✨ implement default coroutine dispatcher in repositories

- convert USE CASES to Singleton

Author: juarezRoberto

app/build.gradle

@@ -42,7 +42,7 @@ android {
 dependencies {
  implementation 'androidx.core:core-ktx:1.7.0'
  implementation 'androidx.appcompat:appcompat:1.4.1'
- implementation 'com.google.android.material:material:1.6.0'
+ implementation 'com.google.android.material:material:1.6.1'
  implementation 'androidx.constraintlayout:constraintlayout:2.1.4'
  implementation 'androidx.legacy:legacy-support-v4:1.0.0'
  testImplementation 'junit:junit:4.13.2'

app/src/main/java/com/juarez/upaxdemo/di/AppModule.kt

@@ -4,24 +4,37 @@ import com.google.firebase.firestore.CollectionReference
 import com.google.firebase.storage.StorageReference
 import com.juarez.upaxdemo.map.data.LocationsRepository
 import com.juarez.upaxdemo.map.data.LocationsRepositoryImp
+import com.juarez.upaxdemo.movies.data.MovieLocalDataSource
+import com.juarez.upaxdemo.movies.data.MovieRemoteDataSource
+import com.juarez.upaxdemo.movies.data.MovieRepository
+import com.juarez.upaxdemo.movies.data.MovieRepositoryImpl
 import com.juarez.upaxdemo.photo.data.ImagesRepository
 import com.juarez.upaxdemo.photo.data.ImagesRepositoryImp
 import dagger.Module
 import dagger.Provides
 import dagger.hilt.InstallIn
 import dagger.hilt.components.SingletonComponent
+import kotlinx.coroutines.Dispatchers
 
 @Module
 @InstallIn(SingletonComponent::class)
 object AppModule {
 
  @Provides
  fun provideLocationsRepository(collectionReference: CollectionReference): LocationsRepository {
- return LocationsRepositoryImp(collectionReference)
+ return LocationsRepositoryImp(collectionReference, Dispatchers.IO)
  }
 
  @Provides
  fun provideImagesRepository(storageReference: StorageReference): ImagesRepository {
- return ImagesRepositoryImp(storageReference)
+ return ImagesRepositoryImp(storageReference, Dispatchers.IO)
+ }
+
+ @Provides
+ fun provideMovieRepository(
+ remoteDataSource: MovieRemoteDataSource,
+ localDataSource: MovieLocalDataSource
+ ): MovieRepository {
+ return MovieRepositoryImpl(remoteDataSource, localDataSource, Dispatchers.IO)
  }
 }

app/src/main/java/com/juarez/upaxdemo/map/data/LocationsRepository.kt

@@ -3,9 +3,12 @@ package com.juarez.upaxdemo.map.data
 import com.google.firebase.firestore.CollectionReference
 import com.google.firebase.firestore.ktx.toObjects
 import com.juarez.upaxdemo.utils.Resource
+import kotlinx.coroutines.CoroutineDispatcher
+import kotlinx.coroutines.Dispatchers
 import kotlinx.coroutines.flow.Flow
 import kotlinx.coroutines.flow.flow
 import kotlinx.coroutines.tasks.await
+import kotlinx.coroutines.withContext
 import javax.inject.Inject
 
 interface LocationsRepository {
@@ -15,16 +18,17 @@ interface LocationsRepository {
 
 class LocationsRepositoryImp @Inject constructor(
  private val locationsCollection: CollectionReference,
+ private val defaultDispatcher: CoroutineDispatcher = Dispatchers.IO
 ) : LocationsRepository {
 
  override suspend fun saveLocation(location: Location) {
- locationsCollection.add(location).await()
+ withContext(defaultDispatcher) { locationsCollection.add(location).await() }
  }
 
  override fun getLocations(): Flow<Resource<List<Location>>> = flow {
  emit(Resource.Loading(true))
  try {
- val snapshot = locationsCollection.get().await()
+ val snapshot = withContext(defaultDispatcher) { locationsCollection.get().await() }
  val locations = snapshot.toObjects<Location>()
  emit(Resource.Success(locations))
  } catch (e: Exception) {

app/src/main/java/com/juarez/upaxdemo/movies/data/MovieRepository.kt

@@ -2,58 +2,77 @@ package com.juarez.upaxdemo.movies.data
 
 import com.juarez.upaxdemo.utils.NetworkResponse
 import com.juarez.upaxdemo.utils.Resource
+import kotlinx.coroutines.CoroutineDispatcher
+import kotlinx.coroutines.Dispatchers
 import kotlinx.coroutines.flow.Flow
 import kotlinx.coroutines.flow.flow
 import kotlinx.coroutines.flow.map
+import kotlinx.coroutines.withContext
 import javax.inject.Inject
 
