ui state

data/src/main/java/com/rubylichtenstein/data/KtorHttpClient.kt

@@ -36,19 +36,19 @@ class KtorHttpClient {
 
     suspend inline fun <reified T : ApiResponse<U>, U> safeApiCall(
         apiCall: HttpClient.() -> HttpResponse
-    ): Result<U> = runCatching {
+    ): U {
         val response = apiCall.invoke(client)
-        when (response.status) {
+        return when (response.status) {
             HttpStatusCode.OK -> {
                 val obj = response.body<T>()
                 if (obj.status != "success") {
-                    throw Error("Server responded with status: ${obj.status}")
+                    error("Server responded with status: ${obj.status}")
                 } else {
                     obj.message
                 }
             }
 
-            else -> throw Error("An unknown or network error occurred")
+            else -> error("Server responded with status: ${response.status}")
         }
     }
 }

data/src/main/java/com/rubylichtenstein/data/breeds/BreedsRemoteApi.kt

@@ -1,14 +1,15 @@
 package com.rubylichtenstein.data.breeds
 
 import com.rubylichtenstein.data.KtorHttpClient
+import com.rubylichtenstein.data.images.BASE_URL
 import io.ktor.client.request.get
 import javax.inject.Inject
 
 class BreedsRemoteApi @Inject constructor(private val client: KtorHttpClient) {
 
-    suspend fun getAllBreeds(): Result<Map<String, List<String>>> {
+    suspend fun getAllBreeds(): Map<String, List<String>> {
         return client.safeApiCall {
-            get("${com.rubylichtenstein.data.images.BASE_URL}breeds/list/all")
+            get("${BASE_URL}breeds/list/all")
         }
     }
 }

data/src/main/java/com/rubylichtenstein/data/breeds/BreedsRepositoryImpl.kt

@@ -2,7 +2,7 @@ package com.rubylichtenstein.data.breeds
 
 import com.rubylichtenstein.domain.breeds.data.BreedsRepository
 import kotlinx.coroutines.flow.Flow
-import kotlinx.coroutines.flow.first
+import kotlinx.coroutines.flow.firstOrNull
 import kotlinx.coroutines.flow.flow
 import javax.inject.Inject
 import javax.inject.Singleton
@@ -22,7 +22,7 @@ class BreedsRepositoryImpl @Inject constructor(
 
         // Then always fetch from remote
         try {
-            val remoteBreeds = breedsApi.getAllBreeds().getOrThrow()
+            val remoteBreeds = breedsApi.getAllBreeds()
             val breeds = BreedInfoImpl.fromMap(remoteBreeds)
             breedsDataStore.save(breeds)
             emit(breeds)
@@ -34,7 +34,7 @@ class BreedsRepositoryImpl @Inject constructor(
     }
 
     private suspend fun getBreedsFromLocal(): List<BreedInfoImpl>? {
-        return breedsDataStore.get.first()
+        return breedsDataStore.get.firstOrNull()
     }
 }
 

data/src/main/java/com/rubylichtenstein/data/images/BreedImagesApi.kt

@@ -7,7 +7,7 @@ import javax.inject.Inject
 const val BASE_URL = "https://dog.ceo/api/"
 
 interface BreedImagesApi {
-    suspend fun getBreedImages(breed: String): Result<List<String>>
+    suspend fun getBreedImages(breed: String): List<String>
 }
 
 class BreedImagesApiImpl @Inject constructor(
@@ -29,7 +29,7 @@ class BreedImagesApiImpl @Inject constructor(
      * 2. To get images for a sub-breed:
      *      getBreedImages("shepherd/australian")
      */
-    override suspend fun getBreedImages(breed: String): Result<List<String>> {
+    override suspend fun getBreedImages(breed: String): List<String> {
         return client.safeApiCall {
             get("${BASE_URL}breed/$breed/images")
         }

data/src/main/java/com/rubylichtenstein/data/images/ImagesRepositoryImpl.kt

@@ -23,20 +23,18 @@ class ImagesRepositoryImpl @Inject constructor(
             .distinctUntilChanged()
 
     private suspend fun fetchAndSave(breedKey: String) {
-        val remoteData = getRemoteBreedImages(breedKey).getOrThrow()
+        val remoteData = getRemoteBreedImages(breedKey)
         imagesDataStore.insertAll(remoteData.map { it.fromDogImageEntity() })
     }
 
