
|
38 |
|
|
|
Introduction to Apex |
|
|
|
Run the Test and Review Test Results |
|
|
|
// Create test warehouse data |
|
Warehouse__c closestWarehouse = createClosestTestWarehouse(); |
|
Warehouse__c closeWarehouse = createCloseTestWarehouse(); |
|
Warehouse__c tooFarWarehouse = createTooFarTestWarehouse(); |
|
|
|
// Perform the test execution |
|
Test.startTest(); |
|
List<Warehouse__c> nearbyWarehouses = |
|
|
|
WarehouseUtils.findNearbyWarehouses(myLat, myLon); |
|
|
|
Test.stopTest(); |
|
|
|
// We expect to see NO warehouses |
|
System.assert(nearbyWarehouses.size() == 0); |
|
|
|
The test methods follow a simple pattern. |
|
|
|
• Perform required setup, including creation of test data. |
|
|
|
• Perform the test execution, wrapped inside Test.startTest() and Test.endTest() test framework calls. |
|
|
|
• Compare the results of the test execution with known data. That is, compare actual behavior to expected behavior. |
|
|
|
This is a good pattern to follow in your own test code. It’s also a best practice to test only one thing at a time, and to put each test into |
|
a separate method. |
|
|
|
Run the Test and Review Test Results |
|
|
|
The Force.com test framework makes it easy to run your tests, and provides test run results and test coverage analysis for your tested |
|
code. |
|
|
|
Running a good test suite and getting clean results is one of the most satisfying things you can do as a programmer. Let’s get that warm |
|
fuzzy feeling right now. |
|
|
|
1. |
|
|
|
In the Developer Console, click Test > New Run. |
|
|
|
2. Click TestWarehouseUtils, and then click > to add your test class to the rest run. |
|
|
|
3. Click Run to execute the test run. |
|
|
|
The test result displays in the Tests tab. You can expand the test run folder and then expand the test class in the Tests tab to see |
|
which methods were run. In this case, the class contains two test methods. |
|
|
|
4. The Overall Code Coverage pane shows the code coverage of this test class, which is 83%. The output you’ll see is similar to the |
|
|
|
following. The code coverage for the WarehouseUtils class is outlined. |
|
|
|
The result tells you a number of important things. |
|
|
|
39 |
|
|
|
Introduction to Apex |
|
|
|
Run the Test and Review Test Results |
|
|
|
• It indicates whether your tests passed or not. If the Boolean condition in the System.assert statements in the tests had |
|
failed—that is, if the assertion was false—then that failure would be flagged here. Adding lots of assertions is a great way |
|
to verify the expected behavior of your code. |
|
|
|
• It provides detail about the execution of the test. By looking through the associated debug log in the Logs tab, for example, you |
|
|
|
see which methods executed, which records were created or modified, how many queries were executed, and so on. |
|
|
|
• It indicates code coverage by percentage and by how many lines of code were executed in each affected class. |
|
|
|
The results page shows that we achieved 83% coverage of the WarehouseUtils class. That’s enough code coverage to deploy, |
|
but why not aim for perfection? Let’s see what’s being missed. |
|
|
|
5. |
|
|
|
In the Overall Code Coverage pane, double-click the line for the WarehouseUtils class coverage. |
|
The Code Coverage page opens. Blue highlighting indicates lines of code that were covered (executed) during the test execution. |
|
Lines with red highlighting indicates lines of code that weren’t executed. |
|
|
|
In this case, line 3—our empty constructor method—wasn’t executed because we only called static methods, and so never instantiated |
|
the class. While an empty constructor is no big deal, getting coverage on it is also no big deal. |
|
|
|
6. Add the following new test method to your test class. |
|
|
|
// test the class constructor |
|
static testMethod void testClassConstructor() { |
|
|
|
Test.startTest(); |
|
WarehouseUtils utils = new WarehouseUtils(null); |
|
Test.stopTest(); |
|
|
|
// We expect that utils is not null |
|
System.assert(utils != null); |
|
|
|
} |
|
|
|
If you re-run your tests, you should have 100% code coverage. Woo-hoo! |
|
|
|
40 |
|
|
|
Introduction to Apex |
|
|
|
Find the Bug |
|
|
|
Code coverage refers to how much of your production code (in this case, the WarehouseUtils class) is covered by your test code |
|
(the test class you just wrote). In other words, when you run your test code, does it execute all, or only some portion of, your production |
|
code? If it only executes a portion of the code, that could mean your production code still has bugs in the untested portions. The code |
|
coverage view makes that easy to visualize. |
|
|
|
Note: Some of the code isn’t highlighted either blue or red. What does that mean? For example, the class declaration, the |
|
@RemoteAction annotation, and comments aren’t highlighted, which makes some sense, but neither are the additional lines |
|
of the queryString expression. What’s up with that? |
|
|
|
All of these lines are considered non-executable by the compiler, which is doing the work of highlighting. When you break a line |
|
of code across multiple lines in your editor, only the first line is highlighted, either way. |
|
|
|
Find the Bug |
|
|
|
A completely passing test suite doesn’t always mean there aren’t any bugs. It might just mean you haven’t found them. Yet. |
|
|
|
Yes, there’s a bug in the version of WarehouseUtils we currently have. Technically, since it’s your DE org, it’s your bug, but we’ll |
|
admit to leading you a bit astray. Let’s find and fix it together. |
|
|
|
You might have already figured it out, but just in case, here’s a hint. What happens if we call |
|
WarehouseUtils.findNearbyWarehouses with invalid values for the latitude or longitude? |
|
|
|
Let’s try it and see. We can quickly run a short snippet of Apex code in the Execute Anonymous window, and see what happens. |
|
|
|
1. |
|
|
|
In the Developer Console, click Debug > Open Execute Anonymous Window. |
|
|
|
2. Add the following code, and then click Execute. |
|
|
|
List<Warehouse__c> warehouses = WarehouseUtils.findNearbyWarehouses(null, null); |
|
for(Warehouse__c wh : warehouses) { |
|
|
|
System.debug(wh.Name); |
|
|
|
} |
|
|
|
The result is an error in the Execute Anonymous window, “System.QueryException: unexpected token: 'null'”. It turns out the |
|
GEOLOCATION function doesn’t like invalid latitude or longitude values. Who knew? |
|
|
|
The good news is, this gives us a chance to fix the bug like pros: by writing the test first. |
|
|
|
Write a Test for the Bug |
|
|
|
Test-first development is the practice of writing tests for a feature before you write the code to implement the feature. |
|
|
|
Because the feature isn’t implemented yet, the tests will fail. Then you implement the feature and run the tests again. When they pass, |
|
you have some confidence that you’ve implemented the feature correctly. Repeating this cycle as you develop new features increases |
|
your confidence in the software implementation. |
|
|
|
1. |
|
|
|
In the TestWarehouseUtils test class, add the following new test method. |
|
|
|
// test that we use a default location if the lat or long is invalid |
|
static testMethod void testFindWarehousesDefaultLocation() { |
|
// Trigger the default location, which should be SF |
|
String myLat = null; |
|
String myLon = null; |
|
|
|
// Create test warehouse data |
|
Warehouse__c closestWarehouse = createClosestTestWarehouse(); |
|
|
|
41 |
|
|
|
Introduction to Apex |
|
|
|
Fix the Bug |
|
|
|
Warehouse__c closeWarehouse = createCloseTestWarehouse(); |
|
Warehouse__c tooFarWarehouse = createTooFarTestWarehouse(); |
|
|
|
// Perform the test execution |
|
Test.startTest(); |
|
List<Warehouse__c> nearbyWarehouses = |
|
|
|
WarehouseUtils.findNearbyWarehouses(myLat, myLon); |
|
|
|
Test.stopTest(); |
|
|
|
// Make assertions about expected results |
|
|
|
// We expect two warehouses |
|
System.assert(nearbyWarehouses.size() == 2); |
|
|
|
// We expect two SPECIFIC warehouses, in order of proximity |
|
System.assert(nearbyWarehouses[0].Name == closestWarehouse.Name); |
|
System.assert(nearbyWarehouses[1].Name == closeWarehouse.Name); |
|
|
|
// We do NOT expect to see the warehouse that's too far away |
|
if(0 < nearbyWarehouses.size()) { |
|
|
|
for (Warehouse__c wh : nearbyWarehouses) { |
|
|
|
System.assert(wh.Name != tooFarWarehouse.Name); |
|
|
|
} |
|
|
|
} |
|
|
|
} |
|
|
|
2. Save the updated test class, and re-run your tests. |
|
|
|
The result of re-running the test suite with the new test should be a failure. This means the test is working, and detecting that your |
|
production code is not working as intended. |
|
|
|
Fix the Bug |
|
|
|
Once you have a test that verifies and isolates incorrect behavior in your code, it’s often straightforward to fix the issue. The reward for |
|
doing so is a passing test suite. |
|
|
|
We know that the findNearbyWarehouses method fails with an error when it’s called with blank latitude or longitude values. |
|
Checking for missing or empty values is pretty easy to do. |
|
|
|
1. |
|
|
|
In the WarehouseUtils class, after results is initialized to an empty list and before the query string is assembled, add the following |
|
code. |
|
|
|
// If geolocation parameters are invalid, use San Francisco |
|
if(String.isBlank(lat) || String.isBlank(lon)) { |
|
|
|
lat = '37.793731'; |
|
lon = '-122.395002'; |
|
|
|
} |
|
|
|
2. Save your changes, and re-run your test suite. |
|
|
|
And, that should do it. Once again, you have a passing test suite. |
|
|
|
Before we leave the topic of Apex and testing, take a look at the new code you’ve just added. Will that if condition catch all possible |
|
invalid latitude and longitude values? What could you add? Should that all go into the if condition? Do you feel ready to add a helper |
|
|
|
42 |
|
|
|
Introduction to Apex |
|
|
|
Summary and Code Check |
|
|
|
method to the class that could check lat and lon for validity? How would you do that? Should the helper method be public or |
|
private? |
|
|
|
