Passing params along to child state

[rzolin]

Hey guys, I would appreciate some help here. I have the following code (redacted for simplicity):

public struct ATAppFeature: Reducer {

   public struct State: Equatable {
        public var flow: MainFlow = .appInit
        public var initialization = ATAppInitializationFeature.State(title: "Loading...")
   }
   
    public enum Action: Equatable {
        case showInitialization(ATAppInitializationFeature.Action)
   }
   
   Scope(state: \.initialization, action: /Action.showInitialization) {
        ATAppInitializationFeature()
   }
}

struct ATAppView: View {

   @Environment(\.accountId) var accountId

    var body: some View {
        WithViewStore(self.store, observe: ViewState.init) { viewStore in
            Group {
                switch (viewStore.flow) {
                case .appInit:
                    ATAppInitialization(
                        store: self.store.scope(
                            state: \.initialization,                 //  <-- want to pass `accountId` here
                            action: ATAppFeature.Action.showInitialization    
                        )
                    )

And when I initialize the ATAppInitialization reducer, I would like to pass a param (accountId). But the state is predefined in the ATAppFeature.State. Creating directly doesn't help. So I wonder how can I inject that value during the scoping of the store, or maybe somewhere else?

[natemann]

How about an action on 'onAppear'

[rzolin]

How do you see it, @natemann? Is the onAppear for the parent or the child view? The parent view doesn't quite hold the reference to the child view. Only the state \.initialization, which I can try to modify.
I was actually was thinking of adding some kind of modifier to the store, something like this:

                    ATAppInitialization(
                        store: self.store.scope(
                            state: \.initialization,                 
                            action: (ATAppFeature.Action.showInitialization)
                                     .appending(path: ...).  // or the next one
                                     .modify(...)
                        )
                    )

I've seen their use once in the episodes. But I don't know how or when to use them. And couldn't find any good examples or docs

[rzolin]

I think I found how to solve this:

                     ATAppInitialization(
                        store: self.store.scope(
                            state: { store in
                                var state = store.initialization
                                state.accountId = sceneSession?.accountId
                                return state
                            },
                            action: ATAppFeature.Action.showInitialization
                        )
                    )