MVC.md

Model-View-Controller (MVC)

MVC separates application logic into three components: Model, View, and Controller.

Components:

• Model: Manages data, business logic, and state.
• View: Displays data to the user (UI components).
• Controller: Handles user input, interacts with model, updates view.

Interaction Flow:

User → Controller → Model → View → User

Pros:

• Clear separation of concerns.
• Easier testing and maintenance.

Cons:

• Controller can become overly complex.
• Can lead to tight coupling between Controller and View.

When to use:

• Web applications (e.g., Django, Ruby on Rails).
• Applications where UI and logic are clearly separated.

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5. Onion Architecture

Similar to Clean Architecture; it's layered, focused on decoupling external dependencies from core logic.

Layers:

• Domain Layer: Core domain logic and entities.
• Application Services Layer: Use cases and business logic orchestration.
• Infrastructure Layer: External resources (database, file system, etc.).
• Presentation/UI Layer: User interfaces and controllers.

Structure:

Presentation/UI → Application Services → Domain ← Infrastructure

Pros:

• Strong decoupling and testability.
• Easier to maintain domain purity.

Cons:

• Requires clear discipline to avoid domain pollution.
• Can be overly structured for simpler apps.

When to use:

• Complex applications with evolving business logic.
• Enterprise apps with strong domain models.