Events

• Event listener
• Observable trait

Mako includes two ways of handling events, an event listener and a trait that makes your class observable.

Event listener

The register method lets you register an event handler that will get executed when the event is triggered. You can register multiple handlers for the same event. They will be executed in the order that they were registered.

$this->event->register('foobar', function()
{
	return 'foobar event handler';
});

You can also handle your events using a class instead of a closure.

$this->event->register('foobar', 'app\events\FoobarHandler');

Class handlers will be instantiated by the dependency injection container so you can easily inject your dependencies through the constructor. Both closure and class handlers will be executed by the Container::call() and all dependencies will automatically be injected there as well.

<?php

namespace app\events;

use mako\event\EventHandlerInterface;

class FoobarHandler implements EventHandlerInterface
{
	public function handle()
	{
		return 'foobar event handler';
	}
}

The has method will return TRUE if an event handler has been registered and FALSE if not.

$registered = $this->event->has('foobar');

The clear method will clear all event handlers registered for an event.

$this->event->clear('foobar');

The override method will clear all previously registered handlers for an event before registering a new handler.

$this->event->override('foobar', function()
{
	return 'foobar event 1';
});

The trigger method run all handlers for the registered event and return an array containing all the return values.

$values = $this->event->trigger('foobar');

You can also pass arguments your handlers using the optional second parameter.

$values = $this->event->trigger('foobar', [1, 2, 3]);

The third optional parameter lets you stop event handling if one of the handlers return FALSE.

$values = $this->event->trigger('foobar', [1, 2, 3], true);

Observable trait

Your class must use the ObservableTrait in order to be obserable.

class Observable
{
	use mako\event\ObsevableTrait;
}

$observable = new Observable;

The attachObserver method allows you to attach an observer to your class. You can attach multiple observers for the same event.

$observable->attachObserver('foobar', function()
{
	return 'foobar event';
});

The hasObserver method returns TRUE if an event has an observer and FALSE if not.

$observed = $observable->hasObserver('foobar');

The clearObservers will clear all observers. You can also specify which event you want to clear.

$observable->clearObservers();

$observable->clearObservers('foobar');

The overrideObservers method clears all observers for an event and registers a new one.

$observable->overrideObservers('foobar', function($string)
{
	return mb_strtoupper($string);
});

The notifyObservers method will notify all observers of an event and return an array containing all of their return values.

$returnValues = $this->notifyObservers('foobar', 'hello, world!');

The notifyObservers method is protected and can only be called from within the observable class.