Web20 University

Learn PHP MVC: A Comprehensive Guide with Detailed Examples

Get Up to 65% Off PHP Hosting and Free Domains!

The Model-View-Controller (MVC) architecture is a popular design pattern used in web development to separate concerns and improve code organization. Learning PHP MVC can help you build scalable, maintainable web applications. This guide will introduce you to the MVC pattern and show you how to implement it in PHP with detailed examples.

What is MVC?

MVC stands for Model-View-Controller. It divides an application into three interconnected components:

  • Model: Represents the data and business logic.
  • View: Displays the data (user interface).
  • Controller: Handles user input and interacts with the model to update the view.

Why Use MVC?

  1. Separation of Concerns: Each component has a distinct responsibility, making the code easier to manage and understand.
  2. Reusability: Code can be reused across different parts of the application.
  3. Maintainability: Changes in one component have minimal impact on others, simplifying maintenance.

Setting Up a Basic PHP MVC Framework

Let’s build a simple PHP MVC framework from scratch. We’ll create a basic web application that manages a list of users.

Step 1: Directory Structure

First, set up the directory structure for the MVC application:

myapp/
│
├── app/
│   ├── controllers/
│   │   └── UserController.php
│   ├── models/
│   │   └── User.php
│   └── views/
│       └── users/
│           ├── index.php
│           └── show.php
│
├── public/
│   ├── index.php
│   └── .htaccess
│
├── core/
│   ├── App.php
│   ├── Controller.php
│   └── Model.php
│
└── config/
    └── config.php

Step 2: Configuration

Create the configuration file config/config.php to define database connection details:

<?php
define('DB_HOST', 'localhost');
define('DB_USER', 'root');
define('DB_PASS', '');
define('DB_NAME', 'mvc_example');
?>

Step 3: Core Components

Create core components to handle routing, base controller, and base model.

core/App.php:

<?php

class App {
    protected $controller = 'UserController';
    protected $method = 'index';
    protected $params = [];

    public function __construct() {
        $url = $this->parseUrl();

        if (file_exists('../app/controllers/' . $url[0] . '.php')) {
            $this->controller = $url[0];
            unset($url[0]);
        }

        require_once '../app/controllers/' . $this->controller . '.php';
        $this->controller = new $this->controller;

        if (isset($url[1])) {
            if (method_exists($this->controller, $url[1])) {
                $this->method = $url[1];
                unset($url[1]);
            }
        }

        $this->params = $url ? array_values($url) : [];

        call_user_func_array([$this->controller, $this->method], $this->params);
    }

    public function parseUrl() {
        if (isset($_GET['url'])) {
            return explode('/', filter_var(rtrim($_GET['url'], '/'), FILTER_SANITIZE_URL));
        }
    }
}
?>

core/Controller.php:

<?php

class Controller {
    public function model($model) {
        require_once '../app/models/' . $model . '.php';
        return new $model();
    }

    public function view($view, $data = []) {
        require_once '../app/views/' . $view . '.php';
    }
}
?>

core/Model.php:

<?php

class Model {
    protected $db;

    public function __construct() {
        $this->db = new PDO('mysql:host=' . DB_HOST . ';dbname=' . DB_NAME, DB_USER, DB_PASS);
    }
}
?>

Step 4: Public Entry Point

Create the public entry point public/index.php:

<?php

require_once '../config/config.php';
require_once '../core/App.php';
require_once '../core/Controller.php';
require_once '../core/Model.php';

$app = new App();
?>

Step 5: .htaccess for URL Rewriting

Create the .htaccess file in the public directory for URL rewriting:

RewriteEngine On
RewriteCond %{REQUEST_FILENAME} !-f
RewriteCond %{REQUEST_FILENAME} !-d
RewriteRule ^(.+)$ index.php?url=$1 [QSA,L]

Step 6: Creating the Model

Create the User model in app/models/User.php:

<?php

class User extends Model {
    public function getAllUsers() {
        $stmt = $this->db->query("SELECT * FROM users");
        return $stmt->fetchAll(PDO::FETCH_ASSOC);
    }

    public function getUserById($id) {
        $stmt = $this->db->prepare("SELECT * FROM users WHERE id = :id");
        $stmt->bindParam(':id', $id);
        $stmt->execute();
        return $stmt->fetch(PDO::FETCH_ASSOC);
    }
}
?>

Step 7: Creating the Controller

Create the UserController in app/controllers/UserController.php:

<?php

class UserController extends Controller {
    public function index() {
        $userModel = $this->model('User');
        $users = $userModel->getAllUsers();
        $this->view('users/index', ['users' => $users]);
    }

    public function show($id) {
        $userModel = $this->model('User');
        $user = $userModel->getUserById($id);
        $this->view('users/show', ['user' => $user]);
    }
}
?>

Step 8: Creating the Views

Create the index view in app/views/users/index.php:

<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <title>Users List</title>
</head>
<body>
    <h1>Users List</h1>
    <ul>
        <?php foreach ($data['users'] as $user): ?>
            <li>
                <a href="/user/show/<?php echo $user['id']; ?>">
                    <?php echo $user['name']; ?>
                </a>
            </li>
        <?php endforeach; ?>
    </ul>
</body>
</html>

Create the show view in app/views/users/show.php:

<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <title>User Details</title>
</head>
<body>
    <h1>User Details</h1>
    <p>Name: <?php echo $data['user']['name']; ?></p>
    <p>Email: <?php echo $data['user']['email']; ?></p>
    <p>Age: <?php echo $data['user']['age']; ?></p>
</body>
</html>

Conclusion

In this guide, we’ve covered the basics of the MVC pattern and how to implement it in PHP. We set up a basic PHP MVC framework and created a simple application to manage a list of users. This architecture helps in organizing your code better, making it more maintainable and scalable.

By following these steps, you can build more complex applications using the MVC pattern, which is a fundamental skill for any web developer. Continue exploring and expanding your application by adding more features and improving the structure.

Further Reading

By understanding and implementing the MVC pattern in PHP, you’ll be well-equipped to build robust and scalable web applications.

Get Up to 65% Off PHP Hosting and Free Domains!