Here’s another stretch exercise. There are now a few hard-coded latitude and longitude values in both WarehouseUtils and |
|
TestWarehouseUtils. What assures you that those numbers will stay in sync? What happens if they get out of sync? Think about |
|
those assertions. What happens if a typo in a latitude or longitude value causes the test location to “drift” away from one test warehouse |
|
and closer to the other? |
|
|
|
Summary and Code Check |
|
|
|
You just finished writing a test suite for your Apex class. You also learned how to create test runs that execute your tests, and how to |
|
check the code coverage of your test suite. |
|
|
|
Having a complete set of tests to verify correct behavior of your code is necessary for deployment and it’s also the key to successful |
|
long-term development. |
|
|
|
Your complete test class should look like this. |
|
|
|
@isTest |
|
private class TestWarehouseUtils { |
|
|
|
// test that we find only warehouses that are within 20 miles |
|
static testMethod void testFindWarehousesWithinTwentyMiles() { |
|
|
|
// Salesforce HQ |
|
String myLat = '37.793731'; |
|
String myLon = '-122.395002'; |
|
|
|
// Create test warehouse data |
|
Warehouse__c closestWarehouse = createClosestTestWarehouse(); |
|
Warehouse__c closeWarehouse = createCloseTestWarehouse(); |
|
Warehouse__c tooFarWarehouse = createTooFarTestWarehouse(); |
|
|
|
// Perform the test execution |
|
Test.startTest(); |
|
List<Warehouse__c> nearbyWarehouses = |
|
|
|
WarehouseUtils.findNearbyWarehouses(myLat, myLon); |
|
|
|
Test.stopTest(); |
|
|
|
// Make assertions about expected results |
|
|
|
// We expect two warehouses |
|
System.assert(nearbyWarehouses.size() == 2); |
|
|
|
// We expect two SPECIFIC warehouses, in order of proximity |
|
System.assert(nearbyWarehouses[0].Name == closestWarehouse.Name); |
|
System.assert(nearbyWarehouses[1].Name == closeWarehouse.Name); |
|
|
|
// We do NOT expect to see the warehouse that's too far away |
|
if(0 < nearbyWarehouses.size()) { |
|
|
|
for (Warehouse__c wh : nearbyWarehouses) { |
|
|
|
System.assert(wh.Name != tooFarWarehouse.Name); |
|
|
|
} |
|
|
|
} |
|
|
|
} |
|
|
|
43 |
|
|
|
Introduction to Apex |
|
|
|
Summary and Code Check |
|
|
|
// test that we don't find anything further than 20 miles |
|
static testMethod void testDontFindWarehousesFurtherThanTwentyMiles() { |
|
|
|
// Eiffel Tower, Paris, France |
|
String myLat = '48.85837'; |
|
String myLon = '2.294481'; |
|
|
|
// Create test warehouse data |
|
Warehouse__c closestWarehouse = createClosestTestWarehouse(); |
|
Warehouse__c closeWarehouse = createCloseTestWarehouse(); |
|
Warehouse__c tooFarWarehouse = createTooFarTestWarehouse(); |
|
|
|
// Perform the test execution |
|
Test.startTest(); |
|
List<Warehouse__c> nearbyWarehouses = |
|
|
|
WarehouseUtils.findNearbyWarehouses(myLat, myLon); |
|
|
|
Test.stopTest(); |
|
|
|
// We expect to see NO warehouses |
|
System.assert(nearbyWarehouses.size() == 0); |
|
|
|
} |
|
|
|
// test the class constructor |
|
static testMethod void testClassConstructor() { |
|
|
|
Test.startTest(); |
|
WarehouseUtils utils = new WarehouseUtils(null); |
|
Test.stopTest(); |
|
|
|
// We expect that utils is not null |
|
System.assert(utils != null); |
|
|
|
} |
|
|
|
// test that we use a default location if the lat or long is invalid |
|
static testMethod void testFindWarehousesDefaultLocation() { |
|
// Trigger the default location, which should be SF |
|
String myLat = null; |
|
String myLon = null; |
|
|
|
// Create test warehouse data |
|
Warehouse__c closestWarehouse = createClosestTestWarehouse(); |
|
Warehouse__c closeWarehouse = createCloseTestWarehouse(); |
|
Warehouse__c tooFarWarehouse = createTooFarTestWarehouse(); |
|
|
|
// Perform the test execution |
|
Test.startTest(); |
|
List<Warehouse__c> nearbyWarehouses = |
|
|
|
WarehouseUtils.findNearbyWarehouses(myLat, myLon); |
|
|
|
Test.stopTest(); |
|
|
|
// Make assertions about expected results |
|
|
|
// We expect two warehouses |
|
System.assert(nearbyWarehouses.size() == 2); |
|
|
|
// We expect two SPECIFIC warehouses, in order of proximity |
|
|
|
44 |
|
|
|
Introduction to Apex |
|
|
|
Summary and Code Check |
|
|
|
System.assert(nearbyWarehouses[0].Name == closestWarehouse.Name); |
|
System.assert(nearbyWarehouses[1].Name == closeWarehouse.Name); |
|
|
|
// We do NOT expect to see the warehouse that's too far away |
|
if(0 < nearbyWarehouses.size()) { |
|
|
|
for (Warehouse__c wh : nearbyWarehouses) { |
|
|
|
System.assert(wh.Name != tooFarWarehouse.Name); |
|
|
|
} |
|
|
|
} |
|
|
|
} |
|
|
|
// helper methods to create test data |
|
static Warehouse__c createTestWarehouse(String name, Decimal lat, Decimal lon) { |
|
|
|
Warehouse__c w = new Warehouse__c( |
|
|
|
Name = name, |
|
Location__Latitude__s = lat, |
|
Location__Longitude__s = lon |
|
|
|
); |
|
insert w; |
|
return w; |
|
|
|
} |
|
|
|
static Warehouse__c createClosestTestWarehouse() { |
|
|
|
// Federal Reserve Bank of SF |
|
// Next door to Salesforce HQ |
|
return(createTestWarehouse('Warehouse1', 37.7927731, -122.4010922)); |
|
|
|
} |
|
|
|
static Warehouse__c createCloseTestWarehouse() { |
|
|
|
// Moscone Center, home of Dreamforce |
|
return(createTestWarehouse('Warehouse2', 37.783944, -122.401289)); |
|
|
|
} |
|
|
|
static Warehouse__c createTooFarTestWarehouse() { |
|
|
|
// Mount Rushmore, South Dakota |
|
return(createTestWarehouse('TooFarWarehouse', 43.879102, -103.459067)); |
|
|
|
} |
|
|
|
} |
|
|
|
45 |
|
|
|
VISUALFORCE AND APEX IN ACTION |
|
|
|
In the previous sections of the workbook you learned about Visualforce and Apex separately. Like two great tastes that taste great |
|
together, Visualforce and Apex are better—more powerful, more flexible, more versatile—when combined. In this section, you’ll put |
|
Visualforce and Apex together to build a real app that you can use in Salesforce1 on a mobile device. |
|
|
|
We’ll start by finishing our mobile app that enables mobile technicians to quickly find nearby parts warehouses on their mobile phone. |
|
You’ll build a Visualforce page, write JavaScript that uses Visualforce’s JavaScript remoting to call your Apex method, retrieve the results, |
|
and then put them all on a map. Once that’s done, you’ll package it up and deploy it in Salesforce1. You’re going to be surprised just |
|
how easy that is! |
|
|
|
When you’re finished with this section, you will have done the following. |
|
|
|
• Link a Visualforce page to back-end Apex code. |
|
|
|
• Call Apex methods and use the results on a Visualforce page. |
|
|
|
• Write Visualforce controllers and controller extensions using Apex. |
|
|
|
• Use Visualforce JavaScript remoting to call Apex code, and convert the results into data for display on the page. |
|
|
|
• Add an app you created to Salesforce1 for use by mobile users on their phone or tablet. |
|
|
|
Creating Location-Aware Visualforce Pages |
|
|
|
You wrote an Apex extension that returns warehouses that are close to a specific latitude and longitude. Now you need an interface for |
|
the user to call that query and display the results. |
|
|
|
As a reminder, here’s our scenario. You’re going to write a small app to give mobile technicians that work for the Acme Wireless |
|
organization a way to find nearby warehouses. For example, if the technician is out on a call and needs a part, they can use this page to |
|
look for warehouses within a 20-mile radius. For each warehouse, a map should display a pin along with the warehouse name, address, |
|
and phone number. |
|
|
|
There a many ways you could build this app, but to make a mobile-friendly and dynamic page we’re going to use the Google Maps API. |
|
The JavaScript required to access the API and render maps has already been included in the Enhanced Warehouse as a static resource. |
|
We just need to create the page that loads the data and displays the map. |
|
|
|
Create a Visualforce Page Linked to the WarehouseUtils Class |
|
|
|
The first thing to do is create a new Visualforce page and then connect it with the server-side Apex logic. You’ll be connecting the |
|
Standard List Controller and an extension to the page. |
|
|
|
Because we want to deploy this page in Salesforce1, we need to edit a setting to mobile enable the page. This setting is only available |
|
in the Setup editor for Visualforce. |
|
|
|
1. From Setup, click Develop > Pages. |
|
|
|
2. Click New. |
|
|
|
3. For the Label and Name enter FindNearbyWarehouses. |
|
|
|
4. Select the checkbox for Available for Salesforce mobile apps. |
|
|
|
46 |
|
|
|
Visualforce and Apex In Action |
|
|
|
Add Static Resources to the Page |
|
|
|
5. |
|
|
|
In the code editor, replace the generated code with the following. |
|
|
|
<apex:page sidebar="false" showheader="false" |
|
|
|
standardController="Warehouse__c" recordSetVar="warehouses" |
|
extensions="WarehouseUtils"> |
|
|
|
<!-- resources and styles go here --> |
|
|
|
<!-- JavaScript custom code goes here --> |
|
|
|
<!-- Google Maps target [div] goes here --> |
|
|
|
</apex:page> |
|
|
|
6. Click Quick Save. |
|
|
|
Now that the page is created and enabled for mobile apps, you can switch to the Developer Console or Development Mode footer to |
|
continue editing the page. By now you may have a preference, so use whichever tool works best for you. |
|
|
|
Add Static Resources to the Page |
|
|
|
You’ve created the page shell, but before you start writing any JavaScript you’ll need to add a reference to several resources the page |
|
will use. |
|
|
|
These are stored as static resources in Salesforce, and can be associated with the page using the <apex:includeScript> |
|
component. This component makes sure that JavaScript libraries are included in the rendered HTML’s header properly. You’re also going |
|
to add a small amount of CSS to the page in order to display a full-width version of the map. |
|
|
|
1. |
|
|
|
Inside the <apex:page> component replace the comment line <!-- resources and styles go here --> with |
|
the following code. |
|
|
|
<!-- Include in Google's Maps API via JavaScript static resource. |
