ForceDotCom Apex Code Developers Guide - Meetup

679 Pages·2012·3.67 MB·English

salesforce: Winter ’13
Force.com Apex Code Developer's Guide
Last updated: December 7 2012
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Table of Contents
Table of Contents
Chapter 1: Introducing Apex...............................................................................................................11
What is Apex?.........................................................................................................................................................................12
How Does Apex Work?..............................................................................................................................................13
What is the Apex Development Process?....................................................................................................................14
Using a Developer or Sandbox Organization...................................................................................................14
Learning Apex.................................................................................................................................................17
Writing Apex...................................................................................................................................................18
Writing Tests...................................................................................................................................................19
Deploying Apex to a Sandbox Organization...................................................................................................19
Deploying Apex to a Salesforce Production Organization...............................................................................20
Adding Apex Code to a Force.com AppExchange App..................................................................................20
When Should I Use Apex?..........................................................................................................................................21
What are the Limitations of Apex?.............................................................................................................................21
What's New?...........................................................................................................................................................................22
Apex Quick Start.....................................................................................................................................................................22
Documentation Typographical Conventions...............................................................................................................22
Understanding Apex Core Concepts...........................................................................................................................23
Writing Your First Apex Class and Trigger................................................................................................................28
Creating a Custom Object...............................................................................................................................28
Adding an Apex Class.....................................................................................................................................29
Adding an Apex Trigger..................................................................................................................................30
Adding a Test Class.........................................................................................................................................31
Deploying Components to Production............................................................................................................33
Chapter 2: Language Constructs.........................................................................................................35
Data Types..............................................................................................................................................................................36
Primitive Data Types...................................................................................................................................................36
sObject Types..............................................................................................................................................................39
Accessing sObject Fields..................................................................................................................................40
Accessing sObject Fields Through Relationships............................................................................................41
Validating sObjects and Fields .......................................................................................................................42
Collections...................................................................................................................................................................43
Lists.................................................................................................................................................................43
Sets..................................................................................................................................................................48
Maps................................................................................................................................................................50
Parameterized Typing......................................................................................................................................51
Using Custom Types in Map Keys and Sets....................................................................................................51
Iterating Collections........................................................................................................................................54
Enums.........................................................................................................................................................................54
Understanding Rules of Conversion............................................................................................................................56
Variables..................................................................................................................................................................................57
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Case Sensitivity............................................................................................................................................................58
Constants.....................................................................................................................................................................58
Expressions..............................................................................................................................................................................59
Understanding Expressions.........................................................................................................................................59
Understanding Expression Operators..........................................................................................................................60
Understanding Operator Precedence...........................................................................................................................66
Extending sObject and List Expressions.....................................................................................................................66
Using Comments.........................................................................................................................................................67
Assignment Statements...........................................................................................................................................................67
Conditional (If-Else) Statements............................................................................................................................................68
Loops.......................................................................................................................................................................................69
Do-While Loops.........................................................................................................................................................69
While Loops................................................................................................................................................................70
For Loops....................................................................................................................................................................70
Traditional For Loops.....................................................................................................................................71
List or Set Iteration For Loops........................................................................................................................71
SOQL For Loops............................................................................................................................................72
SOQL and SOSL Queries......................................................................................................................................................73
Working with SOQL and SOSL Query Results.........................................................................................................75
Working with SOQL Aggregate Functions................................................................................................................76
Working with Very Large SOQL Queries..................................................................................................................76
Using SOQL Queries That Return One Record........................................................................................................79
Improving Performance by Not Searching on Null Values.........................................................................................79
Understanding Foreign Key and Parent-Child Relationship SOQL Queries.............................................................80
Working with Polymorphic Relationships in SOQL Queries.....................................................................................80
Using Apex Variables in SOQL and SOSL Queries...................................................................................................81
Querying All Records with a SOQL Statement..........................................................................................................83
Locking Statements.................................................................................................................................................................83
Locking in a SOQL For Loop....................................................................................................................................83
Avoiding Deadlocks....................................................................................................................................................84
Transaction Control................................................................................................................................................................84
Exception Statements..............................................................................................................................................................85
Throw Statements.......................................................................................................................................................85
Try-Catch-Finally Statements.....................................................................................................................................85
Chapter 3: Invoking Apex...................................................................................................................87
Triggers...................................................................................................................................................................................88
Bulk Triggers...............................................................................................................................................................89
Trigger Syntax.............................................................................................................................................................89
Trigger Context Variables...........................................................................................................................................90
Context Variable Considerations.................................................................................................................................92
Common Bulk Trigger Idioms....................................................................................................................................93
Using Maps and Sets in Bulk Triggers............................................................................................................93
Correlating Records with Query Results in Bulk Triggers..............................................................................94
Using Triggers to Insert or Update Records with Unique Fields.....................................................................94
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Defining Triggers........................................................................................................................................................94
