Documentation (#18)

docs/components/event-dispatcher/index.md

@@ -2,8 +2,56 @@
 title: Event Dispatcher - Overview
 ---
 
+# Event Dispatcher
+
+Event Dispatcher will allow you to attach listeners and notify those listeners
+so they can handle the event that you dispatch. The Event Dispatcher is PSR-14
+Compatible with extra features.
+
+## Features
+
+* Event Names
+* Event Subscribers
+* Listener Priorities
+
+
 ## Installation
 
 ```shell
 composer require sonsofphp/event-dispatcher
 ```
+
+## Usage
+
+```php
+<?php
+
+use SonsOfPHP\Component\EventDispatcher\EventDispatcher;
+
+$dispatcher = new EventDispatcher();
+
+// If you have a custom ListenerProviderInterface you can inject it into the
+// EventDispatcher
+//$dispatcher = new EventDispatcher($provider);
+
+$dispatcher->addListener($event::class, function ($event, $eventName, $dispatcher) {});
+$dispatcher->addListener('event.name', function ($event, $eventName, $dispatcher) {});
+$dispatcher->addSubscriber($subscriber);
+
+$dispatcher->dispatch($event); // PSR-14
+$dispatcher->dispatch($event, 'event.name'); // Custom Event Name
+```
+
+### Event Subscribers
+
+Must implement `EventSubscriberInterface`.
+
+### Listener Priorities
+
+```php
+$dispatcher->addListener('event.name', function () {}, $priority);
+```
+
+The priority will default to `0`. Lower numbers are higher priority. Higher
+numbers will be handled later. For example, a listener with a priority of `-1`
+will be handled before a listener of priority `1`.