SwiftPokedex

SwiftPokedex is a simple Pokedex app written by Viktor Gidlöf in Swift that implements the PokeAPI. For full documentation and implementation of PokeAPI have a look at the their documentation.

This sample app demonstrates:

• RIB architecture 🏛
• Network capabilities using Combine ⚡️
• Data driven table and collection views 💾
• Async image download and caching 🏞
• Swift dot syntax ✏️
• Custom navigation bar 🧭
• Custom fonts 📖
• Infinite scrolling 📜

It downloads an array of Pokemon and displays them in a grid. The most dominant color of the Pokemon sprite is detected and shown in the UI. It also shows a list of the most common items.

Architecture 🏛

SwiftPokedex is written in my own interpretation of the RIB archtitecure created by Uber. The name RIBs is short for Router, Interactor and Builder, which are core components of the architecture.

Builder 🛠

The builder build the views with all of their dependencies.

final class PokedexViewBuilder {
    
    static func build() -> NavigationController {
        let router = PokedexRouter()
        let interactor = PokedexInteractor(router: router)
        let viewController = PokedexViewController(interactor: interactor)
        let navigationController = NavigationController(rootViewController: viewController)
        
        router.navigationController = navigationController
        return navigationController
    }
}

Interactor 👇🏻

The interactor is the link between the user input and the view and includes all the interations the user can make. It also contains a router object. So when the user interacts with the view we call the interactor to make the appropriate interaction.

override func collectionView(_ collectionView: UICollectionView, didSelectItemAt indexPath: IndexPath) {
    collectionView.deselectItem(at: indexPath, animated: true)

    interactor.selectPokemon(at: indexPath, in: collectionView)
}

Router 🕹

The router is in charge of navigation. And since routers are decoupled from view controllers we can easily navigate to anywhere in the app.

func routeToDetailView(pokemon: PokemonDetails, color: UIColor) {
    let detailView = DetailViewBuilder.build(from: pokemon, withColor: color)
    navigationController?.pushViewController(detailView, animated: true)
}

Networking ⚡️

SwiftPokedex uses Combine for all the API calls to the PokeAPI. This small structure is all that's needed to make any type of request to the API. The PokemonAPI and ItemAPI is then build around this network agent. It supports requesting pokemons and items at the moment.

struct NetworkAgent {
    func execute<T: Decodable>(_ request: URLRequest, logJSON: Bool = false) -> AnyPublisher<T, Error> {
        URLSession.shared.dataTaskPublisher(for: request)
            .tryMap {
                if logJSON { print($0.data.prettyJSON ?? "no json") }
                return $0.data
            }
            .decode(type: T.self, decoder: JSONDecoder())
            .eraseToAnyPublisher()
    }
}

Data driven tables and collection views 💾

The table views and collection views are data driven and they setup their own UI based on the data they are given. So setting up a collection view data source is done like this:

let items = pokemon.map { CollectionCellConfiguration<PokedexCell, PokemonDetails>(data: $0) }
let section = UICollectionView.Section(items: items)
let collectionData = UICollectionView.DataSource(sections: [section])

By configuring the cells using CollectionCellConfiguration we tell the collection view that the data type we want to use is PokemonDetails and the custom cell is PokedexCell. This make setting up cells type safe as well. Then the collection view automatically renders that data with those cells. No need to implement any of the collection delegate or data source methods in the view controller. That is done with the CollectionCellConfigurator protocol and a subclass of UICollectionViewController.

Todo 📝

The PokeAPI is very extensive and it contains a lot of things. Here are some things that I plan to implement further down the line:

• Request pokemon
• Search pokemon
• Pokedex pagination
• Show pokemon details
• Request items
• Search items
• Show item descriptions
• Implement other parts of the API such as:
  • Moves
  • Abilities
  • Berries

Requirements ❗️

• Xcode 12.0+
• iOS 14.1+
• Swift 5+