Leveraging Eloquent Model Events for Side Effects

<?php

// app/Models/Product.php
namespace App\Models;

use Illuminate\Database\Eloquent\Model;
use Illuminate\Support\Facades\Log;

class Product extends Model
{
    protected $fillable = ['name', 'price', 'stock'];

    protected static function booted()
    {
        static::creating(function (Product $product) {
            // Auto-set a slug before a product is created
            $product->slug = \Illuminate\Support\Str::slug($product->name);
            Log::info("Creating product: {$product->name}");
        });

        static::updated(function (Product $product) {
            // Log changes after a product is updated
            Log::info("Product updated: {$product->id} - {$product->name}");
            // You might trigger a cache invalidation here
        });

        static::deleted(function (Product $product) {
            // Perform cleanup, e.g., delete related files or clear cache
            Log::warning("Product deleted: {$product->id} - {$product->name}");
        });

        static::retrieved(function (Product $product) {
            // Perform actions after a model is retrieved from the database
            // For example, initialize a calculated attribute
            $product->is_expensive = $product->price > 1000;
        });
    }
}

// Example Usage (e.g., in a controller or test):
$product = Product::create(['name' => 'New Gadget', 'price' => 299.99, 'stock' => 10]);
// The 'creating' event fired and set the slug, and logged.

$product->price = 329.99;
$product->save();
// The 'updated' event fired and logged the change.

$product = Product::find(1); // 'retrieved' event fires
// $product->is_expensive is now set

$product->delete();
// The 'deleted' event fired and logged the deletion.