-    private suspend fun getRemoteBreedImages(breedKey: String): Result<List<DogImage>> {
-        return dogBreedApiService.getBreedImages(breedKey).map {
-            it.map { url ->
-                DogImage(
-                    breedName = buildDisplayNameFromKey(breedKey),
-                    isFavorite = false,
-                    url = url,
-                    breedKey = breedKey
-                )
-            }
+    private suspend fun getRemoteBreedImages(breedKey: String): List<DogImage> {
+        return dogBreedApiService.getBreedImages(breedKey).map { url ->
+            DogImage(
+                breedName = buildDisplayNameFromKey(breedKey),
+                isFavorite = false,
+                url = url,
+                breedKey = breedKey
+            )
         }
     }
 

ui/src/main/java/com/rubylichtenstein/ui/breeds/BreedsScreen.kt

@@ -28,8 +28,8 @@ import androidx.navigation.NavController
 import com.rubylichtenstein.domain.breeds.BreedEntity
 import com.rubylichtenstein.domain.common.capitalizeWords
 import com.rubylichtenstein.ui.Screen
-import com.rubylichtenstein.ui.common.AsyncResult
-import com.rubylichtenstein.ui.common.AsyncStateHandler
+import com.rubylichtenstein.ui.common.UiStateWrapper
+import com.rubylichtenstein.ui.common.UiState
 
 @Composable
 fun BreedsScreen(
@@ -49,7 +49,7 @@ fun BreedsScreen(
 @ExperimentalMaterial3Api
 @Composable
 fun BreedsScreen(
-    breedListState: AsyncResult<List<BreedEntity>>,
+    breedListState: UiState<List<BreedEntity>>,
     navigateToDogImages: (BreedEntity) -> Unit
 ) {
     val scrollBehavior =
@@ -71,7 +71,7 @@ fun BreedsScreen(
         }
     ) { innerPadding ->
         Box(modifier = Modifier.padding(innerPadding)) {
-            AsyncStateHandler(breedListState) { data ->
+            UiStateWrapper(breedListState) { data ->
                 BreedList(
                     breeds = data,
                     onItemClick = navigateToDogImages

ui/src/main/java/com/rubylichtenstein/ui/breeds/BreedsViewModel.kt

@@ -3,8 +3,8 @@ package com.rubylichtenstein.ui.breeds
 import androidx.lifecycle.ViewModel
 import androidx.lifecycle.viewModelScope
 import com.rubylichtenstein.domain.breeds.GetBreedsUseCase
-import com.rubylichtenstein.ui.common.AsyncResult
-import com.rubylichtenstein.ui.common.asAsyncResult
+import com.rubylichtenstein.ui.common.UiState
+import com.rubylichtenstein.ui.common.asUiState
 import dagger.hilt.android.lifecycle.HiltViewModel
 import kotlinx.coroutines.flow.SharingStarted
 import kotlinx.coroutines.flow.stateIn
@@ -16,10 +16,10 @@ class BreedsViewModel @Inject constructor(
 ) : ViewModel() {
 
     val breedsState = getBreedsUseCase()
-        .asAsyncResult()
+        .asUiState()
         .stateIn(
             viewModelScope,
             SharingStarted.Lazily,
-            AsyncResult.Loading
+            UiState.Loading
         )
 }

