Book Image

Mastering Apex Programming

By : Paul Battisson
5 (1)
Book Image

Mastering Apex Programming

5 (1)
By: Paul Battisson

Overview of this book

As applications built on the Salesforce platform are now a key part of many organizations, developers are shifting focus to Apex, Salesforce’s proprietary programming language. As a Salesforce developer, it is important to understand the range of tools at your disposal, how and when to use them, and best practices for working with Apex. Mastering Apex Programming will help you explore the advanced features of Apex programming and guide you in delivering robust solutions that scale. This book starts by taking you through common Apex mistakes, debugging, exception handling, and testing. You'll then discover different asynchronous Apex programming options and develop custom Apex REST web services. The book shows you how to define and utilize Batch Apex, Queueable Apex, and Scheduled Apex using common scenarios before teaching you how to define, publish, and consume platform events and RESTful endpoints with Apex. Finally, you'll learn how to profile and improve the performance of your Apex application, including architecture trade-offs. With code examples used to facilitate discussion throughout, by the end of the book, you'll have developed the skills needed to build robust and scalable applications in Apex.
Table of Contents (21 chapters)
1
Section 1 – Triggers, Testing, and Security
8
Section 2 – Asynchronous Apex and Apex REST
15
Section 3 – Apex Performance

Defining Queueable Apex implementations

Queueable Apex, like Batch Apex, is defined through the implementation of an Apex interface, in this case, the Queueable interface.

To define a Queueable Apex job, we simply implement this interface, which has a single method, execute(QueueableContext context). A very basic implementation would then be the following:

public class ExampleQueueable implements Queueable {
	public void execute(QueueableContext context) {
		//Do something
	}
}

As we discussed, unlike our Batch Apex implementations, we must define the scope for the Queueable Apex job to process. We can do this in two ways. We can do it through the use of a query within our execute method:

public class ExampleQueueable implements Queueable {
    public void execute(QueueableContext context) {
          List<Account> accs = [SELECT Id, Name FROM Account        ...