SwiftUIRedux

Comprehensive Redux library for SwiftUI.

• Keep State consistent across Stores by type safe pub/sub pattern with Reducers of RootStore.
• Waterfall Action propagation flow from root to State subtree.

Unidirectional Data Flow

• RootStore/Dispatcher: Propagates domained actions

• Reducer: Subscribes to RootStore and reduces Action to generate new state

• Action: Action driven - more loosely coupled pattern than Delegation pattern

• State:

  • Reduces Action and outputs new State
  • Waterfall reduce flow: propagates Action to children nodes via State tree

Declarative/Stateful/Immutable/Predictable

• Efficient tree diff algorithm, no more imperative manual update code.

Usage Example

FeedListView

struct FeedListView: View {
  @ObservedObject var state = FeedListState()
  
  var body: some View {
    List {
      ForEach(state.feeds, id: \.diffId) { feed in
        FeedCell(feed: feed)
      }
    }
  }
}

FeedListState

public class FeedListState: ReduxReducer, ObservableObject {  
  @Published var feeds: [Feed] = []
  
  public override func reduce(action: ReduxActionProtocol) {
    // Propagates `action` to the substate tree.
    // Setting `self.feeds` with new feeds triggers list UI reloading 
    // and SwiftUI will diff efficiently based on list identifier.
    feeds = feeds.map { $0.reduce(action: action) }
}

Dispatch FeedLikeAction

dispatch(action: FeedLikeAction(feed: feed))

Reduce FeedLikeAction

public struct Feed {
  public var diffId = UUID()
  public let feedId: Int
  public let title: String
  public var isLiked: Bool { didSet { diffId = UUID() } }     
}

extension Feed: ReduxStateProtocol {
  @discardableResult
  public func reduce(action: ReduxActionProtocol) -> Self {
    // Makes the deep copy of self.
    var feedCopy = self    
    switch action {
    case let action as FeedLikeAction:
      // Reduces the `FeedLikeAction`.
      if feedId == action.feed.feedId {
        feedCopy.isLiked = !action.feed.isLiked
      }
    default: break
    }
    return feedCopy
  }
}