queiroz / themoviedb

Popular Movies

Popular Movies (The Movie Database)

Pre-conditions

Grab an API key from https://www.themoviedb.org/settings/api. Then add the key into the gradle global properties gradle.properties at ~/.gradle/gradle.properties:

vim ~/.gradle/gradle.properties

then paste the key:

# The Movie DB API Key
theMovieDbApiKey="API_KEY"

Please note that gradle version 4.0.0-alpha09 is required as well as gradle-6.1-rc-1-all as Android Studio Preview 4 was used to write the app, because why not!

App stack

Kotlin

• Kotlin gradle DSL
• Coroutines
• Coroutines-android

Jetpack

• Test
• Android KTX
• ViewModel
• Navigation
• Paging
• LiveData
• Fragment
• ViewPager2
• Data Binding
• Animation & transitions

Other

• Dagger2/dagger-android
• Android-extensions
• Picasso
• Retrofit
• Retrofit Gson
• OkHttpInterceptor
• Timber
• PlainPie

Extra Implementation Details

PagedList/DataSource The data source has the capability of retrying from the point it failed, thanks to the use of the executor. If 20 items are being displayed and Wifi is turned off or lack of network connectivity or server timeout, the executor will try to fetch data from that point on so that the entire list does not have to be reloaded.

RecyclerView Adapter/ListAdapter Use of DiffUtil for background list diff computation. Custom views. Use of recycler view and view pager 2 without Fragments

Shared Element Transition with Jetpack Navigation Cover is being shared between List item and MovieDetailFragment.

Jetpack Navigation NavHostFragment with the latest recommendation of FragmentContainerView.

Also in order to get the NavController we have to find the Fragment first then look for NavController as there are issues getting the NavController directly with findNavController(R.id.container) because of Fragment lifecycle issues.

private val navController: NavController by lazy {
    (supportFragmentManager.findFragmentById(R.id.container) as NavHostFragment).navController
}

Unit Test

Testing view model interactions with LiveData and PagedList.

UI Test

Uses Fragment Scenario and espresso to test recyclerview item navigation with jetpack Navigation library.

Implemented Fragment Factory with Dagger 2 and Androidx Navigation library so Fragments can take constructor arguments from daggers graph.

Now Fragment constructor arguments can easily be mocked or switched with fakes for testing.