Events

Phpab makes use of an event dispatcher. The event dispatcher can be used to attach event listeners to so that action can be taken when events happen within the library.

The library supports multiple implementations of an event dispatcher. By default the following implementations exists:

• Default dispatcher: An event dispatcher composed by the phpab team;
• Symfony dispatcher: This event dispatcher makes use of Symfony's event-dispatcher library.
• Zend dispatcher: This dispatcher makes used of Zend Framework's event manager.

Dispatching

Simple Dispatcher

The, what we call, Simple Dispatcher is a dispatcher class that is implemented by the PhpAb team itself. It's a very simple implementation to which you add listeners and subscribers. When an event is dispatched, the listeners are invoked.

Usage is simple:

$dispatcher = new \PhpAb\Event\Dispatcher();

To add a listener:

$dispatcher->addListener('my-event', function() {
    // The callback that is invoked. Parameters depend on the event.
});

To add a subscriber:

// The Google data collector implements SubscriberInterface but
// of course you can create your own as well.
$subscriber = new \PhpAb\Analytics\DataCollector\Google();
$dispatcher->addSubscriber($subscriber);

Symfony bridge

The Symfony bridge can be used to create an event dispatcher from the symfony/event-dispatcher library. It does not have support for [SubscriberInterface]() at the moment.

Zend Framework bridge

The Zend Framwork bridge can be used to create an event dispatcher from the zendframework/zend-eventmanager library. It does not have support for [SubscriberInterface]() at the moment.

Event Types

Note that all events are dispatched from the Engine class (https://github.com/phpab/phpab/blob/master/src/Engine/Engine.php). The library has the following events:

phpab.participation.block

The phpab.participation.block event is dispatched when a user did not participate in the test yet and when the participation manager decided that the user should not participate in the particular test.

phpab.participation.blocked

The phpab.participation.blocked event is dispatched when the a user already was excluded for a test by the participation manager and the user visits the page again in a new request.

phpab.participation.variant_missing

The phpab.participation.variant_missing event is dispatched when no variant has been chosen by the variant chooser or when the variant no longer exists. This can happen when the user has a cookie set but the code has changed for example.

phpab.participation.variant_run

The phpab.participation.variant_run event is dispatched when a variant is activated. This will happen for new users as well as for existing users.