Dispatcher

Inspired by the Symfony Event Dispatcher Component, this module allows you to create event driven applications.

It differs from the K2 Event class in a number of ways:

• It's not a singleton, which makes it a lot easier to test the system and create multiple dispatchers
• Event data is encapsulated, allowing you can trigger events within events

Unit Testing

At time of writing this module has 95.65% code coverage, ensuring the reliability of the API through development.

To run the tests yourself you should install the official unittest module and run the modules.dispatcher group.

Examples

If you look in the unit tests you'll find lots of examples on how it works, but here are a quick few:

// Here we're using the "global" dispatcher, so anything can add events
Dispatcher::instance()
    ->register_listener('post.pre_publish', array('Misc_Class', 'callback'));

// Later on...
Dispatcher::instance()
    // Calls Misc_Class::callback();
    ->trigger_event('post.pre_publish', Dispatcher::event(array('argument_name' => 'value'));

Inside the callback:

Class Misc_Class
{
    // First argument passed is the name of the triggered event, and the second
    // is a Dispatcher_Event object which encapsulates any arguments
    function callback($event_name, Dispatcher_Event $event)
    {
        // You can access arguments in two different ways:

        // Through __get()
        $var = $event->arguments['argument_name'];

        // Or via ArrayAccess
        $var = $event['argument_name'];
    }
}

The latter method is reccomended & preferred.