Unidirectional flow implemented using the latest Swift Generics and Swift Concurrency features
swift-unidirectional-flow
Unidirectional flow implemented using the latest Swift Generics and Swift Concurrency features.
struct SearchState: Equatable {
var repos: [Repo] = []
var isLoading = false
}
enum SearchAction: Equatable {
case search(query: String)
case setResults(repos: [Repo])
}
struct SearchReducer: Reducer {
func reduce(oldState: SearchState, with action: SearchAction) -> SearchState {
var state = oldState
switch action {
case .search:
state.isLoading = true
case let .setResults(repos):
state.repos = repos
state.isLoading = false
}
return state
}
}
struct SearchDependencies {
var search: (String) async throws -> SearchResponse
}
struct SearchMiddleware: Middleware {
func process(
state: SearchState,
with action: SearchAction,
using dependencies: SearchDependencies
) async -> SearchAction? {
switch action {
case let .search(query):
let results = try? await dependencies.search(query)
return .setResults(repos: results?.items ?? [])
default:
return nil
}
}
}
typealias SearchStore = Store<SearchState, SearchAction, SearchDependencies>
struct SearchContainerView: View {
@StateObject private var store = SearchStore(
initialState: .init(),
reducer: SearchReducer(),
dependencies: .production,
middlewares: [SearchMiddleware()]
)
@State private var query = ""
var body: some View {
List(store.state.repos) { repo in
VStack(alignment: .leading) {
Text(repo.name)
.font(.headline)
if let description = repo.description {
Text(description)
}
}
}
.redacted(reason: store.state.isLoading ? .placeholder : [])
.searchable(text: $query)
.task(id: query) {
await store.send(.search(query: query))
}
.navigationTitle("Github Search")
}
}
To learn more about Unidirectional Flow in Swift, take a look at my dedicated post.