fix(in_app_messaging): keep Android SDK artifacts off the app compile classpath (#18873)

* fix(in_app_messaging): keep Android SDK artifacts off the app compile classpath

Exporting the versionless In-App Messaging libraries made Gradle look them up with an empty version. The display callback now lives on a private object so the app no longer needs those types to compile.

* test: build in-app messaging in the smoke app

The shared tests app is the Android build that covers the plugins together. It did not depend on firebase_in_app_messaging, so this empty-version failure never ran in CI.

* fix(in_app_messaging): deliver custom display on the main thread

The Firebase SDK calls displayMessage off the main thread. Recording the message and notifying Dart now happen together on the main thread, so engine detach cannot leave that callback stranded in the pending map.

Author: SelaseKay

packages/firebase_in_app_messaging/firebase_in_app_messaging/android/build.gradle

@@ -79,10 +79,8 @@ android {
     dependencies {
       api firebaseCoreProject
       implementation platform("com.google.firebase:firebase-bom:${getRootProjectExtOrCoreProperty("FirebaseSDKVersion", firebaseCoreProject)}")
-      // `api` so app Java compilation can resolve FirebaseInAppMessagingDisplay,
-      // which the plugin class implements.
-      api 'com.google.firebase:firebase-inappmessaging'
-      api 'com.google.firebase:firebase-inappmessaging-display'
+      implementation 'com.google.firebase:firebase-inappmessaging'
+      implementation 'com.google.firebase:firebase-inappmessaging-display'
       implementation 'androidx.annotation:annotation:1.7.0'
     }
 }

packages/firebase_in_app_messaging/firebase_in_app_messaging/android/src/main/kotlin/io/flutter/plugins/firebase/inappmessaging/FirebaseInAppMessagingPlugin.kt

@@ -31,17 +31,15 @@ import io.flutter.plugins.firebase.core.FlutterFirebasePluginRegistry
 import java.lang.ref.WeakReference
 import java.util.concurrent.ConcurrentHashMap
 import java.util.concurrent.Executor
+import kotlin.jvm.Volatile
 
 /** FirebaseInAppMessagingPlugin */
 class FirebaseInAppMessagingPlugin :
-    FlutterFirebasePlugin,
-    FlutterPlugin,
-    FirebaseInAppMessagingHostApi,
-    FirebaseInAppMessagingDisplay {
+    FlutterFirebasePlugin, FlutterPlugin, FirebaseInAppMessagingHostApi {
   private var binaryMessenger: BinaryMessenger? = null
   private var flutterApi: FirebaseInAppMessagingFlutterApi? = null
   private var application: Application? = null
-  private var customDisplayEnabled = false
+  @Volatile private var customDisplayEnabled = false
   private var lifecycleRegistered = false
   private var lastActivity: WeakReference<Activity>? = null
   private val pendingDisplays = ConcurrentHashMap<String, PendingDisplay>()
@@ -81,6 +79,36 @@ class FirebaseInAppMessagingPlugin :
 
   private var eventListenersAdded = false
 
+  private val messageDisplay =
+      object : FirebaseInAppMessagingDisplay {
+        override fun displayMessage(
+            inAppMessage: InAppMessage,
+            callbacks: FirebaseInAppMessagingDisplayCallbacks,
+        ) {
+          if (!customDisplayEnabled) {
+            return
+          }
+
+          val message = toDisplayMessage(inAppMessage)
+          val actions = collectActions(inAppMessage)
+
+          mainHandler.post {
+            val api = flutterApi
+            if (api != null && customDisplayEnabled) {
+              pendingDisplays[message.campaignMetadata.campaignId] =
+                  PendingDisplay(callbacks, actions)
+              api.onMessageDisplay(message) {}
+            } else {
+              try {
+                callbacks.messageDismissed(
+                    FirebaseInAppMessagingDisplayCallbacks.InAppMessagingDismissType.AUTO,
+                )
+              } catch (_: Exception) {}
+            }
+          }
+        }
+      }
+
   private val lifecycleCallbacks =
       object : Application.ActivityLifecycleCallbacks {
         override fun onActivityCreated(activity: Activity, savedInstanceState: Bundle?) {}
@@ -90,10 +118,7 @@ class FirebaseInAppMessagingPlugin :
         override fun onActivityResumed(activity: Activity) {
           lastActivity = WeakReference(activity)
           if (customDisplayEnabled) {
-            FirebaseInAppMessaging.getInstance()
-                .setMessageDisplayComponent(
-                    this@FirebaseInAppMessagingPlugin,
-                )
+            FirebaseInAppMessaging.getInstance().setMessageDisplayComponent(messageDisplay)
           }
         }
 
@@ -130,21 +155,6 @@ class FirebaseInAppMessagingPlugin :
     FirebaseInAppMessagingHostApi.setUp(binding.binaryMessenger, null)
   }
 
-  override fun displayMessage(
-      inAppMessage: InAppMessage,
-      callbacks: FirebaseInAppMessagingDisplayCallbacks,
-  ) {
-    if (!customDisplayEnabled) {
-      return
-    }
-
-    val message = toDisplayMessage(inAppMessage)
-    pendingDisplays[message.campaignMetadata.campaignId] =
-        PendingDisplay(callbacks, collectActions(inAppMessage))
-
-    mainHandler.post { flutterApi?.onMessageDisplay(message) {} }
-  }
-
   private fun campaignMetadata(inAppMessage: InAppMessage): FiamCampaignMetadata {
     val metadata = inAppMessage.campaignMetadata
     return FiamCampaignMetadata(
@@ -305,7 +315,7 @@ class FirebaseInAppMessagingPlugin :
     customDisplayEnabled = enabled
     val fiam = FirebaseInAppMessaging.getInstance()
     if (enabled) {
-      fiam.setMessageDisplayComponent(this)
+      fiam.setMessageDisplayComponent(messageDisplay)
       if (!lifecycleRegistered) {
         application?.registerActivityLifecycleCallbacks(lifecycleCallbacks)
         lifecycleRegistered = true

tests/pubspec.yaml

@@ -35,6 +35,8 @@ dependencies:
   firebase_database: ^13.0.1
   firebase_database_platform_interface: ^0.4.2+9
   firebase_database_web: ^0.2.9+16
+  firebase_in_app_messaging: ^0.10.1
+  firebase_in_app_messaging_platform_interface: ^0.2.7+30
   firebase_messaging: ^17.0.1
   firebase_messaging_platform_interface: ^4.11.1
   firebase_messaging_web: ^4.3.1