Android Error Handling & Type-Safe Navigation — Architecture Patterns

Android Error Handling & Navigation Arguments — Clean Architecture Patterns Error handling and type-safe navigation are critical for building robust Android apps. This article covers proven patterns using Result sealed classes, AppException hierarchies, and modern Compose navigation with type-safe arguments. Part 1: Error Handling Architecture Result Sealed Class Pattern The Result sealed class pattern provides type-safe error handling across the entire data layer: sealed class Result < out T > { data class Success < T >( val data : T ) : Result < T >() data class Error ( val exception : AppException ) : Result < Nothing >() data class Loading ( val progress : Int = 0 ) : Result < Nothing >() fun < R > map ( transform : ( T ) -> R ): Result < R > = when ( this ) { is Success -> Success ( transform ( data )) is Error -> Error ( exception ) is Loading -> Loading ( progress ) } fun getOrNull (): T ? = ( this as ? Success ) ?. data } AppException Hierarchy Define a comprehensive exception