Build for Scale: The facade Pattern

Introduction

This series of build for scale: Is About the advanced way to use React native app.

I will talk about methods, best practices, how-to use guides, and advanced approaches on how to use the most used tools, and packages. Taking into account how to structure it in your app, how to architect the solution, and advanced approaches for a performant, secure, and scalable app.

This series is perfect for React Native developers of all levels who want to take their skills to the next level and build apps that stand the test of time. Whether you’re a seasoned professional or just starting, you’ll find invaluable knowledge and practical guidance to transform your React Native development journey I explained in the previous article how to optimise

When it comes to development, simplifying complex systems is a fundamental principle for enhancing code readability, maintainability, and scalability. This problem has been and still is in coding.? We want to engineer our codebase, so that the app scales with more users, and with more developers coming into the app, it is easy for collaboration. When the packages become outdated, we can easily upgrade them without affecting the whole app. For that as engineers, we use Best practices and Patterns.

In this article, I will talk about the Facade principle.

What is the Facade principle?

The Facade pattern is a design pattern commonly used in software development to simplify interactions with complex systems. In React, it aims to provide a single, well-defined interface for interacting with various components, APIs, or other functionalities within your application

Benefits of using Facade pattern in?React:

• Improved code readability and maintainability: Encapsulates complex logic within a single class or object, making your code easier to understand and manage.
• Reduced coupling: Decouples your components from the underlying implementation details, promoting loose coupling and facilitating changes to the underlying logic without impacting the components using it.
• Easier testing: Isolates the core logic for better testing and debugging

When to use The facade?Pattern

1. Complex Systems: When dealing with intricate systems composed of numerous components or APIs, the Facade pattern helps simplify interactions by providing a single, unified interface. This is especially useful in React Native apps where multiple libraries, APIs, and native modules may need to be integrated.
2. Cross-Platform Development: In React Native, which enables cross-platform development for iOS and Android, the Facade pattern can abstract platform-specific differences. By encapsulating platform-specific logic behind a facade, developers can write cleaner, more maintainable code that is easier to port between platforms.
3. API Abstraction: When working with external APIs or services, a facade can hide the complexity of the underlying API calls, authentication mechanisms, and data transformations. This simplifies the usage of APIs and shields the rest of the application from changes in the API implementation.
4. Legacy Code Integration: When integrating legacy code or third-party libraries into a React Native app, the Facade pattern can serve as a bridge between the existing codebase and the modern React Native architecture. It allows developers to gradually refactor or replace legacy components without disrupting the functionality of the app.
5. Testing and Mocking: Facades can also facilitate testing by providing a clear boundary between the code being tested and its dependencies. Mocking or stubbing the facade’s methods allows for easier unit testing of components that rely on external resources

Use Case of using the Facade?Pattern

Scenario: Imagine an e-commerce application with a “Product Details” page displaying product information, including reviews and ratings. The page might involve:

• Fetching product details from an API.
• Fetching product reviews from a separate API endpoint.
• Calculating average ratings from the reviews

This approach has several drawbacks:

• Repetitive code: The data fetching logic is duplicated for product details and reviews.
• Scattered logic: Calculating the average rating requires accessing reviews from a separate state variable.
• Tight coupling: Changes to the API or data structure would require modifying multiple parts of the component.

How to Fix the code using the Facade?pattern:

Define the Facade: Create a class or object that acts as the single entry point for interacting with the underlying system.?

for our use case: it is the API call, and the average calculation

Encapsulate complexity: Inside the Facade, define methods that handle the interaction with the underlying functionalities or systems. This includes:

• Making API calls (if applicable)
• Data manipulation and processing
• Business logic implementation

for our use case: we can encapsulate the API call and average calculation inside a class, and use that class in component

Provide a simple interface: Expose public methods in the Facade through its interface, allowing other components to interact with it easily. These methods should:

• Have clear and concise names reflecting their purpose.
• Accept and return data in a well-defined format.
• Hide any internal implementation details.

for our use case: the code will follow

Utilize the Facade: In other components or parts of your application, instead of directly interacting with the complex system, use the methods provided by the Facade.

For our case, we will have the following:

We can use it as the following:

Conclusion

Remember the following:

• The Facade pattern isn’t suitable for every situation. Consider its benefits and potential complexity before applying it.
• The provided example serves as a basic illustration. You can further customize the Facade class to handle different types of data fetching, error handling, or other functionalities based on your specific needs

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