Repository vs Dependency Injection Pattern vs UOW(Unit of work)

It acts like an abstract layer between Models and data access technologies. Data access logic is centralized making code maintainable, testable and modular.

Where and Why to Use the Repository Pattern in iOS

It aligns well with modern iOS architecture practices like MVVM (Model-View-ViewModel), Clean Architecture, and VIPER, where separation of concerns and testability are key.

1. Data Abstraction: iOS apps often interact with various data sources like Core Data, UserDefaults, remote APIs, or even mock data during testing. The Repository Pattern abstracts these data sources.
2. Flexibility: You can swap out the data source (e.g., switch from local storage to a remote API) without changing the business logic or UI layer.
3. Testability: Mock repositories can be used during unit testing to simulate data sources.
4. Centralized Logic: Consolidates data handling for specific entities, making the code more modular and easier to maintain.

Example: Data Access Objects (DAOs) vs Repository Pattern

DAOs are commonly used to interact with databases. They tightly couple data access to the underlying database. In contrast, repositories decouple the data access layer, allowing flexibility (e.g., switching from a local database to a remote API).