Laravel Middleware

What is Middleware

In Laravel, Middleware is the mechanism to apply any type of filtering you may need to HTTP requests to your application.

Middleware works between request and response of our application.It sits between Request and Response like a firewall that examine whether to route a request.Laravel comes with several inbuilt middlewares like EncryptCookies ,RedirectIfAuthenticated,TrimStrings,TrustProxies etc .

All middleware in Laravel are created in the Middleware folder, located inside the app/HTTP folder.

A few things I could think of that you could achieve through middleware are:

• logging of requests
• redirecting users
• altering/sanitizing the incoming parameters
• manipulating the response generated by the Laravel application
• and many more

Creating Middleware

We can easily create new middleware using artisan.

php artisan make:middleware AdMiddleware

After we’ve created a new middleware component, we then need to look at modifying the code to suit our needs.

Updating our Middleware File:

After you’ve ran the make:middleware command you should see your new middleware file in app/http/middleware. Open this up and we’ll create a middleware that will get the request’s IP address and then determine what country that request came from.

<?php 
namespace App\Http\Middleware;
use Closure;
class AdMiddleware
{
  /**
    * Handle an incoming request.
    *
    * @param  \Illuminate\Http\Request  $request
    * @param  \Closure  $next
    * @return mixed
    */
  public function handle($request, Closure $next)
  {
    // Test to see if the requesters have an ip address.
    if($request->ip() == null){
        throw new \Exception("IP ADDRESS NOT SET");   
    } 
    $country=file_get_contents('http://api.hostip.info/get_html.php?ip=' . $request->ip());
    echo $country;
    if(strpos($country, "UNITED STATES")){
        throw new \Exception("NOT FOR YOUR EYES, NSA");   
    } else {
        return redirect("index");   
    }
    
    return $next($request);
  }
}

This code basically takes in a request and as an example checks to see it’s location before deciding whether to display a US only ad or an advertisement suited for the rest of the world. This could be quite beneficial for those of you who want to build up a site that features amazon affiliate links from multiple countries.

Note that you shouldn’t be passing anything back in the middleware section, you should instead be passing redirects to views instead of printing out things like I’ve done for brevity.

Registering your Middleware

When registering your middleware you have 2 choices. First choice is that you add the middleware to be run on every request handled by your app. You can do that by opening up App\Http\Kernel.php and adding it to your $middleware array like so:

protected $middleware = [
  \Illuminate\Foundation\Http\Middleware\CheckForMaintenanceMode::class,
  \App\Http\Middleware\EncryptCookies::class,
  \Illuminate\Cookie\Middleware\AddQueuedCookiesToResponse::class,
  \Illuminate\Session\Middleware\StartSession::class,
  \Illuminate\View\Middleware\ShareErrorsFromSession::class,
  \App\Http\Middleware\VerifyCsrfToken::class,
// our new class.
  \App\http\Middleware\AdMiddleware::class,
];

Second choice is to have the middleware run on registered routes only, you can register it like so:

<?php
/**
  * The application's route middleware.
  *
  * @var array
  */
protected $routeMiddleware = [
    'auth' => \App\Http\Middleware\Authenticate::class,
    'auth.basic' => \Illuminate\Auth\Middleware\AuthenticateWithBasicAuth::class,
    'guest' => \App\Http\Middleware\RedirectIfAuthenticated::class,
    'ad' => \App\Http\Middleware\AdMiddleware::class,
];

And then add the middleware to the specific routes like so:

Route::get('/ip', ['middleware' => 'ad', function() {
    return "IP";
}]);

Thanks!