Front Controller Pattern

Introduction

The Front Controller Pattern is a design pattern used in web applications to provide a centralized entry point for handling requests. It simplifies the management of requests by routing them to the appropriate handlers, promoting a cleaner architecture.

Key Concepts

• Centralized Request Handling: All incoming requests are processed by a single controller.
• Separation of Concerns: Business logic is separated from presentation logic, enhancing maintainability.
• Single Entry Point: Reduces the number of entry points in the application, simplifying routing.
• Flexibility: New functionalities can be added without modifying existing code significantly.

Implementation

To implement the Front Controller Pattern, follow these steps:

1. Create a Front Controller class that will handle incoming requests.
2. Define a Router class to map URLs to specific handlers.
3. Implement various handler classes to process requests and generate responses.
4. Integrate the Front Controller with the web server to route requests.

Code Example

class FrontController {
    public function handleRequest($request) {
        $router = new Router();
        $handler = $router->getHandler($request);
        $handler->handle();
    }
}

class Router {
    public function getHandler($request) {
        // Logic to determine the appropriate handler based on the request
        return new SomeHandler(); // Example
    }
}

class SomeHandler {
    public function handle() {
        echo "Handling request!";
    }
}

// Usage
$frontController = new FrontController();
$frontController->handleRequest($_SERVER['REQUEST_URI']);

Best Practices

When implementing the Front Controller Pattern, consider the following best practices:

• Keep your Front Controller lightweight; delegate complex logic to specialized handlers.
• Ensure clear routing rules to avoid conflicts and ambiguities.
• Utilize middleware for cross-cutting concerns like authentication and logging.
• Document routing configurations and handler responsibilities thoroughly.

FAQ