android-architecture

name

android-architecture

description

Standards for Clean Architecture, Modularization, and Unidirectional Data Flow. Use when anyone sets up Android project structure, asks where code belongs in Clean Architecture layers, discusses modularization (feature/core modules), or questions UDF (events up, state down). (triggers: build.gradle.kts, settings.gradle.kts, clean-architecture, module, layers, domain, UDF, unidirectional, feature module, core module, presentation layer, data layer)

Android Architecture Standards

Priority: P0 (CRITICAL)

Implementation Guidelines

Layering (Clean Architecture)

• Domain: Pure Kotlin (No Android deps). Contains UseCases/Models.
• Data: Repository impl, DataSources (API/DB). Maps DTO -> Domain.
• UI: ViewModel + Composable. Maps Domain -> UiState.

Modularization

• Feature Modules: :feature:home, :feature:profile.
• Core Modules: :core:ui (Design System), :core:network, :core:database.
• App Module: DI Root and Navigation Guard.

Unidirectional Data Flow (UDF)

• Events: UI -> ViewModel (Events).
• State: ViewModel -> UI (StateFlow).

Jetpack Compose

• Hosting: Are you using setContent in Activity? (No XML Layouts)
• State: Is state hoisted to ViewModel using collectAsStateWithLifecycle?
• Unidirectional: Are events passed UP and state passed DOWN?
• Recomposition: Are Composables stable? (Check for unstable types in parameters)
• Navigation: Is Compose Navigation using Type-Safe destinations?

Anti-Patterns

• No Logic in Activity: Host Navigation only.
• No Repo in UI: Access data exclusively via ViewModel.
• No Context in Domain: Keep Logic Pure.

References

• Structure & Examples
• Jetpack Compose Best Practices