Queries

Queries allow you to retrieve information about the current state of a workflow without affecting its execution. This is useful for monitoring and debugging purposes.

To define a query method on a workflow, use the QueryMethod annotation:

use Workflow\QueryMethod;
use Workflow\Workflow;

class MyWorkflow extends Workflow
{
    private bool $ready = false;

    #[QueryMethod]
    public function getReady(): bool
    {
        return $this->ready;
    }
}

To query a workflow, call the method on the workflow instance. The query method will return the data from the workflow.

use Workflow\WorkflowStub;

$workflow = WorkflowStub::load($workflowId);

$ready = $workflow->getReady();

Important: Querying a workflow does not advance its execution, unlike signals.

Updates

Updates allow you to retrieve information about the current state of a workflow and mutate the workflow state at the same time. They are essentially both a query and a signal combined into one.

To define an update method on a workflow, use the UpdateMethod annotation:

use Workflow\UpdateMethod;
use Workflow\Workflow;

class MyWorkflow extends Workflow
{
    private bool $ready = false;

    #[UpdateMethod]
    public function updateReady($ready): bool
    {
        $this->ready = $ready;

        return $this->ready;
    }
}

Outbox

The outbox collects outgoing query messages and lets you produce them exactly once, even if the workflow is replayed or resumed multiple times.

use Workflow\UpdateMethod;
use Workflow\Workflow;

class MyWorkflow extends Workflow
{
    #[UpdateMethod]
    public function receive()
    {
        if ($this->outbox->hasUnsent()) {
            return $this->outbox->nextUnsent();
        }
    }

    public function execute()
    {
        $count = 0;
        while (true) {
            $count++;

            $this->outbox->send("Message {$count}");
        }
    }
}

Each sent signal is stored in the outbox. The outbox tracks which messages have already been sent. On replay, previously read messages remain sent. Only unsent messages are returned by nextUnsent(). This makes the outbox safe to send multiple messages inside long-running loops.