What is the Repository Pattern in Laravel

What is the Repository Pattern in Laravel

The Repository Pattern in Laravel is a design pattern used to abstract the data layer, allowing you to decouple your application from the persistence layer (e.g., Eloquent ORM, Query Builder, or an external API). It acts as a mediator between your controllers and your models, making your code more testable, flexible, and maintainable.

Why Use the Repository Pattern?

1. Swappable data sources – Easily switch from Eloquent to an external API or another database layer.
2. Better unit testing – Mocks can be injected into the repository interface.
3. Cleaner, more organized code

When to Use the Repository Pattern

• Repetitive queries across controllers:

  Centralizes queries so you write once, reuse everywhere.

• Unit testing needed:

  Allows easy mocking/stubbing of data access logic.

• Switching data sources:

  You can change from Eloquent to API/Redis without touching controller code.

• Large-scale applications:

  Helps organize codebase using SOLID and DDD principles.

When Not to Use It

• Simple CRUD apps
• No testing needs
• Prototype or MVP

Use the repository pattern when you find yourself repeating queries, writing complex logic in controllers, or planning for growth/testing.

Common Use Cases

• E-commerce systems – complex product, cart, and order logic.
• Learning management systems (LMS) – many relationships between students, courses, quizzes, etc.
• APIs – where you want clear separation between the API logic and the DB access.
• Microservices – to isolate data layer behind contracts (interfaces).

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EXAMPLE

1. Create an Interface

// app/Repositories/PostRepositoryInterface.php

namespace App\Repositories;

interface PostRepositoryInterface
{
    public function all();
    public function find($id);
    public function create(array $data);
    public function update($id, array $data);
    public function delete($id);
}

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2. Create the Repository Implementation

// app/Repositories/PostRepository.php

namespace App\Repositories;

use App\Models\Post;

class PostRepository implements PostRepositoryInterface
{
    public function all()
    {
        return Post::all();
    }

    public function find($id)
    {
        return Post::findOrFail($id);
    }

    public function create(array $data)
    {
        return Post::create($data);
    }

    public function update($id, array $data)
    {
        $post = Post::findOrFail($id);
        $post->update($data);
        return $post;
    }

    public function delete($id)
    {
        $post = Post::findOrFail($id);
        return $post->delete();
    }
}

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3. Bind the Interface to the Implementation

In App\Providers\AppServiceProvider or a custom service provider:

use App\Repositories\PostRepository;
use App\Repositories\PostRepositoryInterface;

public function register()
{
    $this->app->bind(PostRepositoryInterface::class, PostRepository::class);
}

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4. Use It in a Controller

use App\Repositories\PostRepositoryInterface;

class PostController extends Controller
{
    protected $postRepo;

    public function __construct(PostRepositoryInterface $postRepo)
    {
        $this->postRepo = $postRepo;
    }

    public function index()
    {
        $posts = $this->postRepo->all();
        return view('posts.index', compact('posts'));
    }
}

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✅ Benefits in Practice

• Helps with unit testing (you can mock PostRepositoryInterface).
• Makes your code follow SOLID principles (especially the Dependency Inversion Principle).
• Makes it easier to refactor your data source later.