|
This is for development convenience, not production use. |
|
See next comment. --> |
|
|
|
<apex:includeScript value="{!$Resource.GoogleMapsAPI}" /> |
|
|
|
<!-- Set YOUR_API_KEY to fix JavaScript errors in production. See |
|
|
|
https://developers.google.com/maps/documentation/javascript/tutorial |
|
for details of how to obtain a Google Maps API key. --> |
|
|
|
<!-- <script type="text/javascript" |
|
|
|
src="https://maps.googleapis.com/maps/api/js?key=YOUR_API_KEY&sensor=false"> |
|
</script> --> |
|
|
|
<!-- Set the map to take up the whole window --> |
|
<style> |
|
|
|
html, body { height: 100%; } |
|
.page-map, .ui-content, #map-canvas { width: 100%; height:100%; padding: 0; } |
|
#map-canvas { height: min-height: 100%; } |
|
|
|
</style> |
|
|
|
2. Click Quick Save. |
|
|
|
47 |
|
|
|
Visualforce and Apex In Action |
|
|
|
Add a Place to Display the Map |
|
|
|
The code you’ve just added references the Google Maps API two different ways. One of them is commented out. The active version is |
|
the one included in the static resource, which will work in development. When you’re ready to develop a mapping app for real, you’ll |
|
want to get a Google Maps API key of your own, and replace the YOUR_API_KEY string with your real key. Then uncomment that |
|
<script> tag, and comment out or delete the <apex:includeScript> component. |
|
|
|
More details about the Google Maps API can be found in the Google Maps JavaScript API Getting Started guide. |
|
|
|
Add a Place to Display the Map |
|
|
|
The Google Maps API needs an HTML <div> tag “target” to know where to render the graphics. |
|
|
|
The Google Maps API renders the map and then inserts it into your page at a place you specify. So, you need to create that placeholder. |
|
|
|
1. |
|
|
|
Just before the closing </apex:page> tag, replace the comment line <!-- Google Maps target [div] goes |
|
here --> with the following code. |
|
|
|
<!-- All content is rendered by the Google Maps code |
|
|
|
This minimal HTML just provides a target for GMaps to write to --> |
|
|
|
<body style="font-family: Arial; border: 0 none;"> |
|
|
|
<div id="map-canvas"></div> |
|
|
|
</body> |
|
|
|
2. Click Quick Save. |
|
|
|
That completes the markup for the page. From here on, it’s JavaScript and JavaScript remoting. |
|
|
|
Add JavaScript to Query for Warehouses |
|
|
|
Now our page is ready for some JavaScript to make it work. You’ll start with a function that gets called when the page loads. This function |
|
calls the Apex Remote Action method that you created earlier, retrieving a list of warehouses to display. |
|
|
|
The code you’re about to add is written in JavaScript, but it’s using the Visualforce framework behind the scenes. This facility is called |
|
JavaScript remoting, and it’s a terrific way to combine Visualforce with dynamic, interactive pages built with JavaScript. |
|
|
|
1. After the <style> tag, replace the comment line <!-- JavaScript custom code goes here --> with the |
|
|
|
following code. |
|
|
|
<script> |
|
|
|
function initialize() { |
|
|
|
var lat, lon; |
|
|
|
// If we can, get the position of the user via device geolocation |
|
if (navigator.geolocation) { |
|
|
|
navigator.geolocation.getCurrentPosition(function(position){ |
|
|
|
lat = position.coords.latitude; |
|
lon = position.coords.longitude; |
|
|
|
// Use Visualforce JS Remoting to query for nearby warehouses |
|
Visualforce.remoting.Manager.invokeAction( |
|
|
|
'{!$RemoteAction.WarehouseUtils.findNearbyWarehouses}', |
|
lat, lon, |
|
function(result, event){ |
|
|
|
if (event.status) { |
|
|
|
console.log(result); |
|
|
|
48 |
|
|
|
Visualforce and Apex In Action |
|
|
|
Add JavaScript to Build the Map |
|
|
|
createMap(lat, lon, result); |
|
|
|
} else if (event.type === 'exception') { |
|
|
|
//exception case code |
|
|
|
} else { |
|
|
|
} |
|
|
|
}, |
|
{escape: true} |
|
|
|
); |
|
|
|
}); |
|
|
|
} else { |
|
|
|
// Set default values for the map if the device |
|
// doesn't have geolocation capabilities. |
|
// This is San Francisco: |
|
lat = 37.77493; |
|
lon = -122.419416; |
|
|
|
var result = []; |
|
createMap(lat, lon, result); |
|
|
|
} |
|
|
|
} |
|
|
|
// createMap function goes here |
|
|
|
</script> |
|
|
|
2. Click Quick Save. |
|
|
|
The JavaScript function you added does three things. |
|
|
|
• First, it uses the navigator.geolocation feature in JavaScript to ask the hardware device if it can provide geolocation |
|
coordinates. When this code runs, the user will be prompted by their device, requesting permission to share their location. |
|
|
|
• Second, if the device query is successful, Visualforce JavaScript remoting is used to call your Remote Action method. You can see it |
|
referenced right there in the code, {!$RemoteAction.WarehouseUtils.findNearbyWarehouses}, followed by |
|
the latitude and longitude parameters the Remote Action expects. How easy—how cool—is that? |
|
|
|
• Finally, if the device query fails—perhaps the user denied permission to share their location—a default location is defined instead. |
|
|
|
(Once again, it’s San Francisco, home of Salesforce.com.) |
|
|
|
Add JavaScript to Build the Map |
|
|
|
Now that your code has queried for and retrieved a collection of nearby warehouses, all that’s left is to convert the raw data into a map. |
|
|
|
You might have noticed in the code from the previous step that there are a few references to a createMap function. You’ll add that |
|
next. |
|
|
|
1. Before the end </script> tag, replace the comment line // createMap function goes here with the following |
|
|
|
code. |
|
|
|
function createMap(lat, lon, warehouses){ |
|
|
|
// Get the map div, and center the map at the proper geolocation |
|
var currentPosition = new google.maps.LatLng(lat,lon); |
|
var mapDiv = document.getElementById('map-canvas'); |
|
var map = new google.maps.Map(mapDiv, { |
|
|
|
center: currentPosition, |
|
|
|
49 |
|
|
|
Visualforce and Apex In Action |
|
|
|
Add JavaScript to Add Warehouse Markers to the Map |
|
|
|
zoom: 13, |
|
mapTypeId: google.maps.MapTypeId.ROADMAP |
|
|
|
}); |
|
|
|
// Set a marker for the current location |
|
var positionMarker = new google.maps.Marker({ |
|
|
|
map: map, |
|
position: currentPosition, |
|
icon: 'https://maps.google.com/mapfiles/ms/micons/green.png' |
|
|
|
}); |
|
|
|
// Keep track of the map boundary that holds all markers |
|
var mapBoundary = new google.maps.LatLngBounds(); |
|
mapBoundary.extend(currentPosition); |
|
|
|
// Set markers on the map from the @RemoteAction results |
|
var warehouse; |
|
for(var i=0; i<warehouses.length ; i++) { |
|
|
|
warehouse = warehouses[i]; |
|
console.log(warehouses[i]); |
|
setupMarker(); |
|
|
|
} |
|
|
|
// Resize map to neatly fit all of the markers |
|
map.fitBounds(mapBoundary); |
|
|
|
// setupMarker function goes here |
|
|
|
} |
|
|
|
2. Click Quick Save. |
|
|
|
This function receives a latitude and longitude for the center of the map—the user’s location—and the results of the query. It creates |
|
a new Google Map centered as expected, and then iterates over the results, adding them to the map using the setupMarker function. |
|
If you haven’t already guessed, that’s the next (and final!) step. |
|
|
|
Add JavaScript to Add Warehouse Markers to the Map |
|
|
|
The page is nearly complete. Your JavaScript is calling into Apex, getting a list of nearby warehouses, and then using Google to create |
|
a map of your current location. Now you just need to put the result markers onto the map. |
|
|
|
At the end of the last code snippet you saw a call to the setupMarker function, made while iterating through the found warehouses. |
|
Here’s the code for that function. |
|
|
|
1. Under the map.fitBounds() function call and before the end bracket, replace the comment line // setupMarker |
|
|
|
function goes here with the following code. |
|
|
|
function setupMarker(){ |
|
|
|
var warehouseNavUrl; |
|
|
|
// Determine if we are in Salesforce1 and set navigation |
|
// link appropriately |
|
try{ |
|
|
|
if(sforce.one){ |
|
|
|
warehouseNavUrl = |
|
|
|
50 |
|
|
|
Visualforce and Apex In Action |
|
|
|
Summary and Code Check |
|
|
|
'javascript:sforce.one.navigateToSObject(\'' + |
|
warehouse.Id + '\')'; |
|
|
|
} |
|
|
|
} catch(err) { |
|
|
|
console.log(err); |
|
warehouseNavUrl = '\\' + warehouse.Id; |
|
|
|
} |
|
|
|
var warehouseDetails = |
|
|
|
'<a href="' + warehouseNavUrl + '">' + |
|
warehouse.Name + '</a><br/>' + |
|
warehouse.Street_Address__c + '<br/>' + |
|
warehouse.City__c + '<br/>' + |
|
warehouse.Phone__c; |
|
|
|
// Create a panel that appears when the user clicks on the marker |
|
var infowindow = new google.maps.InfoWindow({ |
|
|
|
content: warehouseDetails |
|
|
|
}); |
|
|
|
// Add the marker to the map |
|
var marker = new google.maps.Marker({ |
|
|
|
map: map, |
|
position: new google.maps.LatLng( |
|
|
|
warehouse.Location__Latitude__s, |
|
warehouse.Location__Longitude__s) |
|
|
|
}); |
|
mapBoundary.extend(marker.getPosition()); |
|
|
|
// Add the action to open the panel when its marker is clicked |
|
google.maps.event.addListener(marker, 'click', function(){ |
|
|
|
infowindow.open(map, marker); |
|
|
|
}); |
|
|
|
} |
|
|
|
// page initialization goes here |
|
|
|
2. Finally, just below that method replace the comment line // page initialization goes here with the following |
|
|
|
code. |
|
|
|
// Fire the initialize function when the window loads |
|
google.maps.event.addDomListener(window, 'load', initialize); |
|
|
|
3. Click Quick Save. |
|
|
|
And with that you should have a map! |
|
|
|
Note: The warehouses in the sample data we provided are all located in the San Francisco area. If you’re testing the page from |
|
another location, be sure to add a few warehouses located within 20 miles of your location. |
|
|
|
Summary and Code Check |
|
|
|
You should be able to test the page now by going to your instance URL in your browser (for example, |
|
https://na15.salesforce.com/) and appending /apex/FindNearbyWarehouses. |
|
|
|
51 |
|
|
|
Visualforce and Apex In Action |
|
|
|
