README

Events

A simple Event, Listener,and Dispatcher

Tests

phpunit

How to use

Create a dispatcher

$dispatcher = new Dispatcher();

Extend the base event class for each of your events:

class MyEvent extends Event { }

Implement listener interface for each of your events and listeners

class MyListener implements ListenerInterface {
    ...

Implement the handle method in listener to do a specific task:

    ...
    public function handle(EventInterface $event): void { }
}

Attach listeners to event(s) in a queue:

$event = new MyEvent();

$event->attach(new MyListener());

You can assign priorities to listeners as well. The default priority is 0.

$event->attach(new MyListener(), 3);

You can attach multiple listeners using an array.

$listeners = [new MyListener(),new MyListener(),new MyListener()];
$event->attach($listeners);

Each listener attached will be assigned the given priority:

$listeners = [new MyListener(),new MyListener(),new MyListener()];

//They all get a priority of 3
$event->attach($listeners, 3);

Note that if the listeners all have the same priority, the queue will start at the first element of the first attached listener(s). Consider the following code:

$listenersA = [new MyListenerA(),new MyListenerB()];
$event->attach($listenersA);

$listenersB = [new MyListenerC(),new MyListenerD()];
$event->attach($listenersB);

When this event is dispatched, the first listener to receive the event will be MyListenerA.

You can also override the default priority by passing the listener in a numbered array with the element at index 0 is the listener and the element at index 1 is the priority:

$listeners = [new MyListener(),[new MyListener(), 2],new MyListener()];

//They all get a priority of 3, except for the the listener at index 1
$event->attach($listeners, 3);

Please note that all priorities must be integers. Priorities provided through the array interface that are not integers will be set to the default priority.

$dispatcher->register($event);

Dispatch events with class name. This will call the handle method on each listener in the priority queue.

$dispatcher->dispatch(MyEvent::class);

You can also dispatch an event without the help of a dispatcher:

$event->dispatch();

The dispatch queue can be interrupted by an exception and resume where it left off.

try {
    $event->dispatch(); // This will throw an exception from one of the listeners
} catch (ResumableException $ex) {
    //do stuff to make all better
}

//Resume the dispatch
$event->dispatch();
...

The dispatch queue may also be reset to the state it was in just before dispatch() is called:

$event->reset();

It is important to note that resuming execution of the event queue will change the cached copy of the queue. Use resumability with care.

aesonus / events

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README

Events

Tests

How to use