How to use withDependencies() when appending to NavigationStack path

[alexbird]

It seems that the Store needs to be created inside a withDependencies context. Stack navigation seems to have two points where we construct things, but the actual Store creation happens within the TCA library code. Am I missing something?

We construct:

• The State, e.g.

case .goToABCButtonTapped:
        state.path.append(.screenA(ScreenA.State()))
        return .none

• The View, e.g.

    } destination: { store in
      switch store.case {
      case let .screenA(store):
        ScreenAView(store: store)
      }
    }

...but the Store has been constructed between these definitions, and wrapping neither of these in withDependencies seems to override anything.

[mbrandonw]

Hi @alexbird, in TCA you override dependencies with the .dependency reducer operator (or what of the related APIs).

Can you give more details of what dependency you are wanting to override and where?

[alexbird]

My scenario is a feature displaying various live information on a map, so it has dependencies I've created for API access and a stream of user locations. I want to navigate to this feature from a testbed/demo root feature, which can select either real data or canned data for demonstration purposes.
Would you suggest the way to do this embedding the feature in new reducer/s which uses the .dependency operator, and adding Path case/s for these reducers?

[alexbird]

That does the job, thanks.

I also needed (?) to create a minimal View to embed the feature in, a la:

struct CannedTripMapView: View {
    let store: StoreOf<CannedTripMap>
    
    var body: some View {
        TripMapView(store: store.scope(state: \.feature, action: \.feature))
    }
}

It would be handy if I could inject dependencies into this wrapper, but I cannot see how to use other parts of its state within the Scope() operator. Perhaps this is crazy talk?