Fix Album & Artist crash when no network

app/src/main/java/code/name/monkey/retromusic/fragments/albums/AlbumDetailsFragment.kt

@@ -38,6 +38,7 @@ import code.name.monkey.retromusic.helper.MusicPlayerRemote
 import code.name.monkey.retromusic.helper.SortOrder
 import code.name.monkey.retromusic.model.Album
 import code.name.monkey.retromusic.model.Artist
+import code.name.monkey.retromusic.network.Result
 import code.name.monkey.retromusic.network.model.LastFmAlbum
 import code.name.monkey.retromusic.repository.RealRepository
 import code.name.monkey.retromusic.util.MusicUtil
@@ -83,15 +84,7 @@ class AlbumDetailsFragment : AbsMainActivityFragment(R.layout.fragment_album_det
             startPostponedEnterTransition()
             showAlbum(it)
         })
-        detailsViewModel.getArtist().observe(viewLifecycleOwner, Observer {
+
-            loadArtistImage(it)
-        })
-        detailsViewModel.getMoreAlbums().observe(viewLifecycleOwner, Observer {
-            moreAlbums(it)
-        })
-        detailsViewModel.getAlbumInfo().observe(viewLifecycleOwner, Observer {
-            aboutAlbum(it)
-        })
         setupRecyclerView()
         artistImage.setOnClickListener {
             requireActivity().findNavController(R.id.fragment_container)
@@ -172,8 +165,25 @@ class AlbumDetailsFragment : AbsMainActivityFragment(R.layout.fragment_album_det
         }
         loadAlbumCover(album)
         simpleSongAdapter.swapDataSet(album.songs)
-        detailsViewModel.loadArtist(album.artistId)
+        detailsViewModel.getArtist(album.artistId).observe(viewLifecycleOwner, Observer {
-        detailsViewModel.loadAlbumInfo(album)
+            loadArtistImage(it)
+        })
+        /*detailsViewModel.getMoreAlbums().observe(viewLifecycleOwner, Observer {
+            moreAlbums(it)
+        })*/
+        detailsViewModel.getAlbumInfo(album).observe(viewLifecycleOwner, Observer { result ->
+            when (result) {
+                is Result.Loading -> {
+                    println("Loading")
+                }
+                is Result.Error -> {
+                    println("Error")
+                }
+                is Result.Success -> {
+                    aboutAlbum(result.data)
+                }
+            }
+        })
     }
 
     private fun moreAlbums(albums: List<Album>) {

app/src/main/java/code/name/monkey/retromusic/fragments/albums/AlbumDetailsViewModel.kt

@@ -1,70 +1,44 @@
 package code.name.monkey.retromusic.fragments.albums
 
-import androidx.lifecycle.*
+import androidx.lifecycle.LiveData
+import androidx.lifecycle.ViewModel
+import androidx.lifecycle.liveData
 import code.name.monkey.retromusic.interfaces.MusicServiceEventListener
 import code.name.monkey.retromusic.model.Album
 import code.name.monkey.retromusic.model.Artist
+import code.name.monkey.retromusic.network.Result
 import code.name.monkey.retromusic.network.model.LastFmAlbum
 import code.name.monkey.retromusic.repository.RealRepository
-import kotlinx.coroutines.Deferred
 import kotlinx.coroutines.Dispatchers.IO
-import kotlinx.coroutines.async
-import kotlinx.coroutines.launch
 
 class AlbumDetailsViewModel(
     private val realRepository: RealRepository,
     private val albumId: Int
 ) : ViewModel(), MusicServiceEventListener {
 
-    private val _album = MutableLiveData<Album>()
-    private val _artist = MutableLiveData<Artist>()
-    private val _lastFmAlbum = MutableLiveData<LastFmAlbum>()
-    private val _moreAlbums = MutableLiveData<List<Album>>()
-
     fun getAlbum(): LiveData<Album> = liveData(IO) {
         val album = realRepository.albumByIdAsync(albumId)
         emit(album)
     }
 
-    fun getArtist(): LiveData<Artist> = _artist
+    fun getArtist(artistId: Int): LiveData<Artist> = liveData(IO) {
-    fun getAlbumInfo(): LiveData<LastFmAlbum> = _lastFmAlbum
-    fun getMoreAlbums(): LiveData<List<Album>> = _moreAlbums
-
-    init {
-        loadAlbumDetails()
-    }
-
-    fun getAlbum2() = liveData(context = viewModelScope.coroutineContext + IO) {
-        val album = realRepository.albumByIdAsync(albumId)
-        emit(album)
-    }
-
-    private fun loadAlbumDetails() = viewModelScope.launch(IO) {
-        val album = loadAlbumAsync.await() ?: throw NullPointerException("Album couldn't found")
-        _album.postValue(album)
-    }
-
-    fun loadAlbumInfo(album: Album) = viewModelScope.launch(IO) {
-        val lastFmAlbum = realRepository.albumInfo(album.artistName ?: "-", album.title ?: "-")
-        _lastFmAlbum.postValue(lastFmAlbum)
-    }
-
-    fun loadArtist(artistId: Int) = viewModelScope.launch(IO) {
         val artist = realRepository.artistById(artistId)
-        _artist.postValue(artist)
+        emit(artist)
+    }
 