ui/src/main/java/com/rubylichtenstein/ui/common/UiState.kt

@@ -0,0 +1,46 @@
+package com.rubylichtenstein.ui.common
+
+import kotlinx.coroutines.flow.Flow
+import kotlinx.coroutines.flow.catch
+import kotlinx.coroutines.flow.map
+
+fun <T, R> UiState<T>.mapSuccess(transform: (T) -> R): UiState<R> {
+    return when (this) {
+        is UiState.Loading -> UiState.Loading
+        is UiState.Success -> UiState.Success(transform(data))
+        is UiState.Error -> UiState.Error(message)
+        is UiState.Empty -> UiState.Empty(message)
+    }
+}
+
+sealed interface UiState<out T> {
+    data class Success<T>(val data: T) : UiState<T>
+    data class Error(val message: String?) : UiState<Nothing>
+    data object Loading : UiState<Nothing>
+    data class Empty(val message: String?) : UiState<Nothing>
+}
+
+fun <T> Flow<T>.asUiState(
+    errorMessage: String? = null
+): Flow<UiState<T>> {
+    return this
+        .map<T, UiState<T>> {
+            UiState.Success(it)
+        }
+        .catch { emit(UiState.Error(errorMessage ?: it.message)) }
+}
+
+fun <T> Flow<List<T>>.asUiState(
+    emptyMessage: String? = null,
+    errorMessage: String? = null
+): Flow<UiState<List<T>>> {
+    return this
+        .map {
+            if (it.isEmpty()) {
+                UiState.Empty(emptyMessage)
+            } else {
+                UiState.Success(it)
+            }
+        }
+        .catch { emit(UiState.Error(errorMessage ?: it.message)) }
+}

ui/src/main/java/com/rubylichtenstein/ui/common/AsyncStateHandler.kt → ui/src/main/java/com/rubylichtenstein/ui/common/UiStateWrapper.kt

@@ -12,8 +12,8 @@ import androidx.compose.ui.text.style.TextAlign
 import androidx.compose.ui.unit.dp
 
 @Composable
-fun <T> AsyncStateHandler(
-    asyncResult: AsyncResult<T>,
+fun <T> UiStateWrapper(
+    uiState: UiState<T>,
     onError: @Composable (String) -> Unit = { message ->
         Box(modifier = Modifier.fillMaxSize(), contentAlignment = Alignment.Center) {
             Text(
@@ -28,11 +28,21 @@ fun <T> AsyncStateHandler(
             CircularProgressIndicator()
         }
     },
+    onEmpty: @Composable (String) -> Unit = {
+        Box(modifier = Modifier.fillMaxSize(), contentAlignment = Alignment.Center) {
+            Text(
+                text = it,
+                modifier = Modifier.padding(16.dp),
+                textAlign = TextAlign.Center
+            )
+        }
+    },
     onSuccess: @Composable (T) -> Unit
 ) {
-    when (asyncResult) {
-        is AsyncResult.Loading -> onLoading()
-        is AsyncResult.Success -> onSuccess(asyncResult.data)
-        is AsyncResult.Error -> onError(asyncResult.exception?.message ?: "Unknown error")
+    when (uiState) {
+        is UiState.Loading -> onLoading()
+        is UiState.Success -> onSuccess(uiState.data)
+        is UiState.Error -> onError(uiState.message ?: "Unknown error")
+        is UiState.Empty -> onEmpty(uiState.message ?: "No data")
     }
 }

ui/src/main/java/com/rubylichtenstein/ui/favorites/FavoritesPresenter.kt

@@ -7,8 +7,8 @@ import androidx.compose.runtime.mutableStateOf
 import androidx.compose.runtime.remember
 import androidx.compose.runtime.setValue
 import com.rubylichtenstein.domain.images.DogImage
-import com.rubylichtenstein.ui.common.AsyncResult
-import com.rubylichtenstein.ui.common.asAsyncResult
+import com.rubylichtenstein.ui.common.UiState
+import com.rubylichtenstein.ui.common.asUiState
 import com.rubylichtenstein.ui.common.mapSuccess
 import kotlinx.coroutines.flow.Flow
 
@@ -30,16 +30,16 @@ sealed interface Event {
 fun FavoritesPresenter(
     events: Flow<Event>,
     favoriteImagesFlow: Flow<List<DogImage>>
-): AsyncResult<FavoritesModel> {
-    var favoriteImagesResult by remember { mutableStateOf<AsyncResult<List<DogImage>>>(AsyncResult.Loading) }
+): UiState<FavoritesModel> {
+    var favoriteImagesResult by remember { mutableStateOf<UiState<Collection<DogImage>>>(UiState.Loading) }
     var filteredBreeds by remember { mutableStateOf(emptySet<String>()) }
 
