PHP Event Dispatcher

PHP Event Dispatcher is the most easy-to-use and simple Event Dispatcher PHP Class (Singleton Pattern).

The original idea is from Symfony's event listener system. http://symfony.com/doc/current/components/event_dispatcher/index.html

But I think it is a bit complex to me, I just want a simple Event Dispatcher for my project. Therefore I made this for myself, and someone else needs the simple EventDispatcher.

Installation

Download class.event.php to your project folder, and then include it anywhere.

include_once('class.event.php');

PHP Event Dispatcher is designed as Singleton Pattern, you can not call it by New EventDispatcher() Just because to make sure that only an Event Dispatcher to handle all events.

Use the following global functions to use PHP Event Dispatcher, you can put it anywhere and easily inject in any framework.

How to use

Add a listener function to an event

addListener('event_name', 'function_name');

Run this event

doDispatch('event_name');

Remove a listener function from an envet

Return: true / false

removeListener('event_name', 'function_name');

Check out if there is any listener defined by an event

Return: true / false

hasListener('event_name');

Check if an event Listener actually exists

Return: true / false

isListening('event_name');

Check current running event Listener

nowListener();

Examples

test.php

<?php

include_once('class.event.php');

addListener('event_send_message', 'send_message');

function send_message() {
    echo '<p>A message has been sent!!</p>';
    echo '<p>Current Running Event is called: <strong>' . nowListener() . '</strong></p>';
}

doDispatch('event_send_message');

$event_name = 'event_send_message';

if ( hasListener($event_name) ) {
    echo '<p>Listener <strong>' . $event_name . '</strong> is existed.<p>';
}
else {
  echo '<p>Listener <strong>' . $event_name . '</strong> is not existed.<p>';
}

?>