Frameworks (Laravel, Symfony, etc.)

Web development frameworks are software frameworks designed to support the development of web applications including web services, web resources, and web APIs. They provide a standard way to build and deploy web applications by offering a structured foundation, reusable components, and pre-built functionalities. The goal is to reduce repetitive coding, improve development speed, enforce best practices, and enhance the security and maintainability of applications.

Why use Frameworks?
* Speed and Efficiency: Frameworks provide a base structure and common functionalities (like authentication, database interaction, routing) out-of-the-box, significantly reducing development time.
* Structure and Organization: They promote organized code using design patterns like Model-View-Controller (MVC), making applications easier to understand, maintain, and scale.
* Security: Frameworks often include built-in features to protect against common web vulnerabilities (e.g., SQL injection, CSRF, XSS).
* Maintainability: Adherence to a standard structure and conventions makes it easier for multiple developers to work on a project and for new developers to onboard.
* Community and Ecosystem: Popular frameworks have large communities, extensive documentation, and a rich ecosystem of third-party packages and tools, providing ample support and resources.

Common Features of Frameworks:
* Routing: Mapping URLs to specific actions or controllers.
* Database Abstraction / ORM (Object-Relational Mapping): Simplifying database interactions by allowing developers to work with objects instead of raw SQL queries (e.g., Eloquent in Laravel, Doctrine in Symfony).
* Templating Engines: Tools for generating dynamic HTML content (e.g., Blade in Laravel, Twig in Symfony).
* Authentication and Authorization: Handling user login, registration, and permission management.
* Caching: Improving application performance by storing frequently accessed data.
* Testing Tools: Built-in support for unit, integration, and feature testing.
* Command Line Interface (CLI): Tools for common development tasks (e.g., `artisan` in Laravel, `bin/console` in Symfony).

Popular PHP Frameworks:
* Laravel: Known for its elegant syntax, developer-friendly features, and robust ecosystem. It simplifies complex tasks and offers a rapid development experience.
* Symfony: A highly modular and flexible framework, often chosen for large-scale enterprise applications. It's known for its stability, performance, and extensive set of reusable components (many of which Laravel also uses).
* CodeIgniter: Lightweight and simple, good for beginners or smaller projects.
* Yii: A high-performance framework suitable for developing large-scale web applications.
* Laminas (formerly Zend Framework): An enterprise-grade framework, very flexible but with a steeper learning curve.

Laravel vs. Symfony (Brief comparison):
While both are powerful PHP frameworks, Laravel is often praised for its ease of use, extensive out-of-the-box features, and a focus on developer experience. Symfony, on the other hand, is known for its highly modular architecture, performance, and flexibility, making it a strong choice for complex, custom applications where every component needs to be precisely controlled. Many Laravel components are built on top of Symfony components.

<?php

// --- 1. Routing (simulated web.php in Laravel) ---
// This file defines how incoming requests are handled.
// In a real Laravel app, this would be in 'routes/web.php'.

// Imagine a web server configured to direct all requests through a front controller (index.php)
// and this routing logic is executed there.

// A simple dispatcher that maps URLs to controller actions
function dispatchRoute($uri) {
    // Remove query string and trim slashes
    $uri = strtok($uri, '?');
    $uri = trim($uri, '/');

    switch ($uri) {
        case '': // Home page
            // In a real framework, 'app\\controllers\\HomeController' would be auto-loaded.
            return app\\controllers\\HomeController::index();
        case 'products':
            return app\\controllers\\ProductController::listProducts();
        case 'products/add':
            return app\\controllers\\ProductController::addProduct();
        default:
            http_response_code(404);
            return "404 Not Found";
    }
}

// --- 2. Controllers (simulated app/Http/Controllers in Laravel) ---
// Controllers contain the application logic for specific parts of the application.

namespace app\\controllers; // Using namespaces as frameworks do

class HomeController
{
    public static function index()
    {
        // In a real framework, this would typically render a view using a templating engine.
        return "Welcome to the Home Page!";
    }
}

class ProductController
{
    public static function listProducts()
    {
        $products = [
            ['id' => 1, 'name' => 'Laptop', 'price' => 1200],
            ['id' => 2, 'name' => 'Mouse', 'price' => 25],
        ];
        // Imagine fetching from a database via an ORM and passing to a view.
        $output = "<h1>Our Products</h1><ul>";
        foreach ($products as $product) {
            $output .= "<li>{$product['name']} - $" . number_format($product['price'], 2) . "</li>";
        }
        $output .= "</ul>";
        return $output;
    }

    public static function addProduct()
    {
        // In a real framework, this would handle form submission, validation,
        // and saving to a database. For simplicity, just a message.
        return "Form to add a new product would be here.";
    }
}


// --- 3. Front Controller (simulated public/index.php in Laravel) ---
// All web requests go through this file. It bootstraps the application
// and dispatches the request to the appropriate route/controller.

// This part would be in public/index.php in a real Laravel setup.
// For this standalone example, we just call the dispatcher directly.
echo dispatchRoute($_SERVER['REQUEST_URI']);

// To run this example:
// 1. Save the code as `framework_example.php`.
// 2. Open your terminal in the directory where you saved the file.
// 3. Start PHP's built-in web server: `php -S localhost:8000 framework_example.php`
// 4. Open your web browser and navigate to:
//    - http://localhost:8000/ (for the home page)
//    - http://localhost:8000/products (to list products)
//    - http://localhost:8000/products/add (to simulate adding a product)
//    - http://localhost:8000/nonexistent (to see the 404 handler)