This class provides a way for developers to create a process of Queueable classes. This implementation facilitates the handoff of data into the overarching process and from one process step to the next. While functionally similar to the way a 'Promise' pattern allows you chain async methods together. However, a true Promise pattern resolves itself, one way or another, within the same transaction. Therefore, this is not a true Promise pattern, but an elegant way to logically chain Salesforce Queueables together. As a Developer, you'll need to extend this class, implementing the necessary execute method. Your execute method will be invoked asynchronously as part of a Queueable. You can then chain additional Queueables together using the then method provided by this class. <br> As each 'step' of the chain is completed the transaction finalizer will be constructed with the remaining steps and any passthrough data you specify. Passthrough data allows you to pass data between steps.

Implements

Queueable, Database.AllowsCallouts

public processSteps

List<QueueableProcess>

public dataPassthrough

Object

public queueableContextHistory

List<QueueableContext>

public finalizerContextHistory

List<FinalizerContext>

TESTVISIBLE

private static defaultHandleExceptionCalled

Boolean

SUPPRESSWARNINGS

this is a constructor that is used by extension classes;

protected QueueableProcess()

This method provides a syntactic sugar for adding a new QueueableProcess to the chain.

public QueueableProcess then(QueueableProcess toAdd)

QueueableProcess

Returns a Queueable Process instance that can be used to chain additional QueueableProcess instances.

This method starts the QueueableProcess chain. It's the entry point for the process.

public Id start()

Id

Id - Id of the Enqueued job.

This method starts the QueueableProcess chain. It's the entry point for the process.

public Id start(Object initialPassthrough)

Id

Id - Id of the Enqueued job.

This must be implemented by extending classes. Developers - implement this method with the work you want executed asynchronously.

public abstract void execute()

void

this is a default implementation of an handleError method. It's called by the finalizer if the developer doesn't implement their own handleError method. Developers can write per-step error handling by implementing their own handleError method as public override void handleError(Exception incomingException)

public virtual void handleException(Exception incomingException)

void

This is required by the Queueable interface. It's the essence of how the QueueableProcess pattern is implemented in Apex.

public virtual void execute(QueueableContext context)

void