Application Controller Pattern

1. Introduction

The Application Controller Pattern is a design pattern used in software engineering to separate the control logic from the presentation layer. This pattern is particularly useful in web applications where multiple requests need to be handled efficiently.

2. Key Concepts

• Separation of Concerns: The Application Controller manages the flow of the application, while the view handles presentation and user interaction.
• Single Entry Point: All requests are routed through a central controller, simplifying the request handling process.
• Extensibility: New features can be added with minimal changes to existing code.

3. Implementation

The following steps outline the implementation of the Application Controller Pattern:

1. Create an Application Controller class that will handle incoming requests.
2. Define methods for handling different types of requests (e.g., GET, POST).
3. Use the controller to invoke the appropriate view based on the request.

Example Code

class ApplicationController {
    public function handleRequest($request) {
        switch ($request->getType()) {
            case 'GET':
                $this->handleGet($request);
                break;
            case 'POST':
                $this->handlePost($request);
                break;
            default:
                $this->handleDefault($request);
                break;
        }
    }

    private function handleGet($request) {
        // logic for handling GET requests
    }

    private function handlePost($request) {
        // logic for handling POST requests
    }

    private function handleDefault($request) {
        // logic for handling default requests
    }
}
                

4. Best Practices

• Keep Controllers Lightweight: Avoid placing too much logic in the controller; delegate responsibilities to services or models.
• Use Dependency Injection: This allows for greater flexibility and easier testing.
• Maintain Clear Routing: Ensure that the routing to the controller methods is clear and consistent.

5. FAQ