-class MovieRepository @Inject constructor(
+interface MovieRepository {
+ fun getAllPopularMovies(): Flow<Resource<List<Movie>>>
+ fun getAllTopRatedMovies(): Flow<Resource<List<Movie>>>
+ fun getMovieDetail(movieId: Int): Flow<Resource<Movie>>
+ val popularMovies: Flow<List<Movie>>
+ val topRatedMovies: Flow<List<Movie>>
+}
+
+class MovieRepositoryImpl @Inject constructor(
  private val remoteDataSource: MovieRemoteDataSource,
  private val localDataSource: MovieLocalDataSource,
-) {
+ private val defaultDispatcher: CoroutineDispatcher = Dispatchers.IO
+) : MovieRepository {
 
- fun getAllPopularMovies(): Flow<Resource<List<Movie>>> = flow {
+ override fun getAllPopularMovies(): Flow<Resource<List<Movie>>> = flow {
  emit(Resource.Loading(true))
  val total = localDataSource.getTotalPopularMovies()
  if (total < 1) {
- val response = remoteDataSource.getPopularMoviesAPI()
+ val response = withContext(defaultDispatcher) { remoteDataSource.getPopularMoviesAPI() }
+
  if (response is NetworkResponse.Success) {
  localDataSource.saveMovies(response.data!!.map { it.toEntity("popular") })
  } else emit(Resource.Error(response.message!!))
  }
  emit(Resource.Loading(false))
  }
 
- fun getAllTopRatedMovies(): Flow<Resource<List<Movie>>> = flow {
+ override fun getAllTopRatedMovies(): Flow<Resource<List<Movie>>> = flow {
  emit(Resource.Loading(true))
  val total = localDataSource.getTotalTopRatedMovies()
  if (total < 1) {
- val response = remoteDataSource.getTopRatedMovies()
+ val response = withContext(defaultDispatcher) { remoteDataSource.getTopRatedMovies() }
+
  if (response is NetworkResponse.Success) {
  localDataSource.saveMovies(response.data!!.map { it.toEntity("top") })
  } else emit(Resource.Error(response.message!!))
  }
  emit(Resource.Loading(false))
  }
 
- fun getMovieDetail(movieId: Int): Flow<Resource<Movie>> = flow {
+ override fun getMovieDetail(movieId: Int): Flow<Resource<Movie>> = flow {
  emit(Resource.Loading(true))
  val movie = localDataSource.getMovieById(movieId)
  if (movie != null) {
  emit(Resource.Success(movie.toModel()))
  } else {
- val response = remoteDataSource.getMovieDetail(movieId)
+ val response = withContext(defaultDispatcher) {
+ remoteDataSource.getMovieDetail(movieId)
+ }
+
  if (response is NetworkResponse.Success) emit(Resource.Success(response.data!!))
  else emit(Resource.Error(response.message!!))
  }
  emit(Resource.Loading(false))
  }
 
- val popularMovies: Flow<List<Movie>> = localDataSource.popularMovies.map { movieEntities ->
- movieEntities.map { movieEntity -> movieEntity.toModel() }
- }
+ override val popularMovies: Flow<List<Movie>> =
+ localDataSource.popularMovies.map { movieEntities ->
+ movieEntities.map { movieEntity -> movieEntity.toModel() }
+ }
 
- val topRatedMovies: Flow<List<Movie>> = localDataSource.topRatedMovies.map { movieEntities ->
- movieEntities.map { movieEntity -> movieEntity.toModel() }
- }
+ override val topRatedMovies: Flow<List<Movie>> =
+ localDataSource.topRatedMovies.map { movieEntities ->
+ movieEntities.map { movieEntity -> movieEntity.toModel() }
+ }
 }

app/src/main/java/com/juarez/upaxdemo/movies/domain/GetMovieDetailUseCase.kt

@@ -5,7 +5,9 @@ import com.juarez.upaxdemo.movies.data.MovieRepository
 import com.juarez.upaxdemo.utils.Resource
 import kotlinx.coroutines.flow.Flow
 import javax.inject.Inject
+import javax.inject.Singleton
 
+@Singleton
 class GetMovieDetailUseCase @Inject constructor(private val repository: MovieRepository) {
  operator fun invoke(movieId: Int): Flow<Resource<Movie>> = repository.getMovieDetail(movieId)
 }

app/src/main/java/com/juarez/upaxdemo/movies/domain/GetPopularMoviesUseCase.kt

@@ -5,7 +5,9 @@ import com.juarez.upaxdemo.movies.data.MovieRepository
 import com.juarez.upaxdemo.utils.Resource
 import kotlinx.coroutines.flow.Flow
 import javax.inject.Inject
+import javax.inject.Singleton
 