Summary and Code Check |
|
|
|
The final page is a lot of JavaScript and a bit of HTML. The standard Visualforce is minimal, but all of the data access was performed |
|
through the Visualforce framework using JavaScript remoting. |
|
|
|
Here’s the entire page if you’re not seeing a map in your final version. |
|
|
|
<apex:page sidebar="false" showheader="false" |
|
|
|
standardController="Warehouse__c" recordSetVar="warehouses" |
|
extensions="WarehouseUtils"> |
|
|
|
<!-- Include in Google's Maps API via JavaScript static resource. |
|
This is for development convenience, not production use. |
|
See next comment. --> |
|
|
|
<apex:includeScript value="{!$Resource.GoogleMapsAPI}" /> |
|
|
|
<!-- Set YOUR_API_KEY to fix JavaScript errors in production. See |
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https://developers.google.com/maps/documentation/javascript/tutorial |
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for details of how to obtain a Google Maps API key. --> |
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<!-- <script type="text/javascript" |
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src="https://maps.googleapis.com/maps/api/js?key=YOUR_API_KEY&sensor=false"> |
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</script> --> |
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<!-- Set the map to take up the whole window --> |
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<style> |
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html, body { height: 100%; } |
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.page-map, .ui-content, #map-canvas { width: 100%; height:100%; padding: 0; } |
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#map-canvas { height: min-height: 100%; } |
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</style> |
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<script> |
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function initialize() { |
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var lat, lon; |
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// If we can, get the position of the user via device geolocation |
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if (navigator.geolocation) { |
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navigator.geolocation.getCurrentPosition(function(position){ |
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lat = position.coords.latitude; |
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lon = position.coords.longitude; |
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// Use Visualforce JS Remoting to query for nearby warehouses |
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Visualforce.remoting.Manager.invokeAction( |
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'{!$RemoteAction.WarehouseUtils.findNearbyWarehouses}', |
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lat, lon, |
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function(result, event){ |
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if (event.status) { |
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console.log(result); |
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createMap(lat, lon, result); |
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} else if (event.type === 'exception') { |
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//exception case code |
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} else { |
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} |
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}, |
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{escape: true} |
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); |
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}); |
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52 |
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Visualforce and Apex In Action |
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Summary and Code Check |
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} else { |
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// Set default values for the map if the device |
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// doesn't have geolocation capabilities. |
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// This is San Francisco: |
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lat = 37.77493; |
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lon = -122.419416; |
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var result = []; |
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createMap(lat, lon, result); |
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} |
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} |
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function createMap(lat, lon, warehouses){ |
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// Get the map div, and center the map at the proper geolocation |
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var currentPosition = new google.maps.LatLng(lat,lon); |
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var mapDiv = document.getElementById('map-canvas'); |
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var map = new google.maps.Map(mapDiv, { |
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center: currentPosition, |
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zoom: 13, |
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mapTypeId: google.maps.MapTypeId.ROADMAP |
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}); |
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// Set a marker for the current location |
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var positionMarker = new google.maps.Marker({ |
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map: map, |
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position: currentPosition, |
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icon: 'https://maps.google.com/mapfiles/ms/micons/green.png' |
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}); |
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// Keep track of the map boundary that holds all markers |
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var mapBoundary = new google.maps.LatLngBounds(); |
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mapBoundary.extend(currentPosition); |
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// Set markers on the map from the @RemoteAction results |
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var warehouse; |
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for(var i=0; i<warehouses.length ; i++) { |
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warehouse = warehouses[i]; |
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console.log(warehouses[i]); |
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setupMarker(); |
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} |
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// Resize map to neatly fit all of the markers |
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map.fitBounds(mapBoundary); |
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function setupMarker(){ |
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var warehouseNavUrl; |
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// Determine if we are in Salesforce1 and set navigation |
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// link appropriately |
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try{ |
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if(sforce.one){ |
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warehouseNavUrl = |
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'javascript:sforce.one.navigateToSObject(\'' + |
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warehouse.Id + '\')'; |
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53 |
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Visualforce and Apex In Action |
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Add the Nearby Warehouses Page to Salesforce1 |
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} |
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} catch(err) { |
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console.log(err); |
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warehouseNavUrl = '\\' + warehouse.Id; |
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} |
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var warehouseDetails = |
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'<a href="' + warehouseNavUrl + '">' + |
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warehouse.Name + '</a><br/>' + |
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warehouse.Street_Address__c + '<br/>' + |
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warehouse.City__c + '<br/>' + |
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warehouse.Phone__c; |
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// Create a panel that appears when the user clicks on the marker |
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var infowindow = new google.maps.InfoWindow({ |
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content: warehouseDetails |
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}); |
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// Add the marker to the map |
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var marker = new google.maps.Marker({ |
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map: map, |
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position: new google.maps.LatLng( |
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warehouse.Location__Latitude__s, |
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warehouse.Location__Longitude__s) |
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}); |
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mapBoundary.extend(marker.getPosition()); |
