Why event-driven architecture decouples code in Laravel - See It in Action

Why event-driven architecture decouples code

📖 Scenario: You are building a Laravel application that sends a welcome email when a new user registers. Instead of writing all the code in one place, you want to separate the registration logic from the email sending logic.

🎯 Goal: Create a simple event-driven setup in Laravel where a UserRegistered event triggers a SendWelcomeEmail listener. This will show how event-driven architecture helps keep code separate and easier to manage.

📋 What You'll Learn

Create a UserRegistered event class with a $user property

Create a SendWelcomeEmail listener class that handles the event

Dispatch the UserRegistered event after creating a new user

Register the event and listener in the EventServiceProvider

💡 Why This Matters

🌍 Real World

Many web applications need to perform extra tasks after user actions, like sending emails or logging. Event-driven design helps keep these tasks separate and organized.

💼 Career

Understanding event-driven architecture is important for Laravel developers to write clean, maintainable, and scalable code.

1

Create the UserRegistered event class

Create a Laravel event class called UserRegistered with a public property $user to hold the user data. Add a constructor that accepts a $user parameter and assigns it to the property.

Laravel

<?php

namespace App\Events;

use Illuminate\Foundation\Events\Dispatchable;
use Illuminate\Queue\SerializesModels;

class UserRegistered
{
    use Dispatchable, SerializesModels;

    public $user;

    // Your code here
}

Need a hint?

Use public $user; and a constructor method __construct($user) to assign the user.

2

Create the SendWelcomeEmail listener class

Create a Laravel listener class called SendWelcomeEmail with a handle method that accepts a UserRegistered event parameter. Inside the method, add a comment // Send welcome email logic here.

Laravel

<?php

namespace App\Listeners;

use App\Events\UserRegistered;

class SendWelcomeEmail
{
    public function handle(UserRegistered $event)
    {
        // Your code here
    }
}

Need a hint?

Define a handle method that takes UserRegistered $event and add a comment inside.

3

Dispatch the UserRegistered event after user creation

In a controller or service, create a new user variable $user with any value (e.g., (object)["name" => "Alice"]). Then dispatch the UserRegistered event with event(new UserRegistered($user)).

Laravel

 "Alice"];

// Your code here

Need a hint?

Create a user object and dispatch the event using event(new UserRegistered($user)).

4

Register the event and listener in EventServiceProvider

In app/Providers/EventServiceProvider.php, add the UserRegistered event and SendWelcomeEmail listener to the $listen array like this: UserRegistered::class => [SendWelcomeEmail::class].

Laravel

<?php

namespace App\Providers;

use Illuminate\Foundation\Support\Providers\EventServiceProvider as ServiceProvider;
use App\Events\UserRegistered;
use App\Listeners\SendWelcomeEmail;

class EventServiceProvider extends ServiceProvider
{
    protected $listen = [
        // Your code here
    ];
}

Need a hint?

Add the event and listener classes to the $listen array in EventServiceProvider.