Laravel development: How to use Laravel Middleware?

As a popular PHP framework, Laravel often uses Middleware middleware during the development process. In this article, we will cover the basics of using Laravel middleware and how to create and use custom Middleware.

Laravel Middleware Middleware is a mechanism for filtering HTTP requests. They are often used to handle complex HTTP request logic, such as authenticating users, granting access, or logging requests.

Laravel comes with some built-in Middleware, such as:

• auth: used to check whether the user is logged in.
• throttle: Used to limit the number of requests a user can make within a certain period of time.

In this article, we will use Laravel's own Middleware middleware to demonstrate these basic concepts. Additionally, we will create a custom Middleware to demonstrate how to write your own middleware.

Using built-in Middleware

Let us first take a look at how to use built-in Middleware in Laravel. To use the built-in middleware, you just need to add it to the $routeMiddleware array. In the appHttpKernel.php file, this array can be found. This array contains all default middleware, and each middleware has a key associated with it.

For example, we can enable authentication middleware by using the auth key name:

protected $routeMiddleware = [
    'auth' => IlluminateAuthMiddlewareAuthenticate::class,
];

Laravel also supports parameterized passing of middleware. For example, if we want to use throttle to limit users to access up to 5 pages within 60 seconds, we can write:

protected $routeMiddleware = [
    'throttle' => IlluminateRoutingMiddlewareThrottleRequests::class.':5,60',
];

Note: The order of the numbers here is opposite to the order of parameters of the throttle middleware constructor. This is because Laravel supports passing parameters as strings.

Create custom Middleware

In addition to using pre-defined Middleware, Laravel also supports creating your own middleware. Let's take a look at how to create and use custom Middleware.

To demonstrate this, we will create a custom middleware called MyMiddleware. This middleware only needs to output the text before the request is processed.

First, we need to create a middleware class through the artisan command:

php artisan make:middleware MyMiddleware

Then, we need to open the app/Http/Middleware/MyMiddleware.php file and write our Middleware logic:

<?php

namespace AppHttpMiddleware;

use Closure;

class MyMiddleware
{
    public function handle($request, Closure $next)
    {
        echo "My middleware is working!";
        return $next($request);
    }
}

In this example, we only need to output a text before processing the request. This text can be anything, for example you can output some debugging information, logs or error messages, etc.

After writing our Middleware, we need to register it with the Laravel application. In the app/Http/Kernel.php file, we can add our middleware class name to the $routeMiddleware array. This will make the middleware available to routes and controllers.

protected $routeMiddleware = [
    'mymiddleware' => AppHttpMiddlewareMyMiddleware::class,
];

Note: As you can see, we use the name of the MyMiddleware class as a key name for use in subsequent routes and controllers.

To use this new middleware, just add it to the middleware array as usual. In our case, we can add this to the website's routes:

Route::middleware(['mymiddleware'])->group(function () {
    // Your routes here
});

Now, when we receive a request from our application, our middleware will be called first, and then Request processing.

Summary

In this article, we have discussed the basics of Middleware in Laravel and demonstrated how to use Laravel's built-in middleware and how to create and Use custom Middleware middleware. This is just a simple example, the concept of middleware is very important, they can be used to solve many complex problems of handling HTTP requests. Therefore, learning how to use Middleware is a very important step in the Laravel development process.

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