All 7 MVC Architecture in PHP questions
More in MVC Architecture in PHP
What is the MVC architectural pattern, and how do the Model, View, and Controller components each play a distinct role in a PHP application? How do Models in MVC represent both data structure and business logic, and how does this differ from a Model being purely a simple database representation? How do Views in MVC separate presentation logic from application logic, and what role do templating engines like Blade play in this separation? How does a typical request flow through an MVC based PHP application, from the initial incoming HTTP request to the final rendered response? How does the concept of a Service Layer complement traditional MVC by providing an additional place for complex business logic that spans multiple models? How should a large, complex PHP application evolve its architecture beyond basic MVC to maintain organization and testability as the codebase and team grow significantly?
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What is the role of a Controller in the MVC pattern, and what responsibilities should typically be kept out of a controller to maintain good separation of concerns?

Beginner

Answer

A controller's primary responsibility is to receive an incoming request, coordinate with the appropriate model to retrieve or modify data, and determine which view should be rendered as a response, and it should generally avoid containing significant business logic itself, such as complex calculations or validation rules, which properly belong in dedicated model classes or separate service classes, keeping controllers thin and focused purely on request handling and coordination.
class OrderController {
    public function store(Request $request) {
        $order = $this->orderService->createOrder($request->validated());
        return redirect()->route('orders.show', $order);
    }
}
Real-world example An order processing controller delegates the actual complex order creation logic, including inventory checks and payment processing, to a dedicated OrderService class, keeping the controller itself simple and focused purely on handling the incoming request and returning an appropriate response.

Common follow-ups: What is a 'fat controller' and why is it generally considered a code smell?;Where should complex business logic ideally live if not directly in the controller?

Dependency Injection & Service Containers;Design Patterns in PHP
All 7 MVC Architecture in PHP questions