Clean MVP

Requirements:

Functional:

• Fetching and parsing data from API.
• Listing Data.
• Searching.
• Pagination.
• Navigation to Details view.

Non-Functional:

• Performance:

  • Caching images.

• Scalability:

  • Modularity.

• Reliability:

  • Unit tests.

Low-Level Design

Design Decisions

• UI:

  • UIKit
  • MVP Architecture

• Principals and Patterns:

  • SOLID conformance:
    • Features are separated into modules.
    • UseCases for business logic.
  • Utilizing IoC and DI.
  • Coordinator pattern for navigation.

• Dependency Manager:

  • Swift Package Manager (SPM)

• Dependencies:

  • Kingfisher: Downloading and caching images from the web.

Notes:

• Design Patterns:
  • Bridge Design Pattern (BaseVC and BasePresenter) is used to avoid code duplication.
  • Adapter Design Pattern (HTTPClient and WatchlistDataStore) is used to easily swap HTTP clients or Data Persistence if needed (ex. Alamofire instead of URLSession).
  • Composite Reuse Principle (CRP) (DataSources and Delegates) is used to compose the ViewControllers.
  • An Automatic DI Container (Resolver or Swinject) could be used if the project got bigger.
  • Repository Pattern could be used if local data storage is needed in the future.
• iOS APIs:
  • DispatchGroup (SimilarMoviesUseCase) is used to handle multiple async network calls.
  • Race Conditions are avoided in SimilarMoviesUseCase using a serial DispatchQueue.
  • A Set is used over an Array in WatchlistDataStore to achieve O(1) search time complexity.
• To achieve better UX:
  • ActivityIndicator for each network called is used.
  • Debouncer is used to avoid unneeded search results and UI refreshes.
  • DarkMode and Landscape modes are supported.
  • Errors are handled to avoid failing silently.
  • Different placeholders are used for different image types (poster or cast).
• All the presenters are unit tested (15 tests in total).

GitHub

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