How to write a controller in laravel

Laravel is a modern PHP web development framework that provides many excellent features and tools to enable developers to quickly build high-quality web applications. The controller is one of the most important components in Laravel, which is responsible for handling the business logic of the application. Let’s talk about how to write controllers in Laravel.

1. Create a controller

In Laravel, creating a controller is very simple, just enter the following command on the console:

php artisan make:controller YourControllerName

where YourControllerName is the name of the controller you want to create.

2. Writing controller code

The controller code is usually located in the app/Http/Controllers directory. Open the controller file you just created and you will see the following code:

<?php namespace App\Http\Controllers;

use Illuminate\Http\Request;

class YourControllerName extends Controller
{
    //
}

Where namespace is the namespace and use is the reference class. Inherited the Controller class, which is the parent class of the Laravel controller and provides us with many default methods, such as view(), json(), redirect(), etc.

Now, we can start writing our own controller code. As a simple example, let's say we want to use a controller to find and display user information. Then we can add the following code to the controller class:

public function show($id)
{
    $user = User::find($id);
    return view('users.show', ['user' => $user]);
}

In this code, we define a method called show() and pass in the id parameter from the URL. Then we use the User::find($id) method to query the user information corresponding to the id, and finally use the View() method to pass the relevant user information to the view file (the file is located in resources/views/users/show.blade.php) .

3. Route Definition

Now we have defined the controller and related business logic code. We need to let the Laravel application know how to access this controller, which can be achieved through a route definition.

In Laravel, route definitions are usually located in the routes/web.php file. We can add the following code to the file:

Route::get('users/{id}', 'YourControllerName@show');

This code defines a route named show that will match URLs starting with /users and pass the id parameter to the controller's show() method.

4. Testing

Now that we have completed writing the controller code and defining the routes, let us test our controller.

Start the development server on the console:

php artisan serve

Then visit in your browser:

http://localhost:8000/users/1

You will see a page showing the user with id 1 information. At this point, we have successfully created and used a Laravel controller.

Summary:

• Use the command line to quickly create a Laravel controller.
• Write controller logic code to implement business logic.
• Specify the controller method in the route definition to access the controller.
• Test in the browser whether the controller is working properly.

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