Laravel Patterns

Laravel Development Patterns

When to Use This Skill

• Building Laravel web applications and APIs
• Implementing authentication and authorization
• Database modeling with Eloquent ORM
• Building RESTful APIs with Laravel
• Following Laravel best practices and conventions

Target Agents

• laravel-expert - Primary user for Laravel development
• backend-developer - General backend development with Laravel
• api-architect - REST API design using Laravel

Core Patterns

1. MVC Architecture

Controller Pattern:

// Thin controllers, fat models
namespace App\Http\Controllers;

use App\Http\Requests\StorePostRequest;
use App\Services\PostService;

class PostController extends Controller
{
    public function __construct(
        private PostService $postService
    ) {}

    public function store(StorePostRequest $request)
    {
        $post = $this->postService->createPost($request->validated());

        return response()->json([
            'data' => $post,
            'message' => 'Post created successfully'
        ], 201);
    }
}

Service Layer Pattern:

namespace App\Services;

use App\Models\Post;
use App\Events\PostCreated;

class PostService
{
    public function createPost(array $data): Post
    {
        $post = Post::create($data);

        event(new PostCreated($post));

        return $post->load('author', 'tags');
    }
}

2. Eloquent ORM Best Practices

Relationship Definitions:

namespace App\Models;

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

class Post extends Model
{
    protected $fillable = ['title', 'content', 'user_id', 'status'];

    protected $casts = [
        'published_at' => 'datetime',
        'is_featured' => 'boolean',
    ];

    // Relationships
    public function author(): BelongsTo
    {
        return $this->belongsTo(User::class, 'user_id');
    }

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

    // Scopes
    public function scopePublished($query)
    {
        return $query->where('status', 'published')
                     ->whereNotNull('published_at');
    }

    // Accessors
    public function getExcerptAttribute(): string
    {
        return substr($this->content, 0, 200) . '...';
    }
}

Query Optimization:

// ❌ N+1 Problem
$posts = Post::all();
foreach ($posts as $post) {
    echo $post->author->name; // N+1 queries!
}

// ✅ Eager Loading
$posts = Post::with('author', 'comments.user')->get();

// ✅ Lazy Eager Loading
$posts = Post::all();
$posts->load('author', 'comments');

// ✅ Query Builder Optimization
$posts = Post::select(['id', 'title', 'user_id'])
    ->with(['author:id,name'])
    ->published()
    ->latest()
    ->paginate(15);

3. API Resources

Resource Classes:

namespace App\Http\Resources;

use Illuminate\Http\Resources\Json\JsonResource;

class PostResource extends JsonResource
{
    public function toArray($request): array
    {
        return [
            'id' => $this->id,
            'title' => $this->title,
            'excerpt' => $this->excerpt,
            'content' => $this->when($request->user()?->can('view', $this->resource), $this->content),
            'author' => new UserResource($this->whenLoaded('author')),
            'comments_count' => $this->when($this->comments_count !== null, $this->comments_count),
            'published_at' => $this->published_at?->toIso8601String(),
            'created_at' => $this->created_at->toIso8601String(),
            'links' => [
                'self' => route('posts.show', $this->id),
            ],
        ];
    }
}

Resource Collections:

namespace App\Http\Resources;

use Illuminate\Http\Resources\Json\ResourceCollection;

class PostCollection extends ResourceCollection
{
    public function toArray($request): array
    {
        return [
            'data' => $this->collection,
            'links' => [
                'self' => route('posts.index'),
            ],
            'meta' => [
                'total' => $this->total(),
                'current_page' => $this->currentPage(),
                'last_page' => $this->lastPage(),
            ],
        ];
    }
}

4. Authentication with Sanctum

API Token Authentication:

// config/sanctum.php
return [
    'expiration' => 60 * 24, // 24 hours
];

// Controller
use Laravel\Sanctum\HasApiTokens;

class AuthController extends Controller
{
    public function login(LoginRequest $request)
    {
        if (!Auth::attempt($request->only('email', 'password'))) {
            return response()->json(['message' => 'Invalid credentials'], 401);
        }

        $user = Auth::user();
        $token = $user->createToken('api-token')->plainTextToken;

        return response()->json([
            'user' => new UserResource($user),
            'token' => $token,
        ]);
    }

    public function logout(Request $request)
    {
        $request->user()->currentAccessToken()->delete();

        return response()->json(['message' => 'Logged out successfully']);
    }
}

5. Form Request Validation

Custom Request Classes:

namespace App\Http\Requests;

use Illuminate\Foundation\Http\FormRequest;
use Illuminate\Validation\Rule;

class StorePostRequest extends FormRequest
{
    public function authorize(): bool
    {
        return $this->user()->can('create', Post::class);
    }

    public function rules(): array
    {
        return [
            'title' => ['required', 'string', 'max:255'],
            'content' => ['required', 'string', 'min:100'],
            'status' => ['required', Rule::in(['draft', 'published'])],
            'tags' => ['array'],
            'tags.*' => ['exists:tags,id'],
            'published_at' => ['nullable', 'date', 'after:now'],
        ];
    }

    public function messages(): array
    {
        return [
            'content.min' => 'Post content must be at least 100 characters.',
            'tags.*.exists' => 'One or more selected tags do not exist.',
        ];
    }
}

