Modeling ViewModel State in Android: A Guide to Clean, Scalable Patterns

Poorly designed presentation models can complicate ViewModel classes, leading to bloated, error-prone code. This post explores different approaches to modeling ViewModel state in Android, starting with plain data classes and enums, moving to sealed interfaces, and ultimately proposing a method that combines data classes and sealed interfaces. This hybrid approach aims to offer simplicity, readability, and scalability, while ensuring data consistency across different UI states. The post also includes code examples to illustrate each approach and highlights the pros and cons, recommending unit tests to catch errors.