Multi Model messaging does not appear to be working correctly...

[nghtstr]

So, I have a main model, and two sub models. The main model is basically doing nothing more than displaying the two other models (status and currentTest) in the format that I want. So far, that is working great. Now, I have in the main model, I have the current state of the application, which includes information that the rest of the models will require. I got around this problem by passing that state as a part of a tea.Cmd message, which the two other models get. Now, the currentTest model has its own state listeners, and this is where things are breaking down. For whatever reason, even though I know that the secondary sate is being sent as a message (gotta love logging), my currentTest model isn't picking it up. Here is a code snippet:

func (ct currentTestModel) sendCBState() tea.Msg {
	log.Println("Here 3")
	log.Printf("cbState: %T\n", ct.cbState)
	return ct.cbState
}

func (ct currentTestModel) sendGatheringState() tea.Msg {
	return ct.cbState.currentGatheringState
}

func (ct currentTestModel) Init() tea.Cmd {
	return ct.createDatabaseConnection
}

func (ct currentTestModel) Update(msg tea.Msg) (tea.Model, tea.Cmd) {
	switch msg := msg.(type) {
	case tea.KeyMsg:
		switch {
		case key.Matches(msg, DefaultKeyMap.Quit):
			return ct, tea.Quit
		}
	case tea.WindowSizeMsg:
		return ct, nil
	case state:
		sendState := false
		ct.currentState, sendState = ct.currentState.update(msg)
		ct.cbState.currentIndex = -1

		if sendState {
			log.Println("Here 2")
			return ct, tea.Batch(ct.sendState, ct.sendCBState)
		}

		return ct, ct.sendCBState
	case costbasisState:
		log.Println("Here")
		sendState := false
		ct.cbState, sendState = ct.cbState.update(msg)

		if sendState {
			return ct, tea.Batch(ct.sendCBState, ct.sendGatheringState)
		}
    ...
}

Also, here is the contents of my log file:

debug 2022/10/18 20:25:56 Here 2
debug 2022/10/18 20:25:56 Should not have gotten here (Type: main.mainModel)
debug 2022/10/18 20:25:56 Should not have gotten here (Type: main.mainModel)
debug 2022/10/18 20:25:56 Here 3
debug 2022/10/18 20:25:56 cbState: main.costbasisState
debug 2022/10/18 20:25:56 Here 2
debug 2022/10/18 20:25:56 Should not have gotten here (Type: main.mainModel)
debug 2022/10/18 20:25:56 Here 3
debug 2022/10/18 20:25:56 cbState: main.costbasisState
debug 2022/10/18 20:25:56 Should not have gotten here (Type: main.mainModel)
debug 2022/10/18 20:25:56 Here 3
debug 2022/10/18 20:25:56 cbState: main.costbasisState
debug 2022/10/18 20:25:56 Should not have gotten here (Type: main.mainModel)
debug 2022/10/18 20:25:56 Here 3
debug 2022/10/18 20:25:56 cbState: main.costbasisState
debug 2022/10/18 20:25:56 Should not have gotten here (Type: main.mainModel)

[erwin]

I was also struggling to figure out how to implement an application that held multiple models, until I found this example in the bubblezone codebase:

https://github.com/lrstanley/bubblezone/blob/master/examples/full-lipgloss/main.go

Perhaps I've missed something. It seems more simple to me than what you describe manually passing around state...

Basically inside of the Update() method for your main model, do something like:

	return m.propagate(msg), nil

Where propagate forwards event messages to the nested models.

Note that the bubblezone example is very simple though, it's not actually tracking the cmd returned from your sub-models, so if your sub-models generate events, you have to make sure to save them and append them with something like...

func (m MainModel) Update(msg tea.Msg) (tea.Model, tea.Cmd) {
  util.LogF("%s", msg)
  var (
    cmd   tea.Cmd
    cmds  []tea.Cmd
  )
  // do MainModel's event handling...
  return m.propagate(msg, cmds)
}

func (m *MainModel) propagate(msg tea.Msg, cmds []tea.Cmd) (tea.Model, tea.Cmd) {
  var (
    cmd   tea.Cmd
  )
  switch msg := msg.(type) {
  default:
    m.status, cmd    = m.status.Update(msg)
    cmds            = append(cmds, cmd)
    m.currentTest, cmd = m.currentTest.Update(msg)
    cmds            = append(cmds, cmd)
  }
  return m, tea.Batch(cmds...)
}