jessegall/php-events

v0.1.1 2022-12-28 15:31 UTC

Requires (Dev)

• phpunit/phpunit: ^9.5
• symfony/var-dumper: ^6.1

MIT

• Jesse Gall

README

A simple event dispatcher for PHP that allows you to easily register listeners for specific events and dispatch those events to their listeners.

Installation

composer require jessegall/php-events

Usage

To use the event dispatcher, you will first need to create an instance of the Dispatcher class:

use JesseGall\Events\Dispatcher;

$dispatcher = new Dispatcher();

Registering listeners

To register a listener for an event, you can use the listen method:

$dispatcher->listen('event_name', $listener);

The $listener argument can be an instance of a class that implements a handle method, a string representing the name of a class that has a handle method, or a closure:

class MyListener
{
    public function handle($payload)
    {
        // Handle the event
    }
}

// Register listener using an instance of a class
$dispatcher->listen('event_name', new MyEventListener());

// Register a listener using a class
$dispatcher->listen('event_name', MyEventListener::class);

// Register a listener as a closure
$dispatcher->listen('event_name', function ($payload) {
    // Handle the event
});

You can also register multiple listeners at once by passing an array of listeners:

$dispatcher->listen('event_name', [$listener1, $listener2, $listener3]);

Alternatively, you can use an event class to register listeners. An event class is a class that implements the Event interface. To register listeners for an event class, you can use the listen method just as you would with a string event name:

$dispatcher->listen(UserRegistered::class, $listener);

Dispatching events

To dispatch an event to all of its registered listeners, you can use the dispatch method:

$dispatcher->dispatch('event_name', $payload);

When you dispatch an event with a string event name, you can pass a single payload value as an argument to the dispatch method. This payload value will be passed to the handle method of each listener when the event is dispatched.

$dispatcher->dispatch('event_name', ['foo' => 'bar']);

class MyListener
{
    public function handle(array $payload)
    {
        // $payload will be ['foo' => 'bar']
    }
}

On the other hand, if you dispatch an event with an event instance, the event object is passed as the payload to the handle method of each listener when the event is dispatched:

$dispatcher->dispatch(new UserRegistered($user));

class MyListener
{
    public function handle(UserRegistered $event)
    {
        // Payload will be the dispatched event instance
    }
}