Add support to detect when UID2Manager finishes initializing

Author: Ian Bird

dev-app/src/main/java/com/uid2/dev/ui/MainScreenViewModel.kt

@@ -7,6 +7,7 @@ import androidx.lifecycle.viewModelScope
 import com.uid2.UID2Manager
 import com.uid2.UID2ManagerState.Established
 import com.uid2.UID2ManagerState.Expired
+import com.uid2.UID2ManagerState.Loading
 import com.uid2.UID2ManagerState.NoIdentity
 import com.uid2.UID2ManagerState.OptOut
 import com.uid2.UID2ManagerState.RefreshExpired
@@ -59,6 +60,7 @@ class MainScreenViewModel(
                 Log.d(TAG, "State Update: $state")
 
                 when (state) {
+                    is Loading -> Unit
                     is Established -> _viewState.emit(UserUpdatedState(state.identity, ESTABLISHED))
                     is Refreshed -> _viewState.emit(UserUpdatedState(state.identity, REFRESHED))
                     is NoIdentity -> _viewState.emit(UserUpdatedState(null, NO_IDENTITY))

sdk/src/main/java/com/uid2/UID2Manager.kt

@@ -4,6 +4,7 @@ import android.content.Context
 import com.uid2.UID2ManagerState.Established
 import com.uid2.UID2ManagerState.Expired
 import com.uid2.UID2ManagerState.Invalid
+import com.uid2.UID2ManagerState.Loading
 import com.uid2.UID2ManagerState.NoIdentity
 import com.uid2.UID2ManagerState.OptOut
 import com.uid2.UID2ManagerState.RefreshExpired
@@ -58,6 +59,7 @@ public interface UID2ManagerIdentityChangedListener {
  * A interface defining the flow of state communicated by the [UID2Manager].
  */
 public sealed interface UID2ManagerState {
+    public data object Loading : UID2ManagerState
     public data class Established(val identity: UID2Identity) : UID2ManagerState
     public data class Refreshed(val identity: UID2Identity) : UID2ManagerState
     public data object NoIdentity : UID2ManagerState
@@ -93,7 +95,23 @@ public class UID2Manager internal constructor(
      */
     public var onIdentityChangedListener: UID2ManagerIdentityChangedListener? = null
 
-    private val _state = MutableStateFlow<UID2ManagerState>(NoIdentity)
+    /**
+     * Gets or sets a listener which can be used to determine if the [UID2Manager] instance has finished initializing.
+     * Initializing includes any time required to restore a previously persisted [UID2Identity] from storage.
+     *
+     * If this property is set *after* initialization is complete, the callback will be invoked immediately.
+     */
+    public var onInitialized: (() -> Unit)? = null
+        set(value) {
+            field = value
+
+            // If we've already finished initializing, we should immediately invoke the callback.
+            if (initialized.isCompleted) {
+                value?.invoke()
+            }
+        }
+
+    private val _state = MutableStateFlow<UID2ManagerState>(Loading)
 
     /**
      * The flow representing the state of the UID2Manager.
@@ -135,6 +153,7 @@ public class UID2Manager internal constructor(
      */
     public val currentIdentityStatus: IdentityStatus
         get() = when (_state.value) {
+            is Loading -> NO_IDENTITY // Not available yet.
             is Established -> ESTABLISHED
             is Refreshed -> REFRESHED
             is NoIdentity -> NO_IDENTITY
@@ -164,6 +183,9 @@ public class UID2Manager internal constructor(
 
                 validateAndSetIdentity(it.first, it.second, false)
             }
+
+            // If we have a callback provided, invoke it.
+            onInitialized?.invoke()
         }
     }
 

sdk/src/test/java/com/uid2/UID2ManagerTest.kt

@@ -67,6 +67,28 @@ class UID2ManagerTest {
         manager = withManager(client, storageManager, timeUtils, testDispatcher, false, listener)
     }
 
+    @Test
+    fun `reports when initialization is complete`() = runTest(testDispatcher) {
+        var isInitialized = false
+        val onInitialized = { isInitialized = true }
+
+        val manager = UID2Manager(client, storageManager, timeUtils, testDispatcher, false, logger).apply {
+            this.checkExpiration = false
+            this.onInitialized = onInitialized
+        }
+
+        // Verify that the manager invokes our callback after it's been able to load the identity from storage.
+        assertFalse(isInitialized)
+        testDispatcher.scheduler.advanceUntilIdle()
+        assertTrue(isInitialized)
+
+        // Reset our state and re-assign the manager's callback. Verify that even though initialization is complete, our
+        // callback is invoked immediately.
+        isInitialized = false
+        manager.onInitialized = onInitialized
+        assertTrue(isInitialized)
+    }
+
     @Test
     fun `restores identity from storage`() = runTest(testDispatcher) {
         // Verify that the initial state of the manager reflects the restored Identity.
@@ -75,6 +97,19 @@ class UID2ManagerTest {
         assertEquals(initialStatus, manager.currentIdentityStatus)
     }
 
+    @Test
+    fun `set identity immediately available`() = runTest(testDispatcher) {
+        val identity = withRandomIdentity()
+
+        // By default, the Manager will have restored the previously persisted Identity. Let's reset our state so this
+        // will be a new Identity.
+        manager.resetIdentity()
+
+        // Verify that immediately after setting an identity, it's immediately available via currentIdentity.
+        manager.setIdentity(identity)
+        assertEquals(identity, manager.currentIdentity)
+    }
+
     @Test
     fun `updates identity when set`() = runTest(testDispatcher) {
         val identity = withRandomIdentity()