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// Add the action to open the panel when its marker is clicked |
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google.maps.event.addListener(marker, 'click', function(){ |
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infowindow.open(map, marker); |
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}); |
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} |
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} |
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// Fire the initialize function when the window loads |
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google.maps.event.addDomListener(window, 'load', initialize); |
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</script> |
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<!-- All content is rendered by the Google Maps code |
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This minimal HTML just provides a target for GMaps to write to --> |
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<body style="font-family: Arial; border: 0 none;"> |
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<div id="map-canvas"></div> |
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</body> |
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</apex:page> |
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|
Now that it’s working in development, how about adding it to Salesforce1? Onward! |
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|
Add the Nearby Warehouses Page to Salesforce1 |
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|
Now that you have a working nearby warehouses page, you can add it to the mobile app. |
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54 |
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|
Visualforce and Apex In Action |
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|
Create a Tab for the Page |
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There are two steps. First, create a tab to hold the page and make it available in the Salesforce user interface. Second, add the tab to the |
|
Salesforce1 navigation menu. |
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Create a Tab for the Page |
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|
Visualforce pages are added to the Salesforce user interface by creating tabs to hold them. |
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Although we as developers get used to accessing our Visualforce pages using the direct URL, that’s not the way our users reach them |
|
day to day. Instead, they want to have the pages be accessible from the standard Salesforce user interface. The way you accomplish this |
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is by first creating a new tab to hold the page. |
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1. From Setup, click Create > Tabs. |
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2. |
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3. |
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4. |
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|
In the Visualforce Tabs section, click New. |
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In the Visualforce Page drop-down list, select FindNearbyWarehouses. |
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In the Tab Label field, enter Nearby Warehouses. |
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The label field is what users see both on the full site and in the mobile app. With that in mind, keep your labels concise. |
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5. Click into the Tab Style field, and select the Globe style. |
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The icon for this style appears as the icon for the page in the Salesforce1 mobile app’s navigation menu. |
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6. Click Next, and Next again. |
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7. Deselect the Include Tab checkbox so that the tab isn’t included in any of the apps in the desktop version of the site. You only want |
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this tab to appear when users are viewing Salesforce1 on their mobile device. |
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8. Click Save. |
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Add the Tab to Mobile Navigation |
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|
Now that you’ve created a tab to hold your Visualforce page, you’re ready to add the new tab to the Salesforce1 navigation menu. |
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In this step you add the tab as a navigation menu item in the Salesforce1 mobile app. The menu item will become available to mobile |
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app users who have access to it. |
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|
1. From Setup, click Mobile Administration > Mobile Navigation. |
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|
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2. Move Nearby Warehouses to the Selected list and then Save. |
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|
Try Out the App |
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|
Your new mobile app is complete! Search for nearby warehouses on your device. |
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|
|
Being able to test your mobile pages inside your desktop browser is great during development. But now that the page is finished and |
|
added to Salesforce1, it’s important to test it out on the actual devices your users will be using it with. |
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|
|
1. Open the Salesforce1 app on your mobile device. Refresh the app by pulling down. |
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|
|
2. Tap |
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|
|
to access the navigation menu. |
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|
|
You should see Nearby Warehouses under the Apps section. |
|
|
|
Note: |
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|
|
• If you’re using the /one/one.app browser version, you may need to refresh the browser to see the page in the |
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|
|
navigation menu. |
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|
|
• If you’re using the installed mobile app, you may need to log out and log in again to see the change. |
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|
55 |
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|
|
Visualforce and Apex In Action |
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|
|
Try Out the App |
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|
|
3. Tap Nearby Warehouses. |
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|
|
4. Click OK when you see a prompt that asks to use your current location. |
|
A map that contains warehouse locations within 20 miles appears. |
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|
|
56 |
|
|
|
Visualforce and Apex In Action |
|
|
|
Summary |
|
|
|
Note: If you don’t receive a prompt to share your location, it might be related to your device settings. If that’s the case, the |
|
geographical area should default to San Francisco. Also, the warehouses in the package sample data are all located in the San |
|
Francisco area. If you’re testing this from another location, be sure to add a few warehouses located within 20 miles of your |
|
location. |
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|
|
Summary |
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|
|
And...that’s it! You can see how easy it is to make standard pages and tabs available to your mobile users. |
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|
|
Adding your apps to Salesforce1 is pretty much a point-and-click operation. |
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|
|
Visualforce Pages with Apex Controllers |
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|
|
As you learned earlier in this workbook, Visualforce includes standard controllers for every sObject available in your organization. They |
|
make it easy for you to create Visualforce pages that handle common features without writing any code beyond the Visualforce itself. |
|
For highly customized applications, Visualforce allows you to extend or replace the standard controller with your own Apex code. You |
|
can make Visualforce applications available only within your company, or publish them on the Web. |
|
|
|
In this tutorial, you’ll use Visualforce to create a simple store front page. The page will list products for sale, offer a simple shopping card, |
|
and the app and its back-end code will illustrate how Visualforce connects to a controller written in Apex. |
|
|
|
Displaying Product Data in a Visualforce Page |
|
|
|
In this lesson, you’ll extend your first Visualforce page to display a list of products for sale. Although this page might seem fairly simple, |
|
there’s a lot going on, and we’re going to move quickly so we can get to the Apex. |
|
|
|
1. |
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|
|
In your browser, open your product catalog page at https://<your-instance>.salesforce.com/apex/Catalog, |
|
and click Create Page Catalog to create the new page. Open the Page Editor, if it’s not already open. |
|
|
|
2. Modify your code to enable the Merchandise__c standard controller, by editing the <apex:page> tag. |
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|
|
<apex:page standardController="Merchandise__c"> |
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|
|
This connects your page to your Merchandise__c custom object, using a built-in controller that provides a lot of basic functionality, |
|
like reading, writing, and creating new Merchandise__c objects. |
|
|
|
3. Next, add the standard list controller definition by setting the recordSetVar attribute. |
|
|
|
<apex:page standardController="Merchandise__c" recordSetVar="products"> |
