What is Middleware in Laravel?

In Laravel, middleware acts as a bridge between a request and a response.It filter the HTTP requests before entering your application.

You can imagine middleware as a security guard.

Before a request reaches your controller, middleware checks condition like:

• Is the User Logged in (Authenticated)?
• Does the user have admin access?
• From where the request is coming (from a specific IP)?

Laravel provides built-in middleware like authentication and CSRF, and it also allows you to create custom middleware.

Artisan Command for creating Middleware:

php artisan make:middleware MiddlewareName

Example: php artisan make:middleware AgeCheck

Types of Middleware:

Laravel middlewares can be categorized into:

1. Global Middleware
2. Route Middleware (single middleware)
3. Groups Middleware
4. Parameterized Middleware

 1. Global Middleware:

Global middleware runs on every request.

How to Register Global Middleware (Laravel 11+)

1. Create a middleware using the artisan command.
2. open 

   bootstrap/app.php

3. Add indesite withMiddleware():

   /**
   * import path important
   * midlewares are stored in App\Http\Middleware
   */
   use App\Http\Middleware\AgeCheck;
   
   ->withMiddleware(function (Middleware $middleware) {
       $middleware->append(AgeCheck::class);
   });
   
   

When to use Global Middleware?

• Logging requests
• Maintenance mode checks
• security headers
• Application-wide validation

 2. Route Middleware(Single):

Route middleware is applied to specific routes.

Step # 01  ( Create Middleware )

php artisan make:middleware CheckAge

This creates:

app/Http/Middleware/CheckAge.php

Step # 02  ( Write Logic )

namespace App\Http\Middleware;

use Closure;
use Illuminate\Http\Request;

class CheckAge
{
    public function handle(Request $request, Closure $next)
    {
        if ($request->age < 18) {
            return response("You are not allowed.", 403);
        }

        return $next($request);
    }
}

Step # 03  ( Register Alias )

go to bootstrap/app.php 

->withMiddleware(function (Middleware $middleware) {

    $middleware->alias([
        'checkage' => \App\Http\Middleware\CheckAge::class,
    ]);

})

Step # 04  ( Apply to Route )

In routes/web.php

use Illuminate\Support\Facades\Route;

Route::get('/restricted', function () {
    return "Access Granted";
})->middleware('checkage');

3. Group Middleware

4. Parameterized Middleware