Laravel Events For Newbies

What is Event-Driven Programming?

Simply put, events are actions that occur within an application. Coming from the world of JavaScript, you probably understand events as user actions such as mouse click, mouseover, key press etc. In Laravel, events can be various actions that occur within an application such as email notifications, logging, user sign up, CRUD operations etc. Laravel events provide a simple observer implementation, allowing you to subscribe and listen for various events that occur in your application.

Why should we use Events?!

• Easier to maintain (SOLID).
• Less risk of regression,
• Make classes responsible for only one thing,
• Make team’s work easier,
• Expects the unexpected, If you ever need to add new functionality, all you need to do is create a new listener and register it with the event. Job is done!
• Your logic is separated and now the Controller has much - reduced responsibility
• Allow asynchronous tasks easily (queues in Laravel).
• Be ready for broadcasting

Let's compare two pieces of code with/without events

With

Without

How do we create Events?

Defining Our Events

    php artisan make:event UserRegistered

Event has been created successfully

     artisan make:listener SendWelcomeMail --event=UserRegistered

Listener has been created successfully

     artisan make:listener SignupForWeeklyNewsletter --event=UserRegistered

Listener has been created successfully

     artisan make:listener SendSMS --event=UserRegistered

Listener has been created successfully

ESP - EventServiceProvider

     artisan event:generate

Events and Listeners generated successfully

Stopping The Propagation Of An Event

Eloquent Native Events

With his Eloquent model, Laravel will automatically fire created, saved, updated and deleted events respectively.

To start listening to model events, define a $dispatchesEvents property on your Eloquent model. This property maps various points of the Eloquent model's lifecycle to your own event classes. Each model event class should expect to receive an instance of the affected model via its constructor.

Eloquent Native Events