6. Database Migrations

Migration Best Practices:

use Illuminate\Database\Migrations\Migration;
use Illuminate\Database\Schema\Blueprint;
use Illuminate\Support\Facades\Schema;

return new class extends Migration
{
    public function up(): void
    {
        Schema::create('posts', function (Blueprint $table) {
            $table->id();
            $table->foreignId('user_id')->constrained()->onDelete('cascade');
            $table->string('title');
            $table->string('slug')->unique();
            $table->text('content');
            $table->enum('status', ['draft', 'published'])->default('draft');
            $table->timestamp('published_at')->nullable();
            $table->timestamps();
            $table->softDeletes();

            // Indexes
            $table->index(['status', 'published_at']);
            $table->index('user_id');
        });
    }

    public function down(): void
    {
        Schema::dropIfExists('posts');
    }
};

7. Events and Listeners

Event-Driven Architecture:

// Event
namespace App\Events;

use App\Models\Post;
use Illuminate\Foundation\Events\Dispatchable;
use Illuminate\Queue\SerializesModels;

class PostCreated
{
    use Dispatchable, SerializesModels;

    public function __construct(public Post $post) {}
}

// Listener
namespace App\Listeners;

use App\Events\PostCreated;
use App\Notifications\NewPostNotification;

class NotifySubscribers
{
    public function handle(PostCreated $event): void
    {
        $subscribers = User::whereHas('subscriptions', function ($query) use ($event) {
            $query->where('user_id', $event->post->user_id);
        })->get();

        $subscribers->each(function ($subscriber) use ($event) {
            $subscriber->notify(new NewPostNotification($event->post));
        });
    }
}

8. Job Queues

Queueable Jobs:

namespace App\Jobs;

use App\Models\Post;
use Illuminate\Bus\Queueable;
use Illuminate\Contracts\Queue\ShouldQueue;
use Illuminate\Foundation\Bus\Dispatchable;
use Illuminate\Queue\InteractsWithQueue;
use Illuminate\Queue\SerializesModels;

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

    public $tries = 3;
    public $timeout = 120;

    public function __construct(
        public Post $post,
        public string $imagePath
    ) {}

    public function handle(): void
    {
        // Process image (resize, optimize, etc.)
        $processedPath = $this->processImage($this->imagePath);

        $this->post->update(['featured_image' => $processedPath]);
    }

    public function failed(\Throwable $exception): void
    {
        // Handle job failure
        \Log::error('Image processing failed', [
            'post_id' => $this->post->id,
            'error' => $exception->getMessage(),
        ]);
    }
}

9. Policy Authorization

Policy Classes:

namespace App\Policies;

use App\Models\Post;
use App\Models\User;

class PostPolicy
{
    public function viewAny(User $user): bool
    {
        return true;
    }

    public function view(?User $user, Post $post): bool
    {
        return $post->status === 'published' || $user?->id === $post->user_id;
    }

    public function create(User $user): bool
    {
        return $user->hasRole('author');
    }

    public function update(User $user, Post $post): bool
    {
        return $user->id === $post->user_id || $user->hasRole('admin');
    }

    public function delete(User $user, Post $post): bool
    {
        return $user->id === $post->user_id || $user->hasRole('admin');
    }
}

10. Testing

Feature Testing:

namespace Tests\Feature;

use App\Models\User;
use App\Models\Post;
use Illuminate\Foundation\Testing\RefreshDatabase;
use Tests\TestCase;

class PostControllerTest extends TestCase
{
    use RefreshDatabase;

    public function test_user_can_create_post(): void
    {
        $user = User::factory()->create();

        $response = $this->actingAs($user)
            ->postJson('/api/posts', [
                'title' => 'Test Post',
                'content' => 'This is a test post with enough content to pass validation.',
                'status' => 'draft',
            ]);

        $response->assertCreated()
            ->assertJsonStructure([
                'data' => ['id', 'title', 'content'],
                'message',
            ]);

        $this->assertDatabaseHas('posts', [
            'title' => 'Test Post',
            'user_id' => $user->id,
        ]);
    }
}

Project Structure

Recommended Laravel Project Structure:

app/
├── Console/
│   └── Commands/
├── Events/
├── Exceptions/
├── Http/
│   ├── Controllers/
│   │   └── Api/
│   ├── Middleware/
│   ├── Requests/
│   └── Resources/
├── Jobs/
├── Listeners/
├── Models/
├── Notifications/
├── Policies/
├── Providers/
└── Services/

Best Practices

1. Use Service Layer for complex business logic
2. Implement Repository Pattern for data access abstraction
3. Use Form Requests for validation
4. Apply Policy Classes for authorization
5. Leverage Events for decoupled architecture
6. Queue Long-Running Tasks with Laravel Jobs
7. Use API Resources for consistent API responses
8. Implement Proper Error Handling with custom exceptions
9. Write Tests (feature and unit tests)
10. Follow PSR Standards for code style

Additional Resources

For more advanced patterns, see:

• authentication.md - Advanced authentication patterns
• testing.md - Comprehensive testing strategies
• performance.md - Performance optimization techniques