Fix the caching issue using official APIs

hichamboushaba · Oct 30, 2021 · 6398f5e · 6398f5e
1 parent 0aac0d2
commit 6398f5e
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Showing 4 changed files with 97 additions and 11 deletions.
diff --git a/app/src/main/java/com/hicham/flowlifecycle/FakeApi.kt b/app/src/main/java/com/hicham/flowlifecycle/FakeApi.kt
@@ -0,0 +1,26 @@
+package com.hicham.flowlifecycle
+
+import kotlin.random.Random
+
+val FAKE_DATA = listOf(
+    "Restaurant",
+    "Clothing Store",
+    "Coffee Shop",
+    "Bookstore",
+    "Pharmacy",
+    "Electronics Store",
+    "College",
+    "Fast Food Restaurant",
+    "Cupcake Shop",
+    "Furniture Store",
+    "Supermarket",
+    "Gift Shop",
+    "Kids Store"
+)
+
+class FakeApi {
+    suspend fun fetchNearbyLocations(latitude: Double, longitude: Double): List<String> {
+        val size = Random.nextInt(1, FAKE_DATA.size)
+        return FAKE_DATA.shuffled().take(size)
+    }
+}
diff --git a/app/src/main/java/com/hicham/flowlifecycle/MainFragment.kt b/app/src/main/java/com/hicham/flowlifecycle/MainFragment.kt
@@ -5,10 +5,12 @@ import android.content.pm.PackageManager.PERMISSION_GRANTED
 import android.os.Bundle
 import android.view.View
 import androidx.activity.result.contract.ActivityResultContracts
+import androidx.core.view.isVisible
 import androidx.fragment.app.Fragment
 import androidx.fragment.app.viewModels
 import androidx.lifecycle.flowWithLifecycle
 import androidx.lifecycle.lifecycleScope
+import androidx.viewbinding.ViewBinding
 import com.hicham.flowlifecycle.databinding.FragmentMainBinding
 import kotlinx.coroutines.flow.launchIn
 import kotlinx.coroutines.flow.onEach
@@ -44,8 +46,25 @@ class MainFragment : Fragment(R.layout.fragment_main) {
         viewLifecycleOwner.lifecycleScope.launch {
             viewModel.locationUpdates
                 .flowWithLifecycle(viewLifecycleOwner.lifecycle)
-                .onEach { binding.location.text = "${it.latitude} ${it.longitude}" }
+                .launchIn(this)
+            viewModel.viewState
+                .onEach { viewState ->
+                    binding.render(viewState)
+                }
                 .launchIn(this)
         }
     }
-}
+
+    private fun FragmentMainBinding.render(viewState: ViewState) {
+        progressBar.isVisible = viewState.isLoading
+        locationText.isVisible = !viewState.isLoading
+        nearbyLocations.isVisible = !viewState.isLoading
+
+        viewState.location?.let {
+            locationText.text = "${it.latitude} ${it.longitude}"
+        }
+        nearbyLocations.text = viewState.nearbyLocations.joinToString(",")
+    }
+}
+
+
diff --git a/app/src/main/java/com/hicham/flowlifecycle/MainViewModel.kt b/app/src/main/java/com/hicham/flowlifecycle/MainViewModel.kt
@@ -4,27 +4,46 @@ import android.annotation.SuppressLint
 import android.app.Application
 import android.location.Location
 import androidx.lifecycle.AndroidViewModel
-import kotlinx.coroutines.flow.Flow
-import kotlinx.coroutines.flow.MutableStateFlow
-import kotlinx.coroutines.flow.filter
-import kotlinx.coroutines.flow.flatMapLatest
+import androidx.lifecycle.viewModelScope
+import kotlinx.coroutines.channels.BufferOverflow
+import kotlinx.coroutines.flow.*
 
 class MainViewModel(application: Application) : AndroidViewModel(application) {
     private val locationObserver = LocationObserver(application)
+    private val api: FakeApi = FakeApi()
 
     private val hasLocationPermission = MutableStateFlow(false)
 
-    @SuppressLint("MissingPermission")
     val locationUpdates: Flow<Location> = hasLocationPermission
         .filter { it }
         .flatMapLatest { locationObserver.observeLocationUpdates() }
+        .onEach { currentLocation.emit(it) }
+
+    private val currentLocation = MutableSharedFlow<Location>()
+
+    val viewState: Flow<ViewState> = currentLocation
+        .mapLatest { location ->
+            val nearbyLocations = api.fetchNearbyLocations(location.latitude, location.longitude)
+            ViewState(
+                isLoading = false,
+                location = location,
+                nearbyLocations = nearbyLocations
+            )
+        }
+        .stateIn(
+            scope = viewModelScope,
+            started = SharingStarted.WhileSubscribed(stopTimeoutMillis = 5000L),
+            initialValue = ViewState(isLoading = true)
+        )
+
 
     fun onLocationPermissionGranted() {
         hasLocationPermission.value = true
     }
 }
 
 data class ViewState(
-    val location: Location,
-    val nearbyLocations: List<String>
+    val isLoading: Boolean,
+    val location: Location? = null,
+    val nearbyLocations: List<String> = emptyList()
 )
diff --git a/app/src/main/res/layout/fragment_main.xml b/app/src/main/res/layout/fragment_main.xml
@@ -1,16 +1,38 @@
 <?xml version="1.0" encoding="utf-8"?>
 <androidx.constraintlayout.widget.ConstraintLayout xmlns:android="http://schemas.android.com/apk/res/android"
     xmlns:app="http://schemas.android.com/apk/res-auto"
+    xmlns:tools="http://schemas.android.com/tools"
     android:layout_width="match_parent"
     android:layout_height="match_parent">
 
-    <androidx.appcompat.widget.AppCompatTextView
-        android:id="@+id/location"
+    <ProgressBar
+        android:id="@+id/progressBar"
         android:layout_width="wrap_content"
         android:layout_height="wrap_content"
         app:layout_constraintBottom_toBottomOf="parent"
         app:layout_constraintEnd_toEndOf="parent"
         app:layout_constraintStart_toStartOf="parent"
         app:layout_constraintTop_toTopOf="parent" />
 
+    <androidx.appcompat.widget.AppCompatTextView
+        android:id="@+id/location_text"
+        android:layout_width="wrap_content"
+        android:layout_height="wrap_content"
+        app:layout_constraintBottom_toTopOf="@id/nearby_locations"
+        app:layout_constraintEnd_toEndOf="parent"
+        app:layout_constraintStart_toStartOf="parent"
+        app:layout_constraintTop_toTopOf="parent"
+        app:layout_constraintVertical_chainStyle="packed" />
+
+    <androidx.appcompat.widget.AppCompatTextView
+        android:id="@+id/nearby_locations"
+        android:layout_width="0dp"
+        android:layout_height="wrap_content"
+        android:layout_marginTop="16dp"
+        android:textAlignment="center"
+        app:layout_constraintBottom_toBottomOf="parent"
+        app:layout_constraintEnd_toEndOf="parent"
+        app:layout_constraintStart_toStartOf="parent"
+        app:layout_constraintTop_toBottomOf="@id/location_text" />
+
 </androidx.constraintlayout.widget.ConstraintLayout>