PRWeatherApp

Overview

PRWeatherApp is a modern iOS weather application built with SwiftUI. It allows users to manage a list of cities, view current weather details, and access historical weather data. The app is designed for maintainability, testability, and a smooth user experience.

Screenshots

Architecture

• MVVM Pattern: The app uses Model-View-ViewModel for clear separation of concerns.
  • Models: Represent weather data, cities, and persistence entities.
  • ViewModels: Handle business logic, state management, and data fetching.
  • Views: SwiftUI views for UI presentation and user interaction.
• Networking: Abstracted via protocols (WeatherServiceProtocol, WeatherAPIClientProtocol) for easy mocking and testing.
• Persistence: Uses Core Data via a PersistenceManager abstraction.
• Error Handling: Centralized with ErrorUtils for extracting error messages.
• Testing: Includes unit tests for view models and services, with mocks for dependencies.

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File/Folder Structure

PRWeatherApp/
├── Features/
│   ├── MainView/
│   ├── DetailsView/
│   └── HistoricalDataView/
├── Helpers/
├── Network/
├── Persistence/
├── Shared/
├── Utilities/
├── Resources/
├── Configs/
├── Preview Content/
├── PRWeatherAppApp.swift
├── ...
PRWeatherAppTests/
PRWeatherAppUITests/

• Features/: Contains feature modules (Main, Details, Historical Data) with their Views, ViewModels, and Models.
• Helpers/: Utility functions (e.g., date formatting, temperature conversion).
• Network/: Networking layer (API client, service, bridging header).
• Persistence/: Core Data manager and model files.
• Shared/: Reusable UI components (buttons, backgrounds, fonts).
• Utilities/: Error handling, parsing utilities.
• Resources/: Assets, fonts, colors.
• Configs/: App configuration files (Info.plist).
• Preview Content/: SwiftUI preview assets.
• Tests/: Unit and UI tests for app logic and user flows.

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Component Flow Diagram

+-------------------+
|      Views        |
|  (SwiftUI UI)     |
+-------------------+
          |
          v
+-------------------+
|    ViewModels     |
| (State, Logic)    |
+-------------------+
          |
          v
+-------------------+-------------    
|           Services              |   
| (WeatherService, localManager)  |
+-------------------+-------------   
          |
          v
+-------------------+
|   API Client      |
| (WeatherAPIClient)|
+-------------------+
          |
          v
+-------------------+
|   Network Layer   |
+-------------------+

ViewModels <----> PersistenceManager (Core Data)

Error Handling: ErrorUtils (used throughout)
Parsing: Parser (used by Services)

• User interacts with Views (SwiftUI)
• Views bind to ViewModels (MVVM)
• ViewModels fetch data from Services (networking)
• Services use API Clients to get data from the network
• Data is parsed and returned to ViewModels
• ViewModels may store/fetch data via PersistenceManager (Core Data)
• ViewModels update Views with new state

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Design Rationale

• SwiftUI: Enables declarative UI and state-driven design.
• Dependency Injection: Improves testability and flexibility.
• Async/Await: Modern concurrency for networking and persistence.
• State Management: UI states (loading, error, empty, loaded) are handled explicitly for robust UX.

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Testing

• Unit Tests: Located in PRWeatherAppTests/, covering view models and services.
• UI Tests: Located in PRWeatherAppUITests/.
• How to Run Tests:
  • In Xcode, select Product > Test or press Cmd+U.

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Last updated: October 20, 2025