Laravel Middleware

Table of Contents

1. Defining Middleware

2. Registering Middleware

3. Middleware Parameters

4. Terminable Middleware

1. Defining Middleware

Middleware acts as an intermediary between a request and a response. For example, if a user is not authenticated, the application may redirect them from login.php to index.php.

You can create middleware using the following command:

php artisan make:middleware <MiddlewareName>

Replace <MiddlewareName> with your desired name. The created middleware will be stored in app/Http/Middleware/.

Example:

php artisan make:middleware CheckUser

2. Registering Middleware

Before using any middleware, you must register it in your Laravel application.

Laravel provides two types of middleware:

• Global Middleware: Runs on every HTTP request.

• Route Middleware: Applies only to specific routes.

Global Middleware

Global middleware is listed in the $middleware property of app/Http/Kernel.php.

Route Middleware

Route middleware is defined in the $routeMiddleware array of app/Http/Kernel.php. To add custom middleware, append it to this list with a key of your choice.

Example:

protected $routeMiddleware = [
   'auth' => \Illuminate\Auth\Middleware\Authenticate::class,
   'auth.basic' => \Illuminate\Auth\Middleware\AuthenticateWithBasicAuth::class,
   'guest' => \App\Http\Middleware\RedirectIfAuthenticated::class,
   'userAuth' => \Illuminate\Routing\Middleware\UserAuthRequests::class,
];

3. Middleware Parameters

Middleware can accept parameters to handle different roles such as customer, employee, admin, or owner.

Example:

public function handle($request, Closure $next, $profile)
{
    if (! $request->user()->hasProfile($profile)) {
        // Redirect or handle unauthorized access
    }
    return $next($request);
}

To create a middleware that handles user profiles, run:

php artisan make:middleware ProfileMiddleware

The new middleware will be located in app/Http/Middleware/ProfileMiddleware.php.

Example:

<?php

namespace App\Http\Middleware;
use Closure;

class ProfileMiddleware {
    public function handle($request, Closure $next, $profile) {
        echo "Role: " . $profile;
        return $next($request);
    }
}

4. Terminable Middleware

Terminable middleware executes tasks after a response is sent to the browser. This is achieved using the terminate method.

Example:

<?php

namespace Illuminate\Session\Middleware;
use Closure;

class SessionBegin
{
    public function handle($request, Closure $next)
    {
        return $next($request);
    }
    
    public function terminate($request, $response)
    {
        // Perform post-response tasks
    }
}