Signals in PHP

Try the Developer's guide

The majority of this information has moved into the Developer's guide.

However, if you can't find what you are looking for there, we recommend checking this doc set as well.

use Temporal\Workflow;

#[Workflow\WorkflowInterface]
class YourWorkflow
{
    private bool $value;

    #[Workflow\WorkflowMethod]
    public function run()
    {
        yield Workflow::await(fn()=> $this->value);
        return 'OK';
    }

    #[Workflow\SignalMethod]
    public function setValue(bool $value)
    {
        $this->value = $value;
    }
}

In the example above the workflow updates the protected value. Main workflow coroutine waits for such value to change using Workflow::await function.

To send signal to workflow use WorkflowClient->newWorkflowStub or WorkflowClient->newUntypedWorkflowStub:

$workflow = $workflowClient->newWorkflowStub(YourWorkflow::class);

$run = $workflowClient->start($workflow);

// do something

$workflow->setValue(true);

assert($run->getValue() === true);

Use WorkflowClient->newRunningWorkflowStub or WorkflowClient->newUntypedRunningWorkflowStub with workflow id to send signals to already running workflows.

$workflow = $workflowClient->newRunningWorkflowStub(YourWorkflow::class, 'workflowID');
$workflow->setValue(true);

SignalWithStart

You may not know if a Workflow is running and can accept a signal. The WorkflowClient->startWithSignal API allows you to send a signal to the current Workflow instance if one exists or to create a new run and then send the signal.

$workflow = $workflowClient->newWorkflowStub(YourWorkflow::class);

$run = $workflowClient->startWithSignal(
    $workflow,
    'setValue',
    [true], // signal arguments
    [] // start arguments
);

SignalWithStart​

SignalWithStart