Understanding Tight Coupling

Oct 13, 2025 by leolavanderia.com.br 127 views

Introduction

In software development, tight coupling between components can lead to inflexibility, making it challenging to modify or replace individual components without affecting the entire system. In the context of the Interp-Service project, we have identified two instances of tight coupling: between the sockets handlers and the GCPService, and between the APIRouter and the GCPService. In this article, we will explore how to extend the service interface pattern to decouple the APIRouter from the GCPService.

Understanding Tight Coupling

Tight coupling occurs when two or more components are highly dependent on each other, making it difficult to modify or replace one component without affecting the others. In the case of the Interp-Service project, the sockets handlers and the GCPService are tightly coupled because the sockets handlers rely on the GCPService to process audio data. Similarly, the APIRouter is tightly coupled with the GCPService because it directly calls methods on the GCPService instance to retrieve supported languages.

Creating an Interface for the APIRouter

To decouple the APIRouter from the GCPService, we need to create an interface that defines the methods that the APIRouter will use to interact with the service. Let's call this interface IRestService. The IRestService interface will define the methods that the APIRouter will use to retrieve supported languages.

from typing import List

class IRestService:
    def get_supported_languages(self) -> List[str]:
        pass

Implementing the IRestService Interface

Now that we have defined the IRestService interface, we need to implement it in the GCPService class. The GCPService class will provide an implementation of the get_supported_languages method.

from google.cloud import language_v1
from typing import List

class GCPService:
    def __init__(self):
        self.client = language_v1.LanguageServiceClient()

    def get_supported_languages(self) -> List[str]:
        languages = self.client.list_languages()
        return [language.language_code for language in languages]

Refactoring the APIRouter

With the IRestService interface in place, we can now refactor the APIRouter to interact with the interface instead of the GCPService instance. We will create a dependency on the IRestService interface and inject an instance of the GCPService class into the APIRouter constructor.

from fastapi import APIRouter
from typing import List

router = APIRouter()

@router.get("/getSupportedLanguages")
async def get_supported_languages(rest_service: IRestService):
    return rest_service.get_supported_languages()

Benefits of Decoupling

By decoupling the APIRouter from the GCPService, we have achieved several benefits:

Increased flexibility: We can now easily switch to a different service implementation without affecting the APIRouter.
Improved testability: We can test the APIRouter independently of the GCPService implementation.
Reduced coupling: We have reduced the tight coupling between the APIRouter and the GCPService, making it easier to modify or replace individual components.

Conclusion

In this article, we have explored how to extend the service interface pattern to decouple the APIRouter from the GCPService. By creating an interface for the APIRouter and implementing it in the GCPService class, we have achieved several benefits, including increased flexibility, improved testability, and reduced coupling. This approach will make it easier to modify or replace individual components in the Interp-Service project without affecting the entire system.

Future Work

In the future, we can further decouple the sockets handlers from the GCPService by creating an interface for the sockets handlers and implementing it in the GCPService class. This will provide even more flexibility and reduce coupling between the sockets handlers and the GCPService.

Example Use Cases

Here are some example use cases for the decoupled APIRouter:

Switching to a different service implementation: We can easily switch to a different service implementation by creating a new class that implements the IRestService interface and injecting it into the APIRouter constructor.
Testing the APIRouter independently: We can test the APIRouter independently of the GCPService implementation by creating a mock implementation of the IRestService interface.
Reducing coupling between components: We have reduced the tight coupling between the APIRouter and the GCPService, making it easier to modify or replace individual components.
Q&A: Extending the Service Interface Pattern to Decouple Service from APIRouter ================================================================================

Introduction

In our previous article, we explored how to extend the service interface pattern to decouple the APIRouter from the GCPService. We created an interface for the APIRouter and implemented it in the GCPService class, achieving several benefits, including increased flexibility, improved testability, and reduced coupling. In this article, we will answer some frequently asked questions about extending the service interface pattern to decouple service from APIRouter.

Q: Why do I need to decouple the APIRouter from the GCPService?

A: Decoupling the APIRouter from the GCPService provides several benefits, including increased flexibility, improved testability, and reduced coupling. By decoupling the APIRouter from the GCPService, you can easily switch to a different service implementation without affecting the APIRouter.

Q: How do I create an interface for the APIRouter?

A: To create an interface for the APIRouter, you need to define the methods that the APIRouter will use to interact with the service. Let's call this interface IRestService. The IRestService interface will define the methods that the APIRouter will use to retrieve supported languages.

from typing import List

class IRestService:
    def get_supported_languages(self) -> List[str]:
        pass

Q: How do I implement the IRestService interface?

A: To implement the IRestService interface, you need to create a class that implements the methods defined in the interface. In this case, we will implement the get_supported_languages method in the GCPService class.

from google.cloud import language_v1
from typing import List

class GCPService:
    def __init__(self):
        self.client = language_v1.LanguageServiceClient()

    def get_supported_languages(self) -> List[str]:
        languages = self.client.list_languages()
        return [language.language_code for language in languages]

Q: How do I refactor the APIRouter to interact with the interface instead of the GCPService instance?

A: To refactor the APIRouter to interact with the interface instead of the GCPService instance, you need to create a dependency on the IRestService interface and inject an instance of the GCPService class into the APIRouter constructor.

from fastapi import APIRouter
from typing import List

router = APIRouter()

@router.get("/getSupportedLanguages")
async def get_supported_languages(rest_service: IRestService):
    return rest_service.get_supported_languages()

Q: What are the benefits of decoupling the APIRouter from the GCPService?

A: The benefits of decoupling the APIRouter from the GCPService include:

Increased flexibility: You can easily switch to a different service implementation without affecting the APIRouter.
Improved testability: You can test the APIRouter independently of the GCPService implementation.
Reduced coupling: You have reduced the tight coupling between the APIRouter and the GCPService, making it easier to modify or replace individual components.

Q: How do I switch to a different service implementation?

A: To switch to a different service implementation, you need to create a new class that implements the IRestService interface and inject it into the APIRouter constructor.

Q: How do I test the APIRouter independently?

A: To test the APIRouter independently, you need to create a mock implementation of the IRestService interface and inject it into the APIRouter constructor.

Conclusion

In this article, we have answered some frequently asked questions about extending the service interface pattern to decouple service from APIRouter. By decoupling the APIRouter from the GCPService, you can achieve several benefits, including increased flexibility, improved testability, and reduced coupling. We hope this article has provided you with a better understanding of how to extend the service interface pattern to decouple service from APIRouter.