I'm very familiar with MVVM architectural pattern in android. To take it much further, I'm doing my next project by following clean code principles (SOLID). I have separated the entire app in three modules. 1) App (presentation + framework) 2) Data 3) Domain. My doubt is that whether I can keep library dependencies (i.e. Firebase) in Data module or not. Right now, I'm using interface to access app related stuffs like shared preferences, location fetchers, retrofit, etc.
I need to expect values like AuthResult from Data module. For that I need to add Firebase dependencies in the data module's Gradle file. I think that will violate the Higher level module should not depend on lower lever module rule.
Can anyone clarify this for me?
After going through several articles on MVVM + Clean Code, I came to a conclusion that I cannot be using any dependencies related to android framework inside either domain or data module. Otherwise it will be violating the Dependency Inversion principle of SOLID.
Dependency Inversion principle
Higher level module should not be dependent on Lower level modules, and both should be dependent on abstraction.
In English -> You cannot directly access framework related components like database, gps, retrofit, etcetera from data or domain layers. They should not care about those stuffs. They should be totally independent of android related components. We can use interface to satisfy the rule of abstraction.
Therefore, my data module and domain module contains only language dependencies. Whatever android-framework-related data I want, I acquire it by implementing interfaces.