Creating an Event

Creating an event simply sets a callback to be invoked if and only if during the execution of the current program such an event is triggered. This is useful if you require notification of certain actions throughout your application.

Registering an Event

Before registering an event you will need to build a Listener to register the event with.setup an event listener:

// Code that inherits from AppController or AppModel may retrieve an instance of the \Blesta\Core\Util\Events\EventFactory from the container by calling $this->getFromContainer('util.events')
$eventFactory = $this->getFromContainer('util.events');
$eventListener = $eventFactory->listener();

// If you are working in a location that does not inherit from AppController or AppModel, you can load the \Blesta\Core\Util\Events\EventFactory yourself
$eventFactory = new \Blesta\Core\Util\Events\EventFactory();
$eventListener = $eventFactory->listener();

Registering an event will allow your callback to be notified when such an event is triggered.

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In the above example, when the "EventName" event is triggered the "callbackMethod" will be invoked on the object that registered the event. If you are registering one of the core events available on the Event Handlers page, the second argument to register (i.e. the callback) can be omitted and Blesta will use its predefined callback to perform all related event actions.

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Triggering an event invokes all callbacks that have been registered for that event. To trigger the "EventName" event invoke the Listener's trigger method and pass in an Event  \Blesta\Core\Util\Events\Common\EventInterface that will be passed to each callback.

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<?php
class MyController extends AppController 
{
    public function index()
    {
		// Register the 'EventName' and have it trigger our 'callbackMethod'
		$eventFactory = $this->getFromContainer('util.events');
        $eventListener = $eventFactory->listener();
        $eventListener->register('EventName', [$this, 'callbackMethod']);
        $eventListener->trigger($eventFactory->event('EventName', ['square', 'pink']));
        return false; // don't render a view
    }

    public function callbackMethod($event)
    {
        $params = $event->getParams();
        echo $params[0] . "' "' . $params[1]; // square pink
    }
}
?>

Returning Data From an Event

The \Blesta\Core\Util\Events\Common\EventInterface The Event  passed to each event callback contains setters and getters for both parameters (as seen above when Triggering triggering an Eventevent) and return values. Expanding on the example above, we can set our return value using the Event \Blesta\Core\Util\Events\Common\EventInterface::setReturnValue() method. This will output "square".

<?php
class MyController extends AppController {
    public function index()
    {
        $eventFactory = $this->getFromContainer('util.events');
        $eventListener = $eventFactory->listener();
        $eventListener->register('EventName', [$this, 'callbackMethod']);
        $eventListener->trigger($eventFactory->event('EventName', ['square', 'pink']));
        echo $event->getReturnValue(); // square
        return false; // don't render a view
    }
    
    public function callbackMethod($event)
    {
        $params = $event->getParams();
        $event->setReturnValue($params[0]);
    }
}
?>

Creating

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Events prior to Blesta version 4.3.0

Creating an event simply sets a callback to be invoked if and only if during the execution of the current program such an event is triggered. This is useful if you require notification of certain actions throughout your application.

...