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|
|
This configures your controller to work with lists of Merchandise__c records all at once, for example, to display a list of products in |
|
your catalog. Exactly what we want to do! |
|
|
|
4. Click Save. You can also press CTRL+S, if you prefer to use the keyboard. |
|
|
|
The page reloads, and if the Merchandise tab is visible, it becomes selected. Otherwise you won’t notice any change on the page. |
|
However, because you’ve set the page to use a controller, and defined the variable products, the variable will be available to |
|
you in the body of the page, and it will represent a list of Merchandise__c records. |
|
|
|
5. Replace any code between the two <apex:page> tags with a page block that will soon hold the products list. |
|
|
|
<apex:pageBlock title="Our Products"> |
|
|
|
<apex:pageBlockSection> |
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|
|
57 |
|
|
|
Visualforce and Apex In Action |
|
|
|
Displaying Product Data in a Visualforce Page |
|
|
|
(Products Go Here) |
|
|
|
</apex:pageBlockSection> |
|
|
|
</apex:pageBlock> |
|
|
|
Note: From here we’ll assume that you’ll save your changes whenever you want to see how the latest code looks. |
|
|
|
6. |
|
|
|
It’s time to add the actual list of products. Select the (Products Go Here) placeholder and replace it with a |
|
<apex:pageBlockTable> component. |
|
|
|
7. Now you need to add some attributes to the pageBlockTable tag. The value attribute indicates which list of items the |
|
|
|
pageBlockTable component should iterate over. The var attribute assigns each item of that list, for one single iteration, to |
|
the pitem variable. Add these attributes to the tag. |
|
|
|
<apex:pageBlockTable value="{!products}" var="pitem"> |
|
|
|
8. Now you’re going to define each column, and determine where it gets its data by looking up the appropriate field in the pitem |
|
|
|
variable. Add the following code between the opening and closing pageBlockTable tags. |
|
|
|
<apex:pageBlockTable value="{!products}" var="pitem"> |
|
|
|
<apex:column headerValue="Product"> |
|
|
|
<apex:outputText value="{!pitem.Name}"/> |
|
|
|
</apex:column> |
|
</apex:pageBlockTable> |
|
|
|
9. Click Save and you’ll see your product list appear. |
|
|
|
The headerValue attribute has simply provided a header title for the column, and below it you’ll see a list of rows, one for each |
|
merchandise record. The expression {!pitem.Name} indicates that we want to display the Name field of the current row. |
|
|
|
10. Now, after the closing tag for the first column, add two more columns. |
|
|
|
<apex:column headerValue="Condition"> |
|
|
|
<apex:outputField value="{!pitem.Condition__c}"/> |
|
|
|
</apex:column> |
|
<apex:column headerValue="Price"> |
|
|
|
<apex:outputField value="{!pitem.Price__c}"/> |
|
|
|
</apex:column> |
|
|
|
58 |
|
|
|
Visualforce and Apex In Action |
|
|
|
Using a Custom Apex Controller with a Visualforce Page |
|
|
|
11. With three columns, the listing is compressed because the table is narrow. Make it wider by changing the |
|
|
|
<apex:pageBlockSection> tag. |
|
|
|
<apex:pageBlockSection columns="1"> |
|
|
|
This changes the section from two columns to one, letting the single column be wider. |
|
|
|
12. Your code will look like this. |
|
|
|
<apex:page standardController="Merchandise__c" recordSetVar="products"> |
|
|
|
<apex:pageBlock title="Our Products"> |
|
|
|
<apex:pageBlockSection columns="1"> |
|
|
|
<apex:pageBlockTable value="{!products}" var="pitem"> |
|
|
|
<apex:column headerValue="Product"> |
|
|
|
<apex:outputText value="{!pitem.Name}"/> |
|
|
|
</apex:column> |
|
<apex:column headerValue="Condition"> |
|
|
|
<apex:outputField value="{!pitem.Condition__c}"/> |
|
|
|
</apex:column> |
|
<apex:column headerValue="Price"> |
|
|
|
<apex:outputField value="{!pitem.Price__c}"/> |
|
|
|
</apex:column> |
|
</apex:pageBlockTable> |
|
|
|
</apex:pageBlockSection> |
|
|
|
</apex:pageBlock> |
|
|
|
</apex:page> |
|
|
|
And there you have your product catalog! |
|
|
|
Tell Me More... |
|
|
|
• The pageBlockTable component produces a table with rows, and each row is found by iterating over a list. The standard |
|
controller you used for this page was set to Merchandise__c, and the recordSetVar to products. As a result, the |
|
controller automatically populated the products list variable with merchandise records retrieved from the database. It’s this list that |
|
the pageBlockTable component uses. |
|
|
|
• You need a way to reference the current record as you iterate over the list. The statement var="pitem" assigns a variable called |
|
|
|
pitem that holds the record for the current row. |
|
|
|
Using a Custom Apex Controller with a Visualforce Page |
|
|
|
You now have a Visualforce page that displays all of your merchandise records. Instead of using the default controller, as you did in the |
|
previous tutorial, you’re going to write the controller code yourself. Controllers typically retrieve the data to be displayed in a Visualforce |
|
page, and contain code that will be executed in response to page actions, such as a command button being clicked. |
|
|
|
In this lesson, you’ll convert the page from using a standard controller to using your own custom Apex controller. Writing a controller |
|
using Apex allows you to go beyond the basic behaviors provided by the standard controller. In the next lesson you’ll expand this |
|
controller and add some e-commerce features to change the listing into an online store. |
|
|
|
To create the new controller class: |
|
|
|
59 |
|
|
|
Visualforce and Apex In Action |
|
|
|
Using a Custom Apex Controller with a Visualforce Page |
|
|
|
1. From Setup, click Develop > Apex Classes. |
|
|
|
2. Click New. |
|
|
|
3. Add the following code as the definition of the class and then click Quick Save. |
|
|
|
public class StoreFrontController { |
|
|
|
List<Merchandise__c> products; |
|
|
|
public List<Merchandise__c> getProducts() { |
|
|
|
if(products == null) { |
|
|
|
products = [SELECT Id, Name, Condition__c, Price__c FROM Merchandise__c]; |
|
|
|
} |
|
return products; |
|
|
|
} |
|
|
|
} |
|
|
|
4. Navigate back to your product catalog page at https://<your-instance>.salesforce.com/apex/Catalog, |
|
|
|
and open the Page Editor, if it’s not already open. |
|
|
|
5. Change the opening <apex:page> tag to link your page to your new controller class. |
|
|
|
<apex:page controller="StoreFrontController"> |
|
|
|
Notice that the attribute name has changed from standardController to controller. You also remove the |
|
recordSetVar attribute, because it’s only used with standard controllers. |
|
|
|
6. Click Save to save your changes and reload the page. |
|
|
|
The only change you should see is that the Merchandise tab is no longer selected. |
|
|
|
7. Make the following addition to set the application tab style back to Merchandise. |
|
|
|
<apex:page controller="StoreFrontController" tabStyle="Merchandise__c"> |
|
|
|
8. Notice that above the Page Editor tool bar there is now a StoreFrontController button. Click it to view and edit your page’s controller |
|
|
|
code. Click Catalog to return to the Visualforce page code. |
|
|
|
You’ll use this in the next lessons. |
|
|
|
Tell Me More... |
|
|
|
• As in the previous lesson, the value attribute of the pageBlockTable is set to {!products}, indicating that the table |
|
|
|
component should iterate over a list called products. Because you are using a custom controller, when Visualforce evaluates the |
|
{!products}expression, it automatically looks for a method getProducts() in your Apex controller. |
|
|
|
60 |
|
|
|
Visualforce and Apex In Action |
|
|
|
Using Inner Classes in an Apex Controller |
|
|
|
• The StoreFrontController class does the bare minimum to provide the data required by the Visualforce catalog page. It |
|
contains that single method, getProducts(), which queries the database and returns a list of Merchandise__c records. |
|
|
|
• The combination of a public instance variable (here, products) with a getter method (getProducts()) to initialize and |
|
|
|
provide access to it is a common pattern in Visualforce controllers written in Apex. |
|
|
|
Using Inner Classes in an Apex Controller |
|
|
|
In the last lesson, you created a custom controller for your Visualforce catalog page. But your controller passes custom objects from the |
|
database directly to the view, which isn’t ideal. In this lesson, you’ll refactor your controller to more correctly use the MVC design pattern, |
|
and add some additional features to your page. |
|
|
|
1. Click StoreFrontController to edit your page’s controller code. |
|
|
|
2. Revise the definition of the class as follows and then click Quick Save. |
|
|
|
public class StoreFrontController { |
|
|
|
List<DisplayMerchandise> products; |
|
|
|
public List<DisplayMerchandise> getProducts() { |
|
|
|
if(products == null) { |
|
|
|
products = new List<DisplayMerchandise>(); |
|
for(Merchandise__c item : [ |
|
|
|
SELECT Id, Name, Description__c, Price__c, Total_Inventory__c |
|
FROM Merchandise__c]) { |
|
|
|
products.add(new DisplayMerchandise(item)); |
|
|
|
} |
|
|
|
} |
|
return products; |
|
|
|
} |
|
|
|
// Inner class to hold online store details for item |
|
public class DisplayMerchandise { |
|
|
|
private Merchandise__c merchandise; |
|
public DisplayMerchandise(Merchandise__c item) { |
|
|
|
this.merchandise = item; |
|
|
|
} |
|
|
|
// Properties for use in the Visualforce view |
|
public String name { |
|
|
|
get { return merchandise.Name; } |
|
|
|
} |
|
public String description { |
|
|
|
get { return merchandise.Description__c; } |
|
|
|
} |
|
public Decimal price { |
|
|
|
get { return merchandise.Price__c; } |
|
|
|
} |
|
public Boolean inStock { |
|
|
|
get { return (0 < merchandise.Total_Inventory__c); } |
|
|
|
} |
|
public Integer qtyToBuy { get; set; } |
|
|
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61 |
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Visualforce and Apex In Action |
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Using Inner Classes in an Apex Controller |
