Defining events in Laravel - Step-by-Step Execution

Concept Flow - Defining events

Create Event Class

↓

Define Event Properties

↓

Create Listener Class

↓

Register Event and Listener

↓

Fire Event in Code

↓

Listener Handles Event

This flow shows how you create an event class, define its data, create a listener, register both, then fire the event so the listener reacts.

Execution Sample

Laravel

php artisan make:event OrderShipped

class OrderShipped {
  public $order;
  public function __construct($order) {
    $this->order = $order;
  }
}

This code creates an event class named OrderShipped that holds an order object passed when the event is fired.

Execution Table

Step	Action	Code/Command	Result/State Change
1	Create event class	php artisan make:event OrderShipped	OrderShipped.php file created with class skeleton
2	Add property and constructor	public $order; public function __construct($order) { $this->order = $order; }	Event class now holds order data
3	Create listener class	php artisan make:listener SendShipmentNotification	Listener class created to handle event
4	Register event and listener	In EventServiceProvider.php, add to $listen array	Laravel knows which listener to call for OrderShipped
5	Fire event in code	event(new OrderShipped($order));	Event dispatched, listeners triggered
6	Listener handles event	public function handle(OrderShipped $event) { // send notification }	Notification sent using event data
7	Exit	No more listeners	Event handling complete

💡 All listeners for the event have run, so event processing stops.

Variable Tracker

Variable	Start	After Step 2	After Step 5	Final
$order	null	passed to constructor	passed to event instance	used in listener to send notification
OrderShipped instance	none	created with $order	dispatched via event()	passed to listener handle()

Key Moments - 3 Insights

Why do we need to define properties and a constructor in the event class?

Because the event needs to carry data (like $order) to listeners. Step 2 shows adding these so listeners can access event info.

How does Laravel know which listener to run for an event?

In Step 4, the event and listener are registered in EventServiceProvider.php. This mapping tells Laravel which listener handles which event.

What happens when we call event(new OrderShipped($order))?

Step 5 shows firing the event. Laravel dispatches it and calls all registered listeners, as seen in Step 6.

Visual Quiz - 3 Questions

Look at the execution table, what is created at Step 1?

A An event class file named OrderShipped.php

B A listener class file named SendShipmentNotification.php

C The EventServiceProvider.php file

D The notification email

💡 Hint

Check Step 1 in the execution_table where the event class is created.

At which step is the event fired so listeners start working?

A Step 3

B Step 5

C Step 2

D Step 6

💡 Hint

Look at Step 5 in execution_table where event(new OrderShipped($order)) is called.

If we forget to register the listener in EventServiceProvider, what happens?

A The listener still runs automatically

B The event class won't be created

C The listener won't run when the event fires

D The event won't fire at all

💡 Hint

Refer to Step 4 where registration links event and listener.

Concept Snapshot

Defining events in Laravel:
1. Create event class with php artisan make:event.
2. Add properties and constructor to pass data.
3. Create listener class.
4. Register event-listener in EventServiceProvider.
5. Fire event with event(new EventName(data));
6. Listener handles event data.

Full Transcript

In Laravel, defining events starts by creating an event class using artisan. This class holds any data you want to pass to listeners, like an order object. Next, you create a listener class that will respond when the event fires. You must register the event and listener in the EventServiceProvider so Laravel knows which listener to call. When you fire the event in your code using event(new EventName(data)), Laravel dispatches it and calls all registered listeners. The listener then handles the event, for example sending a notification. This process helps separate concerns and makes your app more organized.