Control Processes with Queueable Apex

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We took the simplicity of future methods and the power of Batch Apex and mixed them together to form Queueable Apex

 It gives you a class structure that the platform serializes for you, a simplified interface without start and finish methods and even allows you to utilize more than just primitive arguments

 simple System.enqueueJob() method, which returns a job ID that you can monitor

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Queueable Apex 的優點 

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@isTest
public class UpdateParentAccountTest {
    @testSetup 
    static void setup() {
        List<Account> accounts = new List<Account>();
        // add a parent account
        accounts.add(new Account(name='Parent'));
        // add 100 child accounts
        for (Integer i = 0; i < 100; i++) {
            accounts.add(new Account(
                name='Test Account'+i
            ));
        }
        insert accounts;
    }
    
    static testmethod void testQueueable() {
        // query for test data to pass to queueable class
        Id parentId = [select id from account where name = 'Parent'][0].Id;
        List<Account> accounts = [select id, name from account where name like 'Test Account%'];
        // Create our Queueable instance
        UpdateParentAccount updater = new UpdateParentAccount(accounts, parentId);
        // startTest/stopTest block to force async processes to run
        Test.startTest();        
        System.enqueueJob(updater);
        Test.stopTest();        
        // Validate the job ran. Check if record have correct parentId now
        System.assertEquals(100, [select count() from account where parentId = :parentId]);
    }
    
}

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Queueable Apex的最佳功能之一是作業鏈接。

如果您需要按順序運行作業，那麼Queueable Apex可以使您的生活更加輕鬆。

要將一個工作鏈接到另一個工作,submit the second job from the execute() method of your queueable class. 

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Create an Queueable Apex class that inserts Contacts for Accounts

AddPrimaryContact.apxc

public class AddPrimaryContact implements Queueable {
    
    private String st;
    private Contact primecontact;
    
    public AddPrimaryContact(Contact aContact, String aState) {
        this.st=aState;
        this.primecontact = aContact;
    }
    public void execute(QueueableContext context) {
        List<Account> accounts = [select name from account where billingstate=:st LIMIT 200];
        List<Contact> contacts = new List<Contact>();
        for (Account acc : accounts) {
            contact con=primecontact.clone(false,false,false,false);
            contacts.add(con);
        }
        insert contacts;
    }
}

AddPrimaryContactTest.apxc

@isTest
public class AddPrimaryContactTest {
    @testSetup 
    static void setup() {
        List<Account> accounts = new List<Account>();
        // add 50 NY account
        for (Integer i = 0; i < 50; i++) {
            accounts.add(new Account(Name='NY'+i, billingstate='NY'));
        }
        // add 50 CA account
        for (Integer j = 0; j < 50; j++) {
            accounts.add(new Account(Name='CA'+j, billingstate='CA'));
        }
        insert accounts;
    }
    static testmethod void testQueueable(){
        contact a=new contact(Lastname='mary', Firstname='rose'); 
        Test.startTest();        
        AddPrimaryContact updater=new AddPrimaryContact(a, 'CA');
        System.enqueueJob(updater);
        Test.stopTest(); 
        
        System.assertEquals(50, [SELECT count() FROM Contact WHERE Lastname='mary' AND Firstname='rose']) ;                      
    }   
}