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} |
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} |
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3. Click Catalog to edit your page’s Visualforce code. |
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4. Change the column definitions to work with the property names of the new inner class. Replace the existing column definitions |
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with the following code. |
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<apex:column headerValue="Product"> |
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<apex:outputText value="{!pitem.Name}"/> |
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</apex:column> |
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<apex:column headerValue="Condition"> |
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<apex:outputText value="{!pitem.Condition}"/> |
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</apex:column> |
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<apex:column headerValue="Price"> |
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<apex:outputText value="{!pitem.Price}"/> |
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</apex:column> |
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The outputField component works automatically with sObject fields, but doesn’t work at all with custom classes. outputText |
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works with any value. |
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5. Click Save to save your changes and reload the page. |
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You’ll notice that the price column is no longer formatted as currency. |
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6. Change the price outputText tag to the following code. |
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<apex:outputText value="{0,number,currency}"> |
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<apex:param value="{!pitem.Price}"/> |
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</apex:outputText> |
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The outputText component can be used to automatically format different data types. |
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7. Verify that your code looks like the following and then click Save. |
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<apex:page controller="StoreFrontController" tabStyle="Merchandise__c"> |
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<apex:pageBlock title="Our Products"> |
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<apex:pageBlockSection columns="1"> |
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<apex:pageBlockTable value="{!products}" var="pitem"> |
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<apex:column headerValue="Product"> |
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<apex:outputText value="{!pitem.Name}"/> |
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</apex:column> |
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<apex:column headerValue="Condition"> |
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<apex:outputText value="{!pitem.Condition}"/> |
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</apex:column> |
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<apex:column headerValue="Price" style="text-align: right;"> |
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<apex:outputText value="{0,number,currency}"> |
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<apex:param value="{!pitem.Price}"/> |
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</apex:outputText> |
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</apex:column> |
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</apex:pageBlockTable> |
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</apex:pageBlockSection> |
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62 |
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Visualforce and Apex In Action |
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Adding Action Methods to an Apex Controller |
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</apex:pageBlock> |
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</apex:page> |
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Your catalog page will look something like this. |
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Tell Me More... |
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• The DisplayMerchandise class “wraps” the Merchandise__c type that you already have in the database, and adds new |
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properties and methods. The constructor lets you create a new DisplayMerchandise instance by passing in an existing |
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Merchandise__c record. The instance variable products is now defined as a list of DisplayMerchandise instances. |
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• The getProducts() method executes a query (the text within square brackets, also called a SOQL query) returning all |
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Merchandise__c records. It then iterates over the records returned by the query, adding them to a list of DisplayMerchandise |
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products, which is then returned. |
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Adding Action Methods to an Apex Controller |
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In this lesson, you’ll add action method to your controller to allow it to handle clicking a new Add to Cart button, as well as a new |
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method that outputs the contents of a shopping cart. You’ll see how Visualforce transparently passes data back to your controller where |
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it can be processed. On the Visualforce side you’ll add that button to the page, as well as form fields for shoppers to fill in. |
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1. Click StoreFrontController to edit your page’s controller code. |
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2. Add the following shopping cart code to the definition of StoreFrontController, immediately after the products |
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instance variable, and then click Quick Save. |
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List<DisplayMerchandise> shoppingCart = new List<DisplayMerchandise>(); |
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// Action method to handle purchasing process |
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public PageReference addToCart() { |
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for(DisplayMerchandise p : products) { |
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if(0 < p.qtyToBuy) { |
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shoppingCart.add(p); |
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} |
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} |
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return null; // stay on the same page |
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} |
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public String getCartContents() { |
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if(0 == shoppingCart.size()) { |
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return '(empty)'; |
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} |
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String msg = '<ul>\n'; |
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for(DisplayMerchandise p : shoppingCart) { |
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63 |
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Visualforce and Apex In Action |
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Adding Action Methods to an Apex Controller |
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msg += '<li>'; |
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msg += p.name + ' (' + p.qtyToBuy + ')'; |
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msg += '</li>\n'; |
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} |
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msg += '</ul>'; |
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return msg; |
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} |
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Now you’re ready to add a user interface for purchasing to your product catalog. |
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3. Click Catalog to edit your page’s Visualforce code. |
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4. Wrap the product catalog in a form tag, so that the page structure looks like this code. |
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<apex:page controller="StoreFrontController"> |
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<apex:form> |
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<!-- rest of page code --> |
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</apex:form> |
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</apex:page> |
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The <apex:form> component enables your page to send user-submitted data back to its controller. |
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5. Add a fourth column to the products listing table using this code. |
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<apex:column headerValue="Qty to Buy"> |
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<apex:inputText value="{!pitem.qtyToBuy}" rendered="{! pitem.inStock}"/> |
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<apex:outputText value="Out of Stock" rendered="{! NOT(pitem.inStock)}"/> |
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</apex:column> |
