laravel

Laravel

Laravel is an expressive PHP web application framework providing an elegant developer experience with Eloquent ORM, robust queues, events, and native real-time broadcasting.

When to Use

• Enterprise Full-Stack PHP Web Applications: Building robust web portals with Eloquent ORM, Blade, and queues.
• Modern Monoliths with Inertia.js: Pairing Laravel backend routes directly with React or Vue frontends without API boilerplate.
• High-Velocity REST APIs: Utilizing Laravel API Resources, Sanctum authentication, and Form Requests.
• Real-Time Applications with Laravel Reverb: First-party WebSocket broadcasting and real-time dashboard events.

Quick Start

// routes/web.php
Route::get('/', function () {
    return view('welcome');
});

// app/Models/User.php // Elegant Active Record $users = User::where('active', 1)->get();

## Core Concepts

### Eloquent ORM with Relationships & Scopes

Expressive database models with type hinting:

```php
namespace App\Models;

use Illuminate\Database\Eloquent\Model;
use Illuminate\Database\Eloquent\Relations\HasMany;
use Illuminate\Database\Eloquent\Builder;

class Customer extends Model
{
    protected $fillable = ['name', 'email', 'is_active'];

    public function orders(): HasMany
    {
        return $this->hasMany(Order::class);
    }

    // Local query scope
    public function scopeActive(Builder $query): void
    {
        $query->where('is_active', true);
    }
}

Form Requests & Validated Controllers

Strict input validation separated from controller logic:

namespace App\Http\Requests;

use Illuminate\Foundation\Http\FormRequest;

class StoreOrderRequest extends FormRequest
{
    public function authorize(): bool
    {
        return $this->user() !== null;
    }

    public function rules(): array
    {
        return [
            'customer_id' => 'required|exists:customers,id',
            'amount' => 'required|numeric|min:0.01',
            'items' => 'required|array|min:1',
            'items.*.product_id' => 'required|integer',
            'items.*.qty' => 'required|integer|min:1',
        ];
    }
}

// In Controller:
namespace App\Http\Controllers;

use App\Http\Requests\StoreOrderRequest;
use App\Models\Order;
use Illuminate\Http\JsonResponse;

class OrderController extends Controller
{
    public function store(StoreOrderRequest $request): JsonResponse
    {
        $validated = $request->validated();
        $order = Order::create($validated);

        return response()->json($order, 201);
    }
}

Asynchronous Queue Workers & Jobs

Offloading heavy processing to Redis or SQS workers:

namespace App\Jobs;

use App\Models\Order;
use Illuminate\Bus\Queueable;
use Illuminate\Contracts\Queue\ShouldQueue;
use Illuminate\Foundation\Bus\Dispatchable;
use Illuminate\Queue\InteractsWithQueue;
use Illuminate\Queue\SerializesModels;
use Illuminate\Support\Facades\Mail;

class ProcessInvoiceJob implements ShouldQueue
{
    use Dispatchable, InteractsWithQueue, Queueable, SerializesModels;

    public function __construct(public Order $order) {}

    public function handle(): void
    {
        // Generate PDF and send invoice email
    }
}

Common Patterns

Eloquent Scope and Queue Dispatch

Problem: Processing heavy invoice calculations synchronously blocks user HTTP requests.

Solution: Dispatch queued jobs with Eloquent local scopes:

namespace App\Http\Controllers;

use App\Models\Order;
use App\Jobs\ProcessInvoiceJob;
use Illuminate\Http\JsonResponse;

class OrderController extends Controller
{
    public function complete(int $id): JsonResponse
    {
        $order = Order::active()->findOrFail($id);
        $order->update(['status' => 'completed']);

        // Dispatch to background queue worker
        ProcessInvoiceJob::dispatch($order)->onQueue('invoices');

        return response()->json(['message' => 'Order completed, invoice queued']);
    }
}

Best Practices

Do:

• Target Laravel 11/12 with streamlined application structure and minimal configuration files.
• Use Form Requests for input validation instead of validating inline inside controllers.
• Utilize Eloquent eager loading (with(['customer', 'items'])) to prevent N+1 queries.
• Run queue workers under supervisor with Redis for reliable background job execution.

Don't:

• Execute raw database queries in Blade views or controllers; use Eloquent or repository classes.
• Run migrations directly in production without a verified backup and dry run.
• Commit the .env file to source control.

Troubleshooting

Error	Cause	Solution
No application encryption key has been specified	APP_KEY missing in .env configuration file.	Run php artisan key:generate.
Class '...' not found / Target class does not exist	Namespace mismatch or service provider not loaded.	Run composer dump-autoload and check namespace in config/app.php.
SQLSTATE[HY000] [2002] Connection refused	Database service down or .env DB host/port misconfigured.	Verify database credentials and host (127.0.0.1 vs localhost).

References

• Laravel Documentation