Observer in Laravel is used to do any operations that may be needed before or after any CUD operations on a model. Like before Creating a record, After record is created in the model. Similarly before updating a record and after record is updated etc..
How to create observer?
> php artisan make:observer ProductObserver –model=Product
If Observers directory is not available already, this command will create Observers directory with in app directory
Along with this, ProductObserver.php file will be created
App/Observers/ ProductObserver.php
<?php
namespace App\Observers;
use App\Models\Product;
class ProductObserver
{
/**
* Handle the Product "creating" event.
* @param \App\Models\Product $product
* @return void
*/
public function creating(Product $product): void
{
\Log::info("Product is being created: " . $product->name);
}
/**
* Handle the Product "created" event.
*/
public function created(Product $product): void
{
\Log::info("Product is created: " . $product->name);
}
/**
* Handle the Product "updating" event.
*/
public function updating(Product $product): void
{
\Log::info("Product is being updated: " . $product->name);
}
/**
* Handle the Product "updated" event.
*/
public function updated(Product $product): void
{
\Log::info("Product is updated: " . $product->name);
}
/**
* Handle the Product "deleted" event.
*/
public function deleted(Product $product): void
{
}
/**
* Handle the Product "restored" event.
*/
public function restored(Product $product): void
{
//
}
/**
* Handle the Product "force deleted" event.
*/
public function forceDeleted(Product $product): void
{
//
}
}
How observer works?
Before events are triggered before database operation. These are
Creating: When a new record is about to be saved
Updating: When an existing record is about to be updated
Deleted: When an existing record is about to be deleted
After events are triggered after db operation is completed.
Created: This is triggered when record is saved in the db
Updated: When record is updated
Deleted: When record deletion is complete
How these actions are triggered?
To trigger these observer events,
go to
app > Providers > AppServiceProvider.php
Assume we need to create Observer for Product model
Open AppServiceProvider.php file, It will look like as shown below
<?php
namespace App\Providers;
use Illuminate\Support\ServiceProvider;
use App\Models\Product;
use App\Observers\ProductObserver;
class AppServiceProvider extends ServiceProvider
{
/**
* Register any application services.
*/
public function register(): void
{
//
}
/**
* Bootstrap any application services.
*/
public function boot(): void
{
//
}
}And it will look as shown below after making changes in it
<?php
namespace App\Providers;
use Illuminate\Support\ServiceProvider;
use App\Models\Product;
use App\Observers\ProductObserver;
class AppServiceProvider extends ServiceProvider
{
/**
* Register any application services.
*/
public function register(): void
{
//
}
/**
* Bootstrap any application services.
*/
public function boot(): void
{
Product::observe(ProductObserver::class);
}
}Test the Observer
You can test the observer by creating or updating a product using Tinker or a controller.
Using Tinker:
> php artisan tinker
> use App\Models\Product;
// Create a product
> Product::create(['name' => 'Sample Product', 'stock' => 10]);
// Update the stock
> $product = Product::first();
> $product->update(['stock' => 3]);
// Delete the product
> $product->delete();Log Output:
In the storage/logs/laravel.log, you’ll see:
[INFO] A new product is being created: Sample Product
[INFO] Product created: Sample Product, Stock: 10
[INFO] Stock updated for ‘Sample Product’: Old Stock = 10, New Stock = 3
[WARNING] Low stock alert for ‘Sample Product’: Stock = 3
[INFO] Product deleted: Sample Product
Limitation
Observer works only with Eloquent ORM and not with query builder