queue.md

Event Queue

An event queue lets you fire events with multiple payloads at a delayed time. Using queue's is a great way to organize events. Where events are only fired with one payload, queue's can hold multiple payloads and listeners, and run through them in one go.

Setting up a Queue

$queue = new Fuel\Event\Queue();

Adding payloads to the queue

$queue->queue('name', array('param 1 - a', 'param 2 - a'));

// Add another one.
$queue->queue('name', array('param 1 - b', 'param 2 - b'));

You've now got 2 payloads in the queue, ready to get cracking.

Registering Flushers (Listeners, Workers, ...)

Where in events callbacks are often referred to as Listeners, in Queue they're commonly known as Flushers or Workers. Registering a Flusher works just like adding a Listener to a Container:

$queue->on('name', $callable_flusher, $context, $priority);

As you can see in the code above, the queue on method can also take a $priority param. Like in events emitted from a Container, this will sort the Flushers descending.

$queue->queue('name', array('Hello', 'World'));

$queue->on('name', function($event, $one, $two){
	echo $two.'!';
}, 1);

$queue->on('name', function($event, $one, $two){
	echo $one.' ';
}, 2);

When flushed this will echo out Hello World!.

Flushing the queue

In order to run the queued payloads by the Flushers you'll have to flush().

$result = $queue->flush('name');

When only using one Flusher, you can also define it in the flush call.

$result = $queue->flush('name', function(){
	// Flusher logic.
}, $optional_context);

Flush results.

The result of the flushing is a multidimentional array:

result_array(
	payload_one_array(
		flusher_one_payload_one_result(),
		flusher_two_payload_one_result(),
	),
	payload_two_array(
		flusher_one_payload_two_result(),
		flusher_two_payload_two_result(),
	)
)