Sample Android Application written in Kotlin to show a list of movies by using the TMDb API The MVVM pattern is used to encapsulate App specific domain logic into ViewModels that can be unit tested in isolation. The use of [Android architecture ViewModel](The use https://developer.android.com/topic/libraries/architecture/viewmodel) allows ui state preserving on orientation change. The internals of the ViewModel are based on explicit ui states that are inspired by the talk Managing State with RxJava by Jake Wharton. The ViewModel is backed by a repository which hides the underlying API service and allows later extension by a database backed cache. The communication between Activity and (Dialog-)Fragment is done using a shared ViewModel described in the Android developers documentation section Share data between fragments
The App uses the TMDb API which requires a registered API key for most of the API calls. To build the app the API key needs to be specified as a gradle property with the key "TheMovieDatabaseApiKey" that is accessible by the gradle build system. One possibility is to add it to the gradle.properties file in the user's .gradle folder [USER_HOME]/.gradle/gradle.properties in the following way
TheMovieDatabaseApiKey="{API_KEY}"
- Retrofit 2 HTTP client to query the API and map requests in a declarative way
- Moshi JSON library to parse custom Date attributes
- RxJava 2 reactive extensions for the JVM to handle asynchronous events in a reactive/stream based way
- Koin lightweight Kotlin dependency injection framework that allows simple ViewHolder injection and without code generation
- Groupie RecyclerView layout library that implements delegation pattern to easily add new item types
- Fresco Image loading library for loading movie images
##Improvements (potential next steps)
- Allow API key to be specified as environment variable
- Create intermediate domain model of MovieListResult to be passed to MovieItem that handles pre formatting
- Add option for changing until date filter failure state
- Add an empty result state