     LaunchedEffect(Unit) {
         favoriteImagesFlow
-            .asAsyncResult()
+            .asUiState()
             .collect { images ->
                 favoriteImagesResult = images
-                if (images is AsyncResult.Success) {
+                if (images is UiState.Success) {
                     val chipsLabels = images.data.map { it.breedName }.toSet()
                     filteredBreeds = filteredBreeds.intersect(chipsLabels)
                 }

ui/src/main/java/com/rubylichtenstein/ui/favorites/FavoritesScreen.kt

@@ -19,8 +19,8 @@ import androidx.hilt.navigation.compose.hiltViewModel
 import androidx.lifecycle.compose.collectAsStateWithLifecycle
 import androidx.navigation.NavController
 import com.rubylichtenstein.domain.images.DogImage
-import com.rubylichtenstein.ui.common.AsyncResult
-import com.rubylichtenstein.ui.common.AsyncStateHandler
+import com.rubylichtenstein.ui.common.UiState
+import com.rubylichtenstein.ui.common.UiStateWrapper
 import com.rubylichtenstein.ui.images.DogImagesGrid
 
 @Composable
@@ -40,7 +40,7 @@ fun FavoritesScreen(
 
 @Composable
 fun PureFavoritesScreen(
-    state: AsyncResult<FavoritesModel>,
+    state: UiState<FavoritesModel>,
     navController: NavController,
     onToggleSelectedBreed: (ChipInfo) -> Unit,
     onToggleFavorite: (DogImage) -> Unit
@@ -56,7 +56,7 @@ fun PureFavoritesScreen(
         }
     ) { innerPadding ->
         Box(modifier = Modifier.padding(innerPadding)) {
-            AsyncStateHandler(state) {
+            UiStateWrapper(state) {
                 if (it.dogImages.isEmpty()) {
                     EmptyScreen()
                 } else {

ui/src/main/java/com/rubylichtenstein/ui/favorites/FavoritesViewModel.kt

@@ -5,7 +5,7 @@ import androidx.lifecycle.viewModelScope
 import com.rubylichtenstein.domain.favorites.GetFavoriteImagesUseCase
 import com.rubylichtenstein.domain.favorites.ToggleFavoriteUseCase
 import com.rubylichtenstein.domain.images.DogImage
-import com.rubylichtenstein.ui.common.AsyncResult
+import com.rubylichtenstein.ui.common.UiState
 import dagger.hilt.android.lifecycle.HiltViewModel
 import kotlinx.coroutines.flow.Flow
 import kotlinx.coroutines.flow.SharingStarted
@@ -19,10 +19,10 @@ import javax.inject.Inject
 class FavoritesViewModel @Inject constructor(
     val getFavoriteImagesUseCase: GetFavoriteImagesUseCase,
     val toggleFavoriteUseCase: ToggleFavoriteUseCase
-) : MoleculeViewModel<Event, AsyncResult<FavoritesModel>>() {
+) : MoleculeViewModel<Event, UiState<FavoritesModel>>() {
 
     @Composable
-    override fun models(events: Flow<Event>): AsyncResult<FavoritesModel> {
+    override fun models(events: Flow<Event>): UiState<FavoritesModel> {
         return FavoritesPresenter(
             events = events,
             favoriteImagesFlow = getFavoriteImagesUseCase()

ui/src/main/java/com/rubylichtenstein/ui/images/ImagesScreen.kt

@@ -25,7 +25,7 @@ import androidx.lifecycle.compose.collectAsStateWithLifecycle
 import androidx.navigation.NavController
 import com.rubylichtenstein.domain.breeds.buildDisplayName
 import com.rubylichtenstein.domain.common.capitalizeWords
-import com.rubylichtenstein.ui.common.AsyncStateHandler
+import com.rubylichtenstein.ui.common.UiStateWrapper
 import com.rubylichtenstein.ui.favorites.FavoritesViewModel
 
 @OptIn(ExperimentalMaterial3Api::class)
@@ -70,7 +70,7 @@ fun ImagesScreen(
         }
     ) { innerPadding ->
         Box(modifier = Modifier.padding(innerPadding)) {
-            AsyncStateHandler(dogImages) { dogImageList ->
+            UiStateWrapper(dogImages) { dogImageList ->
                 DogImagesGrid(
                     images = dogImageList
                 ) { dogImage -> favoritesViewModel.toggleFavorite(dogImage) }