+    fun getAlbumInfo(album: Album): LiveData<Result<LastFmAlbum>> = liveData {
+        emit(Result.Loading)
+        emit( realRepository.albumInfo(album.artistName ?: "-", album.title ?: "-"))
+    }
+
+    fun getMoreAlbums(artist: Artist): LiveData<List<Album>> = liveData(IO) {
         artist.albums?.filter { item -> item.id != albumId }?.let { albums ->
-            if (albums.isNotEmpty()) _moreAlbums.postValue(albums)
+            if (albums.isNotEmpty()) emit(albums)
         }
     }
 
-    private val loadAlbumAsync: Deferred<Album?>
-        get() = viewModelScope.async(IO) {
-            realRepository.albumByIdAsync(albumId)
-        }
-
     override fun onMediaStoreChanged() {
-        loadAlbumDetails()
+
     }
 
     override fun onServiceConnected() {}

app/src/main/java/code/name/monkey/retromusic/fragments/artists/ArtistDetailsFragment.kt

@@ -32,6 +32,7 @@ import code.name.monkey.retromusic.glide.ArtistGlideRequest
 import code.name.monkey.retromusic.glide.SingleColorTarget
 import code.name.monkey.retromusic.helper.MusicPlayerRemote
 import code.name.monkey.retromusic.model.Artist
+import code.name.monkey.retromusic.network.Result
 import code.name.monkey.retromusic.network.model.LastFmArtist
 import code.name.monkey.retromusic.repository.RealRepository
 import code.name.monkey.retromusic.util.CustomArtistImageUtil
@@ -77,9 +78,7 @@ class ArtistDetailsFragment : AbsMainActivityFragment(R.layout.fragment_artist_d
             showArtist(it)
             startPostponedEnterTransition()
         })
-        detailsViewModel.getArtistInfo().observe(viewLifecycleOwner, Observer {
+
-            artistInfo(it)
-        })
 
         playAction.apply {
             setOnClickListener { MusicPlayerRemote.openQueue(artist.songs, 0, true) }
@@ -140,6 +139,7 @@ class ArtistDetailsFragment : AbsMainActivityFragment(R.layout.fragment_artist_d
         albumTitle.text = albumText
         songAdapter.swapDataSet(artist.songs.sortedBy { it.trackNumber })
         artist.albums?.let { albumAdapter.swapDataSet(it) }
+
     }
 
     private fun loadBiography(
@@ -148,7 +148,14 @@ class ArtistDetailsFragment : AbsMainActivityFragment(R.layout.fragment_artist_d
     ) {
         biography = null
         this.lang = lang
-        detailsViewModel.loadBiography(name, lang, null)
+        detailsViewModel.getArtistInfo(name, lang, null)
+            .observe(viewLifecycleOwner, Observer { result ->
+                when (result) {
+                    is Result.Loading -> println("Loading")
+                    is Result.Error -> println("Error")
+                    is Result.Success -> artistInfo(result.data)
+                }
+            })
     }
 
     private fun artistInfo(lastFmArtist: LastFmArtist?) {

app/src/main/java/code/name/monkey/retromusic/fragments/artists/ArtistDetailsViewModel.kt

@@ -1,51 +1,37 @@
 package code.name.monkey.retromusic.fragments.artists
 
 import androidx.lifecycle.LiveData
-import androidx.lifecycle.MutableLiveData
 import androidx.lifecycle.ViewModel
-import androidx.lifecycle.viewModelScope
+import androidx.lifecycle.liveData
 import code.name.monkey.retromusic.interfaces.MusicServiceEventListener
 import code.name.monkey.retromusic.model.Artist
+import code.name.monkey.retromusic.network.Result
 import code.name.monkey.retromusic.network.model.LastFmArtist
 import code.name.monkey.retromusic.repository.RealRepository
-import kotlinx.coroutines.Deferred
+import kotlinx.coroutines.Dispatchers.IO
-import kotlinx.coroutines.Dispatchers
-import kotlinx.coroutines.async
-import kotlinx.coroutines.launch
 
 class ArtistDetailsViewModel(
     private val realRepository: RealRepository,
     private val artistId: Int
 ) : ViewModel(), MusicServiceEventListener {
 
