Which types of logic does the NiaAppState belongs to?

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Types of logic
Bookmarking an article is an example of business logic because it gives value to your app. To learn more about this, see the data layer page. However, there are different types of logic that are important to define:

• Business logic is the implementation of product requirements for app data. As mentioned already, one example is bookmarking an article in the case study app. Business logic is usually placed in the domain or data layers, but never in the UI layer.

• UI behavior logic or UI logic is how to display state changes on the screen. Examples include obtaining the right text to show on the screen using Android Resources, navigating to a particular screen when the user clicks a button, or displaying a user message on the screen using a toast or a snackbar.

The UI logic, particularly when it involves UI types like Context, should live in the UI, not in the ViewModel. If the UI grows in complexity and you want to delegate the UI logic to another class to favor testability and separation of concerns, you can create a simple class as a state holder. Simple classes created in the UI can take Android SDK dependencies because they follow the lifecycle of the UI; ViewModel objects have a longer lifespan.