What are Laravel controllers explain with detailed examples

2 years ago
Afaq Arif
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In Laravel, controllers are classes that handle the logic behind handling HTTP requests. They receive the incoming request, process it, and return an appropriate response. Controllers help to organize your application’s logic into separate, reusable components.

Here’s a detailed explanation of how to use controllers in a Laravel application with a detailed example:

Creating a Controller:
To create a controller in Laravel, you can use the make:controller Artisan command. For example, to create a UserController, run the following command:

php artisan make:controller UserController

This command will generate a UserController class under the app/Http/Controllers directory.

Defining Controller Methods:
Open the generated UserController class and define the methods that will handle specific actions related to user management. Each method represents a specific action that can be performed on a resource. For example:

<?php

namespace App\Http\Controllers;

use App\Models\User;
use Illuminate\Http\Request;

class UserController extends Controller
{
    public function index()
    {
        $users = User::all();

        return view('users.index', compact('users'));
    }

    public function show($id)
    {
        $user = User::findOrFail($id);

        return view('users.show', compact('user'));
    }

    public function store(Request $request)
    {
        // Validation and data processing logic here

        return redirect()->route('users.index')->with('success', 'User created successfully.');
    }

    public function update(Request $request, $id)
    {
        // Validation and data processing logic here

        return redirect()->route('users.show', $id)->with('success', 'User updated successfully.');
    }

    public function destroy($id)
    {
        $user = User::findOrFail($id);
        $user->delete();

        return redirect()->route('users.index')->with('success', 'User deleted successfully.');
    }
}

In this example, the UserController class defines methods such as index, show, store, update, and destroy to handle various actions related to user management. Each method contains the necessary logic to process the request, interact with the database or other services, and return an appropriate response.

Routing to Controllers:
To route requests to the corresponding controller methods, you can define routes in the routes/web.php file. For example:

use App\Http\Controllers\UserController;

Route::get('/users', [UserController::class, 'index'])->name('users.index');
Route::get('/users/{id}', [UserController::class, 'show'])->name('users.show');
Route::post('/users', [UserController::class, 'store'])->name('users.store');
Route::put('/users/{id}', [UserController::class, 'update'])->name('users.update');
Route::delete('/users/{id}', [UserController::class, 'destroy'])->name('users.destroy');

In this example, different HTTP methods (GET, POST, PUT, DELETE) are mapped to the corresponding controller methods. The UserController class is referenced using the ::class syntax, and the method names are provided as strings.

Passing Data to Views:
In the controller methods, you can pass data to views by using the view function and the compact function. For example, in the index method:

public function index()
{
    $users = User::all();

    return view('users.index', compact('users'));
}

In this example, the users.index view is rendered, and the $users variable is passed to the view using the compact function.

Defining Views:
Create the corresponding view files to display the data returned by the controller methods. For example, create index.blade.php, show.blade.php, and other view files under the resources/views/users directory. These view files will contain HTML and Blade syntax to display the data.
Accessing Controllers from Views:
You can also access controller actions from views to generate URLs. For example, in a view, you can use the route helper function to generate a URL to a specific controller method. For example:

<a href="{{ route('users.show', $user->id) }}">View User</a>

In this example, the route function generates a URL to the show method of the UserController with the appropriate user ID.

By using controllers in Laravel, you can separate the logic of handling HTTP requests into separate classes, making your code more organized, reusable, and maintainable. Controllers help in keeping your routes clean and focused on defining routes without cluttering them with complex logic.