Babylon Posts - A Showcase Application

Architecture

The app uses a feature module approach. In this case the feature modules are

• postlist module
• postdetails module

In a real life scenario this would probably have been one feature module but for demonstration purposes they are split into two now.

All feature modules rely on the

• core module

The core module contains all the dependencies the feature modules need and also sets them up. It also shares the app's resources like colors, dimensions, strings, styles, themes, and typography.

The

• app module

then simply combines the needed feature modules by implementing them in it's own gradle file and coordinating their usage. The app follows the single activity pattern --> each feature module contains fragments which are displayed within this one activity.

Navigation is achieved with Jetpack's Navigation Graph. The nav_graph.xml is also situated within the app module.

Apart from that the application uses a MVVM pattern with the ViewModel from Jetpack's Architecture Components and a repository pattern to be able to provide the data from different sources. In this case the data sources are network and memory cache. Once the data is loaded it is retrieved from memory unless the forceRefresh flag is set.

Technology

• Kotlin
• Kotlin Coroutines
• Retrofit
• Glide
• Koin
• JUnit 4

Tests

• Due to it's simplicity the project is only unit tested - You can run the tests by typing

./gradlew testAll 

This task combines the unit tests from all modules

Design

The app's theme inherits from the MaterialComponents theme to be able to use the Material Theming, e.g. components like MaterialCardView.

The parallax effect in the details screen is achieved with a CoordinatorLayout with a CollapsingToolbarLayout. The hero animation is done with a Shared Element Transition.