Hexagonal Architecture (Ports & Adapters)

Hexagonal Architecture, also known as Ports and Adapters, is a software architectural pattern that aims to isolate the core logic of an application from external concerns such as user interfaces, databases, and third-party services.

• Ports: Interfaces that define how the core application interacts with the outside world.
• Adapters: Implementations of ports that allow communication between the application and external systems.
• Core Domain: The business logic that is independent of external systems.

The Hexagonal Architecture can be visualized as follows:

graph TD;
                A[Core Domain] -->|Port| B[Adapter 1];
                A -->|Port| C[Adapter 2];
                D[External Systems] -->|Adapter| B;
                D -->|Adapter| C;
            

Here's a simple implementation example in Python:

class Application:
    def __init__(self, port):
        self.port = port

    def perform_action(self):
        self.port.execute()

class Port:
    def execute(self):
        print("Executing action.")

class Adapter(Port):
    def execute(self):
        print("Executing action from adapter.")

# Usage
adapter = Adapter()
app = Application(adapter)
app.perform_action()

• Keep the core domain logic independent of frameworks and libraries.
• Define clear interfaces for ports to ensure adaptability.
• Use dependency injection to manage adapters.
• Focus on testing the core logic in isolation.