-    private val loadArtistDetailsAsync: Deferred<Artist?>
+    fun getArtist(): LiveData<Artist> = liveData(IO) {
-        get() = viewModelScope.async(Dispatchers.IO) {
+        val artist = realRepository.artistById(artistId)
-            realRepository.artistById(artistId)
+        emit(artist)
     }
 
-    private val _artist = MutableLiveData<Artist>()
+    fun getArtistInfo(
-    private val _lastFmArtist = MutableLiveData<LastFmArtist>()
+        name: String,
-
+        lang: String?,
-    fun getArtist(): LiveData<Artist> = _artist
+        cache: String?
-    fun getArtistInfo(): LiveData<LastFmArtist> = _lastFmArtist
+    ): LiveData<Result<LastFmArtist>> = liveData(IO) {
-
+        emit(Result.Loading)
-    init {
-        loadArtistDetails()
-    }
-
-    private fun loadArtistDetails() = viewModelScope.launch {
-        val artist =
-            loadArtistDetailsAsync.await() ?: throw NullPointerException("Album couldn't found")
-        _artist.postValue(artist)
-    }
-
-    fun loadBiography(name: String, lang: String?, cache: String?) = viewModelScope.launch {
         val info = realRepository.artistInfo(name, lang, cache)
-        _lastFmArtist.postValue(info)
+        emit(info)
     }
 
     override fun onMediaStoreChanged() {
-        loadArtistDetails()
+        getArtist()
     }
 
     override fun onServiceConnected() {}

app/src/main/java/code/name/monkey/retromusic/network/Result.kt

@@ -13,7 +13,7 @@
  * See the License for the specific language governing permissions and
  * limitations under the License.
  */
-package code.name.monkey.retromusic
+package code.name.monkey.retromusic.network
 
 /**
  * Generic class that holds the network state

app/src/main/java/code/name/monkey/retromusic/repository/Repository.kt

@@ -21,6 +21,7 @@ import code.name.monkey.retromusic.db.*
 import code.name.monkey.retromusic.model.*
 import code.name.monkey.retromusic.model.smartplaylist.NotPlayedPlaylist
 import code.name.monkey.retromusic.network.LastFMService
+import code.name.monkey.retromusic.network.Result
 import code.name.monkey.retromusic.network.model.LastFmAlbum
 import code.name.monkey.retromusic.network.model.LastFmArtist
 import kotlinx.coroutines.ExperimentalCoroutinesApi
@@ -48,8 +49,8 @@ interface Repository {
     suspend fun search(query: String?): MutableList<Any>
     suspend fun getPlaylistSongs(playlist: Playlist): List<Song>
     suspend fun getGenre(genreId: Int): List<Song>
-    suspend fun artistInfo(name: String, lang: String?, cache: String?): LastFmArtist
+    suspend fun artistInfo(name: String, lang: String?, cache: String?): Result<LastFmArtist>
-    suspend fun albumInfo(artist: String, album: String): LastFmAlbum
+    suspend fun albumInfo(artist: String, album: String): Result<LastFmAlbum>
     suspend fun artistById(artistId: Int): Artist
     suspend fun recentArtists(): List<Artist>
     suspend fun topArtists(): List<Artist>
@@ -110,7 +111,9 @@ class RealRepository(
     override suspend fun fetchAlbums(): List<Album> = albumRepository.albums()
 
     override suspend fun albumByIdAsync(albumId: Int): Album = albumRepository.album(albumId)
+
     override fun albumById(albumId: Int): Album = albumRepository.album(albumId)
+
     override suspend fun fetchArtists(): List<Artist> = artistRepository.artists()
 
     override suspend fun albumArtists(): List<Artist> = artistRepository.albumArtists()
@@ -147,17 +150,29 @@ class RealRepository(
         name: String,
         lang: String?,
         cache: String?
-    ): LastFmArtist = lastFMService.artistInfo(name, lang, cache)
+    ): Result<LastFmArtist> {
+        return try {
+            Result.Success(lastFMService.artistInfo(name, lang, cache))
+        } catch (e: Exception) {
+            Result.Error
+        }
+    }
 
     override suspend fun albumInfo(
         artist: String,
         album: String
-    ): LastFmAlbum = lastFMService.albumInfo(artist, album)
+    ): Result<LastFmAlbum> {
+        return try {
+            val lastFmAlbum = lastFMService.albumInfo(artist, album)
+            Result.Success(lastFmAlbum)
+        } catch (e: Exception) {
+            Result.Error
+        }
+    }
 
     @ExperimentalCoroutinesApi
     override suspend fun homeSectionsFlow(): Flow<Result<List<Home>>> {
         val homes = MutableStateFlow<Result<List<Home>>>(value = Result.Loading)
-        println("homeSections:Loading")
         val homeSections = mutableListOf<Home>()
         val sections = listOf(
             topArtistsHome(),