+@Singleton
 class GetPopularMoviesUseCase @Inject constructor(private val repository: MovieRepository) {
  operator fun invoke(): Flow<Resource<List<Movie>>> = repository.getAllPopularMovies()
 }

app/src/main/java/com/juarez/upaxdemo/movies/domain/GetTopRatedMoviesUseCase.kt

@@ -5,7 +5,9 @@ import com.juarez.upaxdemo.movies.data.MovieRepository
 import com.juarez.upaxdemo.utils.Resource
 import kotlinx.coroutines.flow.Flow
 import javax.inject.Inject
+import javax.inject.Singleton
 
+@Singleton
 class GetTopRatedMoviesUseCase @Inject constructor(private val repository: MovieRepository) {
  operator fun invoke(): Flow<Resource<List<Movie>>> = repository.getAllTopRatedMovies()
 }

app/src/main/java/com/juarez/upaxdemo/movies/domain/PopularMoviesUseCase.kt

@@ -4,7 +4,9 @@ import com.juarez.upaxdemo.movies.data.Movie
 import com.juarez.upaxdemo.movies.data.MovieRepository
 import kotlinx.coroutines.flow.Flow
 import javax.inject.Inject
+import javax.inject.Singleton
 
+@Singleton
 class PopularMoviesUseCase @Inject constructor(private val repository: MovieRepository) {
  operator fun invoke(): Flow<List<Movie>> = repository.popularMovies
 }

app/src/main/java/com/juarez/upaxdemo/movies/domain/TopRatedMoviesUseCase.kt

@@ -4,7 +4,9 @@ import com.juarez.upaxdemo.movies.data.Movie
 import com.juarez.upaxdemo.movies.data.MovieRepository
 import kotlinx.coroutines.flow.Flow
 import javax.inject.Inject
+import javax.inject.Singleton
 
+@Singleton
 class TopRatedMoviesUseCase @Inject constructor(private val repository: MovieRepository) {
  operator fun invoke(): Flow<List<Movie>> = repository.topRatedMovies
 }

app/src/main/java/com/juarez/upaxdemo/photo/data/ImagesRepository.kt

@@ -4,9 +4,12 @@ import android.net.Uri
 import com.google.firebase.storage.StorageReference
 import com.juarez.upaxdemo.utils.FirebaseResult
 import com.juarez.upaxdemo.utils.Resource
+import kotlinx.coroutines.CoroutineDispatcher
+import kotlinx.coroutines.Dispatchers
 import kotlinx.coroutines.flow.Flow
 import kotlinx.coroutines.flow.flow
 import kotlinx.coroutines.tasks.await
+import kotlinx.coroutines.withContext
 import javax.inject.Inject
 
 interface ImagesRepository {
@@ -17,17 +20,23 @@ interface ImagesRepository {
 
 class ImagesRepositoryImp @Inject constructor(
  private val storageReference: StorageReference,
+ private val defaultDispatcher: CoroutineDispatcher = Dispatchers.IO
 ) : ImagesRepository {
+
  override fun uploadImage(uri: Uri, fileName: String): Flow<Resource<Boolean>> = flow {
  emit(Resource.Loading(true))
- storageReference.child("images/${fileName}").putFile(uri).await()
+ withContext(defaultDispatcher) {
+ storageReference.child("images/${fileName}").putFile(uri).await()
+ }
  emit(Resource.Success(true))
  emit(Resource.Loading(false))
  }
 
  override fun getImages(): Flow<FirebaseResult<MutableList<Photo>>> = flow {
  emit(FirebaseResult.Loading(true))
- val images = storageReference.child("images/").listAll().await()
+ val images = withContext(defaultDispatcher) {
+ storageReference.child("images/").listAll().await()
+ }
  val imageUrls = mutableListOf<Photo>()
  images.items.forEach { img ->
  val url = img.downloadUrl.await()
@@ -41,7 +50,9 @@ class ImagesRepositoryImp @Inject constructor(
 
  override fun deleteImage(filename: String): Flow<FirebaseResult<Boolean>> = flow {
  emit(FirebaseResult.Loading(true))
- storageReference.child(("images/${filename}")).delete().await()
+ withContext(defaultDispatcher) {
+ storageReference.child(("images/${filename}")).delete().await()
+ }
  emit(FirebaseResult.Success(true))
  emit(FirebaseResult.Loading(false))
  }