Registering Module Events

#Module Events

Laravel Modules provides several event constants that help you hook into the lifecycle of a module. These events allow developers to perform specific actions when certain module-related activities occur.

#Available Event Constants

Here’s a list of available event constants, which are defined in the ModuleEvent class:

class ModuleEvent
{
    const BOOT = 'boot';
    const REGISTER = 'register';
    const DISABLING = 'disabling';
    const DISABLED = 'disabled';
    const ENABLING = 'enabling';
    const ENABLED = 'enabled';
    const CREATING = 'creating';
    const CREATED = 'created';
    const DELETING = 'deleting';
    const DELETED = 'deleted';
    const USED = 'used';
    const UNUSED = 'unused';
}

Explanation of Each Event

BOOT

• Event Trigger: This event is fired when a module is booted.
• Use Case: You can use this event to perform additional setup tasks when a module is fully booted into the application lifecycle.

REGISTER

• Event Trigger: This event is fired when a module is registered.
• Use Case: Hook into this event to register custom services, routes, or other functionalities when the module is added to the application.

DISABLING

• Event Trigger: This event is fired just before a module is disabled.
• Use Case: Use this event to perform any cleanup or save state before the module is disabled.

DISABLED

• Event Trigger: This event is fired when a module is disabled.
• Use Case: This can be used to notify other services or take actions after the module has been disabled.

ENABLING

• Event Trigger: This event is fired just before a module is enabled.
• Use Case: Hook into this event to initialize or prepare resources before a module becomes active.

ENABLED

• Event Trigger: This event is fired when a module is enabled.
• Use Case: Use this event to perform tasks once the module is successfully enabled, such as logging or setting up additional features.

CREATING

• Event Trigger: This event is fired before a new module is created.
• Use Case: Perform pre-creation tasks such as validation or preparation before a new module is added.

CREATED

• Event Trigger: This event is fired once a new module has been created.
• Use Case: You can hook into this event to carry out tasks like setting up default configurations for the newly created module.

DELETING

• Event Trigger: This event is fired just before a module is deleted.
• Use Case: Use this event to handle tasks such as backing up data or removing dependencies before the module is deleted.

DELETED

• Event Trigger: This event is fired after a module is deleted.
• Use Case: Hook into this event to remove related data, clean caches, or perform other post-deletion tasks.

USED

• Event Trigger: This event is fired when a module is marked as “used.”
• Use Case: Useful for tracking module usage or incrementing statistics related to the use of the module.

UNUSED

• Event Trigger: This event is fired when a module is marked as “unused.”
• Use Case: Perform actions like freeing up resources or reducing logs once the module is no longer actively used.

Here is how you can listen for a module event in your Laravel application:

EventServiceProvider: First, register your listeners in the EventServiceProvider like any other Laravel event.

use Nwidart\Modules\Constants\ModuleEvent;
 
class EventServiceProvider extends ServiceProvider
{
    protected $listen = [
        ModuleEvent::BOOT => [
            ModuleBootListener::class,
        ],
    ];
}

Listener Class: Define the corresponding listener to handle the event logic.

namespace App\Listeners;
 
class ModuleBootListener
{
    public function handle($event)
    {
        // Your logic when the module boots
    }
}

These events allow developers to extend the functionality of Laravel Modules by hooking into key lifecycle events. Using these constants helps create a more modular and event-driven application.

#Registering Module Events

Your module may contain events and event listeners. You can create these classes manually, or with the following artisan commands:

Generate an event:

php artisan module:make-event BlogPostWasUpdatedEvent Blog

Generate an event listener:

php artisan module:make-listener NotifyAdminOfNewPostListener Blog

Once those are created you need to register them. This can be done in 2 ways:

#Manually registering events

Register events manually in your module service provider register method:

$this->app['events']->listen(BlogPostWasUpdatedEvent::class, NotifyAdminOfNewPostListener::class);

#Creating an EventServiceProvider

Once you have multiple events, you might find it easier to have all events and their listeners in a dedicated service provider. This is what the EventServiceProvider is for.

Create a new class called for instance EventServiceProvider in the Modules/Blog/Providers folder (Blog being an example name).

This class needs to look like this:

<?php
 
namespace Modules\Blog\App\Providers;
 
use Illuminate\Foundation\Support\Providers\EventServiceProvider as ServiceProvider;
 
class EventServiceProvider extends ServiceProvider
{
    protected $listen = [];
}

Don't forget to load this service provider in the register method of the ModuleServiceProvider class.

$this->app->register(EventServiceProvider::class);

This is now like the regular EventServiceProvider in the app/ namespace. In our example the listen property will look like this:

<?php
 
namespace Modules\Blog\App\Events;
 
use Illuminate\Foundation\Support\Providers\EventServiceProvider as ServiceProvider;
 
class EventServiceProvider extends ServiceProvider
{
    protected $listen = [
        BlogPostWasUpdatedEvent::class => [
            NotifyAdminOfNewPostListener::class,
        ],
    ];
}