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This column will be a form field for entering a quantity to buy, or an out-of-stock notice, based on the value of the |
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DisplayMerchandise.inStock() method for each product. |
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6. Click Save and reload the page. |
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There’s a new column for customers to enter a number of units to buy for each product. |
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7. Add a shopping cart button by placing the following code just before the </apex:pageBlock> tag. |
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<apex:pageBlockSection> |
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<apex:commandButton action="{!addToCart}" value="Add to Cart"/> |
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</apex:pageBlockSection> |
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If you click Save and try the form now, everything works…except you can’t see any effect, because the shopping cart isn’t visible. |
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8. Add the following code to your page, right above the terminating </apex:form> tag. |
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<apex:pageBlock title="Your Cart" id="shopping_cart"> |
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<apex:outputText value="{!cartContents}" escape="false"/> |
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</apex:pageBlock> |
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9. Click Save, and give the form a try now. You should be able to add items to your shopping cart! In this case, it’s just a simple text |
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display. In a real-world scenario, you can imagine emailing the order, invoking a Web service, updating the database, and so on. |
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10. For a bonus effect, modify the code on the Add to Cart commandButton. |
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<apex:commandButton action="{!addToCart}" value="Add to Cart" reRender="shopping_cart"/> |
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If you click Save and use the form now, the shopping cart is updated via Ajax, instead of by reloading the page. |
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64 |
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Visualforce and Apex In Action |
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Summary |
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Tell Me More... |
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• As you saw in this lesson, Visualforce automatically mirrored the data changes on the form back to the products variable. This |
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functionality is extremely powerful, and lets you quickly build forms and other complex input pages. |
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• When you click the Add to Cart button, the shopping cart panel updates without updating the entire screen. The Ajax effect that |
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does this, which typically requires complex JavaScript manipulation, was accomplished with a simple reRender attribute. |
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• If you click Add to Cart multiple times with different values in the Qty to Buy fields, you’ll notice a bug, where products are duplicated |
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in the shopping cart. Knowing what you now know about Apex, can you find and fix the bug? One way might be to change a certain |
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List to a Map, so you can record and check for duplicate IDs. Where would you go to learn the necessary Map methods…? |
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Summary |
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In this tutorial, you created a custom user interface for your Warehouse application by writing a Visualforce page with an Apex controller |
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class. You saw how Visualforce pages can use the MVC design pattern, and how Apex classes fit into that pattern. And you saw how easy |
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it was to process submitted form data, manage app and session data, and add convenience methods using an inner class. |
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65 |
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CONCLUSION AND WHERE TO GO FROM HERE |
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Congratulations and thank you for finishing this workbook! Let’s take a look at what you learned, and where you might want to go next. |
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This workbook covered a lot of ground, and gives you a great start on becoming a true expert in Force.com development. |
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• You learned all about creating and editing Visualforce pages and Apex classes, including where to find them in Setup, and how to |
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edit them using multiple tools. |
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• You used a lot of different Visualforce components, and composed them together in multiple different ways. |
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• You tried several different ways to architect your Visualforce pages, using both standard Visualforce and JavaScript remoting. |
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• More importantly, you learned why you might want to use one approach or another to writing your Visualforce pages, depending |
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on where and how it will be used. |
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• You learned the basics of writing Apex, including creating classes, methods, and tests. |
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• You leveraged powerful Visualforce runtime features like the Standard Controller, and you wrote Apex code that can replace the |
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Standard Controller when the features it provides aren’t right for your app. |
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• And, most important of all, you hopefully got a taste for building your own custom apps on top of the Force.com Platform. |
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With powerful built-in functionality, flexible tools, and diverse deployment options, there’s a world of opportunity open to you as you |
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begin your career with Visualforce and Apex. You’ve learned a lot, but there’s a lot more available to you. |
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• First and most importantly, you can find every resource we offer for developers at https://developer.salesforce.com/. Bookmark it |
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right now! |
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• The next step in learning Visualforce is the Visualforce Developer’s Guide. It’s the definitive resource for learning everything about |
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|
Visualforce, and includes basic, intermediate, and advanced explanations and sample code. It also includes a complete reference to |
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the nearly 150 Visualforce components you can use in your pages and apps. If you’re thirsty for Visualforce, this is an almost bottomless |
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well. |
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• If the code in this book has whet your appetite to write it yourself, there are lots of ways to learn. If books are your thing, we like |
|
Head First Java. If you’d prefer a formal training class, consider enrolling in Introduction to Object-Oriented Programming with |
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Force.com Code (ADM231), a class designed specifically for Salesforce admins who want to learn to create software with Apex. |
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• To learn more Apex, your next step is the Apex Workbook. You’ve got a big head start on it, but the Apex Workbook offers a more |
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complete look at the language itself, and the many ways you can use it in addition to extending Visualforce. |
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• Like Visualforce, Apex has a great, in-depth Force.com Apex Code Developer’s Guide that covers the language in exhaustive detail. It |
|
includes a reference to the hundreds of built-in classes that provide higher-level abstractions and services to your application code. |
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• Salesforce1 is a great way to put your apps in the hands of your mobile users. The Salesforce1 App Developer Guide is a comprehensive |
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resource for that exciting platform. |
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• If you’re dreaming of selling your apps in the Salesforce AppExchange, the ISVforce Workbook is a quick introduction and the ISVforce |
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|
Guide is a complete reference to developing and distributing apps that leverage the Force.com platform. |
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And the list goes on. From blogs from our engineers and developer marketing team, to developer forums, to webinars and videos |
|
covering the very latest features, the Force.com Platform offers a rich ecosystem for learning about and building powerful cloud-based |
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applications. |
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66 |
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