PokemonApp (SwiftUI)

A simple SwiftUI Pokédex that fetches data from PokeAPI, supports infinite scrolling, pull-to-refresh, detail screens, offline cache for list and details, and favorites persisted with UserDefaults.

Features

• Pokémon list with official artwork
• Infinite scroll with prefetching near the end
• Pull to refresh
• Detail screen with base experience, height, weight and artwork
• Favorites: mark/unmark, view favorites tab, clear all with confirmation
• Offline support: cached list and details, graceful errors when offline
• Error handling with retry

Tech stack

• SwiftUI for UI
• Combine for async networking pipelines
• URLSession for HTTP requests to PokeAPI
• Kingfisher for remote image loading and caching
• Network framework (NWPathMonitor) for connectivity awareness
• UserDefaults as a simple cache/persistence layer
• Architecture: MVVM (views + PokemonViewModel + models)

Requirements

• Xcode 15+
• iOS 16+
• Swift Package Manager (built into Xcode)

Project structure

• PokemonAppApp.swift – App entry point, injects PokemonViewModel
• ContentView.swift – Segmented tabs: All / Favorites
• PokemonListView.swift – List, infinite scroll, pull-to-refresh, empty states, error alerts; uses Kingfisher
• PokemonDetailView.swift – Details (opened from the list)
• PokemonViewModel.swift – Pagination, networking, caching, favorites, error handling
• PokemonModels.swift – Codable models, cache helper, error definitions
• Assets.xcassets – Assets

Data source

• PokeAPI: https://pokeapi.co/
  • List: GET /api/v2/pokemon?limit={limit}&offset={offset}
  • Details: GET /api/v2/pokemon/{id}
  • Artwork: GitHub sprites repo (official-artwork)

Setup and run

1. Open PokemonApp.xcodeproj in Xcode.
2. Ensure the Kingfisher package is added via SPM if Xcode prompts to resolve packages:
   • File → Add Packages… → Search for https://github.com/onevcat/Kingfisher
   • Add to the project target.
3. Select an iOS simulator (iOS 16+).
4. Build and run (Cmd+R).

Notes on caching and offline

• List cache: stored as JSON in UserDefaults and used when offline.
• Details cache: per Pokémon detail JSON cached on first successful load.
• Favorites: stored as a Set<String> of Pokémon IDs in UserDefaults with ability to clear all.