Improve the structure of BreedDetails code

tooploox · Jun 16, 2023 · aea43f6 · aea43f6
1 parent e36923d
commit aea43f6
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Showing 4 changed files with 47 additions and 35 deletions.
diff --git a/app/src/main/kotlin/co/touchlab/kampkit/android/ui/BreedDetailsScreen.kt b/app/src/main/kotlin/co/touchlab/kampkit/android/ui/BreedDetailsScreen.kt
@@ -1,8 +1,13 @@
 package co.touchlab.kampkit.android.ui
 
+import androidx.compose.foundation.layout.Box
+import androidx.compose.foundation.layout.fillMaxSize
 import androidx.compose.material.Text
 import androidx.compose.runtime.Composable
 import androidx.compose.runtime.getValue
+import androidx.compose.ui.Alignment
+import androidx.compose.ui.Modifier
+import androidx.compose.ui.graphics.Color
 import androidx.lifecycle.compose.collectAsStateWithLifecycle
 import co.touchlab.kampkit.ui.breedDetails.BreedDetailsViewModel
 import co.touchlab.kermit.Logger
@@ -13,6 +18,13 @@ fun BreedDetailsScreen(
     log: Logger
 ) {
     val state by viewModel.detailsState.collectAsStateWithLifecycle()
+    Box(Modifier.fillMaxSize()) {
+        state.error?.let { error ->
+            Text(error, Modifier.align(Alignment.Center), color = Color.Red)
+        }
+        if (state.error == null) {
+            Text(state.breed.name, Modifier.align(Alignment.Center))
+        }
+    }
 
-    Text("${state.breed?.name }")
 }
diff --git a/shared/src/commonMain/kotlin/co/touchlab/kampkit/ui/breedDetails/BreedDetailsViewModel.kt b/shared/src/commonMain/kotlin/co/touchlab/kampkit/ui/breedDetails/BreedDetailsViewModel.kt
@@ -2,13 +2,10 @@ package co.touchlab.kampkit.ui.breedDetails
 
 import co.touchlab.kampkit.core.ViewModel
 import co.touchlab.kampkit.data.dog.DogRepository
-import co.touchlab.kampkit.db.Breed
 import co.touchlab.kermit.Logger
 import com.rickclephas.kmp.nativecoroutines.NativeCoroutinesState
 import kotlinx.coroutines.flow.MutableStateFlow
 import kotlinx.coroutines.flow.StateFlow
-import kotlinx.coroutines.flow.combine
-import kotlinx.coroutines.flow.flow
 import kotlinx.coroutines.flow.update
 import kotlinx.coroutines.launch
 
@@ -26,42 +23,23 @@ class BreedDetailsViewModel(
     val detailsState: StateFlow<BreedDetailsViewState> = mutableDetailsState
 
     init {
-        observeDetails()
+        loadDetails()
     }
 
-    private fun observeDetails() {
-        // Refresh breeds, and emit any exception that was thrown so we can handle it downstream
-        val refreshFlow = flow<Throwable?> {
-            try {
-                dogRepository.refreshBreedsIfStale()
-                emit(null)
-            } catch (exception: Exception) {
-                emit(exception)
-            }
-        }
-
+    private fun loadDetails() {
         viewModelScope.launch {
-            combine(refreshFlow, dogRepository.getBreed(breedId)) { throwable, breed -> throwable to breed }
-                .collect { (error, breed) ->
-                    mutableDetailsState.update { previousState ->
-                        val errorMessage = if (error != null) {
-                            "Unable to download breed details"
-                        } else {
-                            previousState.error
-                        }
-                        previousState.copy(
-                            isLoading = false,
-                            breed = breed,
-                            error = errorMessage.takeIf { breed != null },
-                        )
-                    }
+            dogRepository.getBreed(breedId).collect { breed ->
+                mutableDetailsState.update { previousState ->
+                    val error = if (breed == null) "Couldn't load the breed details" else null
+                    val newBreed = breed?.toDisplayable() ?: previousState.breed
+                    previousState.copy(
+                        isLoading = false,
+                        breed = newBreed,
+                        error = error
+                    )
                 }
+            }
         }
     }
 }
 
-data class BreedDetailsViewState(
-    val breed: Breed? = null,
-    val error: String? = null,
-    val isLoading: Boolean = false,
-)
diff --git a/shared/src/commonMain/kotlin/co/touchlab/kampkit/ui/breedDetails/BreedDetailsViewState.kt b/shared/src/commonMain/kotlin/co/touchlab/kampkit/ui/breedDetails/BreedDetailsViewState.kt
@@ -0,0 +1,7 @@
+package co.touchlab.kampkit.ui.breedDetails
+
+data class BreedDetailsViewState(
+    val breed: BreedDisplayable = BreedDisplayable(),
+    val error: String? = null,
+    val isLoading: Boolean = false,
+)
diff --git a/shared/src/commonMain/kotlin/co/touchlab/kampkit/ui/breedDetails/BreedDisplayable.kt b/shared/src/commonMain/kotlin/co/touchlab/kampkit/ui/breedDetails/BreedDisplayable.kt
@@ -0,0 +1,15 @@
+package co.touchlab.kampkit.ui.breedDetails
+
+import co.touchlab.kampkit.db.Breed
+
+data class BreedDisplayable(
+    val id: Long = 0,
+    val name: String = "",
+    val favorite: Boolean = false
+)
+
+fun Breed.toDisplayable() = BreedDisplayable(
+    this.id,
+    this.name,
+    this.favorite
+)