[runtime] Change NetworkMonitor to expose a StateFlow directly (#6119)

* Change NetworkMonitor to expose a StateFlow directly * add .close() to docs
apollographql · Aug 14, 2024 · 19fc22b · 19fc22b
1 parent 98562e7
commit 19fc22b
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diff --git a/docs/source/advanced/network-connectivity.mdx b/docs/source/advanced/network-connectivity.mdx
@@ -27,6 +27,9 @@ val apolloClient = ApolloClient.Builder()
     .serverUrl("https://example.com/graphql")
     .retryOnErrorInterceptor(RetryOnErrorInterceptor(networkMonitor))
     .build()
+
+// once you're done with your `ApolloClient`
+networkMonitor.close()
 ```
 
 ### `failFastIfOffline`

diff --git a/...ime/src/commonMain/kotlin/com/apollographql/apollo/interceptor/RetryOnErrorInterceptor.kt b/...ime/src/commonMain/kotlin/com/apollographql/apollo/interceptor/RetryOnErrorInterceptor.kt
@@ -8,6 +8,7 @@ import com.apollographql.apollo.exception.ApolloException
 import com.apollographql.apollo.exception.ApolloNetworkException
 import com.apollographql.apollo.exception.OfflineException
 import com.apollographql.apollo.network.NetworkMonitor
+import com.apollographql.apollo.network.waitForNetwork
 import kotlinx.coroutines.delay
 import kotlinx.coroutines.flow.Flow
 import kotlinx.coroutines.flow.emitAll
@@ -60,7 +61,7 @@ private class DefaultRetryOnErrorInterceptorImpl(private val networkMonitor: Net
     val downStream = chain.proceed(request)
 
     return flow {
-          if (failFastIfOffline && networkMonitor?.isOnline() == false) {
+          if (failFastIfOffline && networkMonitor?.isOnline?.value == false) {
             emit((ApolloResponse.Builder(request.operation, request.requestUuid).exception(OfflineApolloException).build()))
           } else {
             emitAll(downStream)

diff --git a/...s/apollo-runtime/src/commonMain/kotlin/com/apollographql/apollo/network/NetworkMonitor.kt b/...s/apollo-runtime/src/commonMain/kotlin/com/apollographql/apollo/network/NetworkMonitor.kt
@@ -5,11 +5,14 @@ package com.apollographql.apollo.network
 
 import com.apollographql.apollo.annotations.ApolloExperimental
 import kotlinx.coroutines.flow.MutableStateFlow
+import kotlinx.coroutines.flow.StateFlow
+import kotlinx.coroutines.flow.asStateFlow
 import kotlinx.coroutines.flow.collect
 import kotlinx.coroutines.flow.first
 import kotlinx.coroutines.flow.mapNotNull
 import kotlinx.coroutines.flow.takeWhile
 import okio.Closeable
+import kotlin.js.JsName
 import kotlin.jvm.JvmMultifileClass
 import kotlin.jvm.JvmName
 
@@ -20,35 +23,35 @@ import kotlin.jvm.JvmName
 @ApolloExperimental
 interface NetworkMonitor : Closeable {
   /**
-   * The current state of the network
+   * Emits the current network state. May emit null during initialization
+   * when the current state is not known yet.
    */
-  suspend fun isOnline(): Boolean
+  val isOnline: StateFlow<Boolean?>
+}
 
-  /**
-   * Waits until [isOnline] is true
-   */
-  suspend fun waitForNetwork()
+internal suspend fun NetworkMonitor.waitForNetwork() {
+  isOnline.takeWhile { it != true }.collect()
 }
 
+/**
+ * @param networkObserverFactory a factory for a [NetworkObserver]. [networkObserverFactory] is called from a
+ * background thread.
+ */
 internal class DefaultNetworkMonitor(private val networkObserverFactory: () -> NetworkObserver) : NetworkMonitor, NetworkObserver.Listener {
   private val _isOnline: MutableStateFlow<Boolean?> = MutableStateFlow(null)
 
+  override val isOnline: StateFlow<Boolean?>
+    get() {
+      networkObserver
+      return _isOnline.asStateFlow()
+    }
+
   private val networkObserver by lazy {
     networkObserverFactory().also {
       it.setListener(this)
     }
   }
 
-  override suspend fun isOnline(): Boolean {
-    networkObserver
-    return _isOnline.mapNotNull { it }.first()
-  }
-
-  override suspend fun waitForNetwork() {
-    networkObserver
-    _isOnline.takeWhile { it != true }.collect()
-  }
-
   override fun close() {
     networkObserver.close()
   }

diff --git a/libraries/apollo-runtime/src/commonTest/kotlin/test/network/NetworkMonitorTest.kt b/libraries/apollo-runtime/src/commonTest/kotlin/test/network/NetworkMonitorTest.kt
@@ -13,11 +13,14 @@ import com.apollographql.mockserver.MockServer
 import com.apollographql.mockserver.assertNoRequest
 import com.apollographql.mockserver.enqueueString
 import com.apollographql.apollo.network.NetworkMonitor
+import com.apollographql.apollo.network.waitForNetwork
 import test.FooQuery
 import com.apollographql.apollo.testing.internal.runTest
 import kotlinx.coroutines.CoroutineScope
 import kotlinx.coroutines.flow.Flow
 import kotlinx.coroutines.flow.MutableStateFlow
+import kotlinx.coroutines.flow.StateFlow
+import kotlinx.coroutines.flow.asStateFlow
 import kotlinx.coroutines.flow.collect
 import kotlinx.coroutines.flow.emitAll
 import kotlinx.coroutines.flow.first
@@ -91,15 +94,10 @@ class NetworkMonitorTest {
 class FakeNetworkMonitor: NetworkMonitor {
   val _isOnline = MutableStateFlow(false)
 
-  override fun close() {}
-
-  override suspend fun waitForNetwork() {
-    _isOnline.takeWhile { !it }.collect()
-  }
+  override val isOnline: StateFlow<Boolean?>
+    get() = _isOnline.asStateFlow()
 
-  override suspend fun isOnline(): Boolean {
-    return _isOnline.mapNotNull { it }.first()
-  }
+  override fun close() {}
 }
 
 class NetworkMonitorInterceptor(private val networkMonitor: NetworkMonitor): ApolloInterceptor {