Triggers and Merge Statements..................................................................................................................................96
Triggers and Recovered Records.................................................................................................................................97
Triggers and Order of Execution.................................................................................................................................97
Operations that Don't Invoke Triggers.......................................................................................................................99
Entity and Field Limitations in Triggers...................................................................................................................101
Trigger Exceptions....................................................................................................................................................101
Trigger and Bulk Request Best Practices...................................................................................................................102
Apex Scheduler......................................................................................................................................................................103
Anonymous Blocks................................................................................................................................................................108
Apex in AJAX.......................................................................................................................................................................109
Chapter 4: Classes, Objects, and Interfaces........................................................................................111
Understanding Classes..........................................................................................................................................................112
Defining Apex Classes...............................................................................................................................................112
Extended Class Example...........................................................................................................................................113
Declaring Class Variables..........................................................................................................................................116
Defining Class Methods............................................................................................................................................117
Using Constructors....................................................................................................................................................119
Access Modifiers........................................................................................................................................................121
Static and Instance.....................................................................................................................................................122
Using Static Methods and Variables..............................................................................................................122
Using Instance Methods and Variables..........................................................................................................123
Using Initialization Code...............................................................................................................................124
Apex Properties.........................................................................................................................................................125
Interfaces and Extending Classes..........................................................................................................................................127
Custom Iterators........................................................................................................................................................128
Keywords...............................................................................................................................................................................130
Using the final Keyword............................................................................................................................................131
Using the instanceof Keyword...................................................................................................................................131
Using the super Keyword...........................................................................................................................................131
Using the this Keyword.............................................................................................................................................132
Using the transient Keyword.....................................................................................................................................133
Using the with sharing or without sharing Keywords................................................................................................134
Annotations...........................................................................................................................................................................136
Deprecated Annotation.............................................................................................................................................137
Future Annotation.....................................................................................................................................................137
IsTest Annotation.....................................................................................................................................................138
ReadOnly Annotation...............................................................................................................................................141
RemoteAction Annotation........................................................................................................................................142
Apex REST Annotations..........................................................................................................................................142
RestResource Annotation..............................................................................................................................143
HttpDelete Annotation.................................................................................................................................143
HttpGet Annotation......................................................................................................................................144
HttpPatch Annotation...................................................................................................................................144
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HttpPost Annotation.....................................................................................................................................144
HttpPut Annotation......................................................................................................................................144
Classes and Casting...............................................................................................................................................................144
Classes and Collections.............................................................................................................................................146
Collection Casting.....................................................................................................................................................146
Differences Between Apex Classes and Java Classes.............................................................................................................146
Class Definition Creation......................................................................................................................................................147
Naming Conventions.................................................................................................................................................149
Name Shadowing......................................................................................................................................................149
Class Security........................................................................................................................................................................149
Enforcing Object and Field Permissions...............................................................................................................................150
Namespace Prefix..................................................................................................................................................................151
Using Namespaces When Invoking Methods...........................................................................................................152
Namespace, Class, and Variable Name Precedence...................................................................................................152
Type Resolution and System Namespace for Types..................................................................................................153
Version Settings....................................................................................................................................................................153
Setting the Salesforce API Version for Classes and Triggers....................................................................................154
Setting Package Versions for Apex Classes and Triggers..........................................................................................155
Chapter 5: Testing Apex...................................................................................................................156
Understanding Testing in Apex............................................................................................................................................157
Why Test Apex?........................................................................................................................................................157
What to Test in Apex................................................................................................................................................157
Unit Testing Apex.................................................................................................................................................................158
Isolation of Test Data from Organization Data in Unit Tests..................................................................................159
Using the runAs Method...........................................................................................................................................160
Using Limits, startTest, and stopTest.......................................................................................................................161
Adding SOSL Queries to Unit Tests........................................................................................................................162
Running Unit Test Methods.................................................................................................................................................163
Testing Best Practices...........................................................................................................................................................167
Testing Example...................................................................................................................................................................168
Chapter 6: Dynamic Apex.................................................................................................................173
Understanding Apex Describe Information..........................................................................................................................174
Dynamic SOQL....................................................................................................................................................................183
Dynamic SOSL.....................................................................................................................................................................183
Dynamic DML.....................................................................................................................................................................184
Chapter 7: Batch Apex......................................................................................................................187
Using Batch Apex..................................................................................................................................................................188
Understanding Apex Managed Sharing................................................................................................................................197
Understanding Sharing..............................................................................................................................................197
Sharing a Record Using Apex....................................................................................................................................199
Recalculating Apex Managed Sharing.......................................................................................................................204
