This project started out as a follow up sample project for our talk at DroidYangon 2019. The app includes handling of reactive friendly use cases in clean mvi way: toggling favourite status, filtering and sorting for example. It also showcases the application of the following important concepts:

• Immutability (No var. Data can't be modified once emitted from the Model)
• Unidirectional data flow (view -> intent -> model -> view )
• Single source of truth (Only one source of data emission: The Model)
• Dependency Inversion (Business rule depends on data sources? NO. Data sources depend on abstraction defined by Business Rule)

Model here means a combination of Interactor and Repository

It also leverages epoxy lib to construct view sections. With kotlin declarative syntax, it's an awesome experience to build complex ui with only a single recyclre view.

Not necessary a requirement but using mosby lib helps you hit the ground running a lot faster. The lib provides retaining presenter which survives device orientation changes and some MVI related goodies. With a bit more work, we can definitely use google's viewmodel in place of mosby presenter though. Just a matter of personal preferences. Don't forget to change orientation while testing and see the result.

The selling point of MVI is state management. This little sample wouldn't worth a penny if it falls short of it. To make the game a bit more competitive, offline support is added to the mix, showing progressBar is split into two modes: Circle progress[when data is empty] and horizontal progress[when data is not empty]. Showing error also has two modes. Just turn off network data to see the error. Well, have fun architecting!