Laravel Middleware Explained

Middleware provide a convenient mechanism for inspecting and filtering HTTP requests entering your application. For example, Laravel includes middleware that verifies the user of your application is authenticated.

#Creating Middleware

Middleware classes typically reside in the app/Http/Middleware directory. You can generate a new middleware using the Artisan command:

php artisan make:middleware EnsureTokenIsValid

Inside the middleware’s handle method, you implement your filtering logic. You can either pass the request deeper into the application or return a response directly.

public function handle(Request $request, Closure $next)
{
    if ($request->input('token') !== 'my-secret-token') {
        return redirect('home');
    }

    return $next($request);
}

#Registering & Assigning Middleware

Before you can use middleware, you need to register it in app/Http/Kernel.php. Middleware can be registered globally (to run on every request), assigned to route groups, or assigned to specific routes.

// Assigning middleware to a route
Route::get('/profile', function () {
    //
})->middleware(EnsureTokenIsValid::class);

// Assigning middleware to a group
Route::middleware([EnsureTokenIsValid::class])->group(function () {
    Route::get('/', function () { ... });
    Route::get('/user/profile', function () { ... });
});

Middleware can perform tasks like authentication, logging, CORS handling, or modifying the incoming request before it reaches your route or controller.