Chapter 8: Debugging Apex..............................................................................................................209
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Understanding the Debug Log..............................................................................................................................................210
Working with Logs in the Developer Console..........................................................................................................214
Debugging Apex API Calls.......................................................................................................................................223
Handling Uncaught Exceptions............................................................................................................................................224
Understanding Execution Governors and Limits..................................................................................................................225
Using Governor Limit Email Warnings...............................................................................................................................230
Chapter 9: Developing Apex in Managed Packages............................................................................231
Package Versions...................................................................................................................................................................232
Deprecating Apex..................................................................................................................................................................232
Behavior in Package Versions................................................................................................................................................233
Versioning Apex Code Behavior...............................................................................................................................233
Apex Code Items that Are Not Versioned................................................................................................................234
Testing Behavior in Package Versions.......................................................................................................................235
Chapter 10: Exposing Apex Methods as SOAP Web Services..............................................................237
WebService Methods............................................................................................................................................................238
Exposing Data with WebService Methods................................................................................................................238
Considerations for Using the WebService Keyword..................................................................................................238
Overloading Web Service Methods...........................................................................................................................240
Chapter 11: Exposing Apex Classes as REST Web Services................................................................241
Introduction to Apex REST..................................................................................................................................................242
Apex REST Annotations......................................................................................................................................................242
Apex REST Methods............................................................................................................................................................242
Exposing Data with Apex REST Web Service Methods......................................................................................................247
Apex REST Code Samples...................................................................................................................................................248
Apex REST Basic Code Sample...............................................................................................................................248
Apex REST Code Sample Using RestRequest.........................................................................................................249
Chapter 12: Invoking Callouts Using Apex........................................................................................251
Adding Remote Site Settings................................................................................................................................................252
SOAP Services: Defining a Class from a WSDL Document...............................................................................................252
Invoking an External Service.....................................................................................................................................253
HTTP Header Support.............................................................................................................................................253
Supported WSDL Features.......................................................................................................................................254
Understanding the Generated Code..........................................................................................................................257
Testing Web Service Callouts...................................................................................................................................259
Considerations Using WSDLs..................................................................................................................................261
Mapping Headers..........................................................................................................................................261
Understanding Runtime Events.....................................................................................................................262
Understanding Unsupported Characters in Variable Names.........................................................................262
Debugging Classes Generated from WSDL Files.........................................................................................262
Invoking HTTP Callouts......................................................................................................................................................262
Using Certificates..................................................................................................................................................................263
Generating Certificates..............................................................................................................................................263
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Using Certificates with SOAP Services.....................................................................................................................264
Using Certificates with HTTP Requests...................................................................................................................265
Callout Limits and Limitations.............................................................................................................................................265
Chapter 13: Reference.......................................................................................................................267
Apex Data Manipulation Language (DML) Operations......................................................................................................268
ConvertLead Operation............................................................................................................................................269
Delete Operation.......................................................................................................................................................272
Insert Operation........................................................................................................................................................274
Merge Statement.......................................................................................................................................................277
Undelete Operation...................................................................................................................................................278
Update Operation......................................................................................................................................................280
Upsert Operation.......................................................................................................................................................282
sObjects That Do Not Support DML Operations....................................................................................................286
sObjects That Cannot Be Used Together in DML Operations................................................................................287
Bulk DML Exception Handling...............................................................................................................................289
Apex Standard Classes and Methods....................................................................................................................................289
Apex Primitive Methods...........................................................................................................................................290
Blob Methods................................................................................................................................................290
Boolean Methods...........................................................................................................................................291
Date Methods................................................................................................................................................291
Datetime Methods.........................................................................................................................................294
Decimal Methods..........................................................................................................................................299
Double Methods............................................................................................................................................304
ID Methods...................................................................................................................................................306
Integer Methods............................................................................................................................................307
Long Methods...............................................................................................................................................308
String Methods..............................................................................................................................................308
Time Methods...............................................................................................................................................332
Apex Collection Methods..........................................................................................................................................333
List Methods.................................................................................................................................................333
Map Methods................................................................................................................................................340
Set Methods...................................................................................................................................................344
Enum Methods.........................................................................................................................................................347
Apex sObject Methods..............................................................................................................................................348
Schema Methods...........................................................................................................................................348
sObject Methods............................................................................................................................................352
sObject Describe Result Methods.................................................................................................................357
Describe Field Result Methods.....................................................................................................................361
Schema.FieldSet Methods.............................................................................................................................369
Custom Settings Methods.............................................................................................................................372
Apex System Methods...............................................................................................................................................380
ApexPages Methods......................................................................................................................................380
Approval Methods.........................................................................................................................................381
Database Methods.........................................................................................................................................382
