hi all! I am making some home-made application whe...

# android-architecture

[Joost Klitsie]

hi all! I am making some home-made application where I use a data flow like:
Repository <-> UseCase <-> ViewModel <-> View
So basically UseCase with MVVM
I can find some basic introductions about the usecase pattern, but does anyone have some in-depth article/repo example?

I am looking for information about things like this:
• Things like observing data (should I first fetch data and after that observe on it, within the useCase)
• when to fire a use case and for specific things (like would you fire a usecase to validate input while typing, or only while submitting?)
• Should I observe fields from a usecase, or only the output from the execution?
• What are the rules where to put specific logic, in the view model or usecase (or both)?

[Javier]

UseCases generally should be used in ViewModels (or presenters), and views observe

UseCases maybe is not returning a Flow (or whatever API you are using), for example, if your app only gets data from network, you don't need to pass a Flow from datasources -> repositories -> use cases, you only need a suspend fun and the ViewModel can emit the state with Flow or LiveData