Where to Register an Observer?

I am using Laravel 9 and need to register an "Observer". This is my observer:

<?php

namespace App\Observers;

use App\Models\Post;
use Illuminate\Support\Facades\Auth;

class PostObserver
{
    public function creating(Post $post)
    {
        $post->created_by = Auth::id();
    }

    public function updating(Post $post)
    {
        $post->updated_by = Auth::id();
    }
}

This is the related code in my model:

public function createdBy()
{
    return $this->belongsTo(User::class, 'created_by');
}

public function updatedBy()
{
    return $this->belongsTo(User::class, 'updated_by');
}

I believe I need to add the observer to EventService Provider, maybe?

protected $observers = [
    Post::class => PostObserver::class,
];

What is the proper code I need and where should it gp?

martinbean

2 years ago

Level 80

@phayes0289 https://laravel.com/docs/9.x/eloquent#observers:

To register an observer, you need to call the observe method on the model you wish to observe. You may register observers in the boot method of your application's App\Providers\EventServiceProvider service provider

Alternatively, you may list your observers within an $observers property of your applications' App\Providers\EventServiceProvider class

kokoshneta

2 years ago

Level 27

@martinbean The code given in the question matches the second of these options – except that the observer(s) should be enclosed in an array:

protected $observers = [
	Post::class => [PostObserver::class],
];

1 like

martinbean

2 years ago

Level 80

@kokoshneta Using a class string as the value is perfectly fine too, Laravel accepts both.

kokoshneta

2 years ago

Level 27

@martinbean Ah, you’re right, it does an Arr::wrap() on it first. Then the code given in the question should be perfectly fine as is.

newbie360

2 years ago

Level 24

@phayes0289 Or use closures https://laravel.com/docs/9.x/eloquent#events-using-closures

class User extends Model
{
    /**
     * The "booted" method of the model.
     *
     * @return void
     */
    protected static function booted()
    {
        static::observe(\App\Observers\PostObserver::class);
    }
}

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