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JSON Support...............................................................................................................................................396
Limits Methods.............................................................................................................................................413
Math Methods...............................................................................................................................................416
MultiStaticResourceCalloutMock Methods..................................................................................................421
Apex REST...................................................................................................................................................421
Search Methods.............................................................................................................................................427
StaticResourceCalloutMock Methods...........................................................................................................427
System Methods............................................................................................................................................428
Test Methods.................................................................................................................................................439
Type Methods...............................................................................................................................................444
URL Methods...............................................................................................................................................448
UserInfo Methods..........................................................................................................................................451
Version Methods...........................................................................................................................................452
Using Exception Methods.........................................................................................................................................454
Apex Classes..........................................................................................................................................................................457
Apex Email Classes...................................................................................................................................................457
Outbound Email............................................................................................................................................457
Inbound Email...............................................................................................................................................469
Exception Class.........................................................................................................................................................474
Constructing an Exception............................................................................................................................475
Using Exception Variables.............................................................................................................................476
Visualforce Classes.....................................................................................................................................................476
Action Class...................................................................................................................................................477
Dynamic Component Methods and Properties.............................................................................................478
IdeaStandardController Class........................................................................................................................479
IdeaStandardSetController Class...................................................................................................................482
KnowledgeArticleVersionStandardController Class......................................................................................486
Message Class................................................................................................................................................489
PageReference Class......................................................................................................................................490
SelectOption Class.........................................................................................................................................496
StandardController Class...............................................................................................................................498
StandardSetController Class..........................................................................................................................500
Flow.Interview Class.................................................................................................................................................503
Pattern and Matcher Classes.....................................................................................................................................504
Using Patterns and Matchers.........................................................................................................................504
Using Regions................................................................................................................................................505
Using Match Operations...............................................................................................................................505
Using Bounds................................................................................................................................................506
Understanding Capturing Groups.................................................................................................................506
Pattern and Matcher Example.......................................................................................................................506
Pattern Methods............................................................................................................................................507
Matcher Methods..........................................................................................................................................509
HTTP (RESTful) Services Classes...........................................................................................................................514
HTTP Classes...............................................................................................................................................515
Crypto Class..................................................................................................................................................525
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EncodingUtil Class........................................................................................................................................531
XML Classes.............................................................................................................................................................532
XmlStream Classes........................................................................................................................................532
DOM Classes................................................................................................................................................539
Apex Approval Processing Classes............................................................................................................................545
Apex Approval Processing Example..............................................................................................................545
ProcessRequest Class.....................................................................................................................................546
ProcessResult Class........................................................................................................................................547
ProcessSubmitRequest Class.........................................................................................................................547
ProcessWorkitemRequest Class....................................................................................................................548
BusinessHours Class..................................................................................................................................................549
Apex Community Classes..........................................................................................................................................551
Answers Class................................................................................................................................................551
Ideas Class.....................................................................................................................................................552
Knowledge Management Publishing Service Class...................................................................................................555
Site Class...................................................................................................................................................................559
Cookie Class..............................................................................................................................................................565
Network Class...........................................................................................................................................................567
Apex Interfaces......................................................................................................................................................................567
Auth.RegistrationHandler Interface..........................................................................................................................569
Comparable Interface................................................................................................................................................572
HttpCalloutMock Interface.......................................................................................................................................574
InstallHandler Interface.............................................................................................................................................574
Support.EmailTemplateSelector Interface................................................................................................................576
Site.UrlRewriter Interface..........................................................................................................................................577
Using the Process.Plugin Interface............................................................................................................................584
Process.Plugin Interface.................................................................................................................................585
Process.PluginRequest Class..........................................................................................................................586
Process.PluginResult Class............................................................................................................................587
Process.PluginDescribeResult Class..............................................................................................................587
Process.Plugin Data Type Conversions.........................................................................................................590
Sample Process.Plugin Implementation for Lead Conversion.......................................................................590
UninstallHandler Interface........................................................................................................................................596
WebServiceMock Interface.......................................................................................................................................598
Chapter 14: Deploying Apex.............................................................................................................599
Using Change Sets To Deploy Apex.....................................................................................................................................600
Using the Force.com IDE to Deploy Apex...........................................................................................................................600
Using the Force.com Migration Tool....................................................................................................................................601
Understanding deploy................................................................................................................................................602
Understanding retrieveCode......................................................................................................................................604
Understanding runTests()..........................................................................................................................................605
Using SOAP API to Deploy Apex........................................................................................................................................606
Appendices......................................................................................................................................607
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