Add IAM Lifecycle to iOS Flutter

* Add IAM Lifecycle methods to OneSignalPlugin.m
* Add OSInAppMessageLifeCycleHandler to OneSignalPlugin declaration in OneSignalPlugin.h

Author: tanaynigam

ios/Classes/OneSignalPlugin.h

@@ -28,7 +28,7 @@
 #import <Flutter/Flutter.h>
 #import <OneSignal/OneSignal.h>
 
-@interface OneSignalPlugin : NSObject<FlutterPlugin, OSSubscriptionObserver, OSPermissionObserver, OSEmailSubscriptionObserver, OSSMSSubscriptionObserver>
+@interface OneSignalPlugin : NSObject<FlutterPlugin, OSSubscriptionObserver, OSPermissionObserver, OSEmailSubscriptionObserver, OSSMSSubscriptionObserver, OSInAppMessageLifecycleHandler>
 
 // Do NOT initialize instances of this class.
 // You must only reference the shared instance.

ios/Classes/OneSignalPlugin.m

@@ -56,6 +56,12 @@ it will add the observers (ie. subscription)
 @property (strong, nonatomic) NSMutableDictionary* notificationCompletionCache;
 @property (strong, nonatomic) NSMutableDictionary* receivedNotificationCache;
 
+@property (atomic) BOOL hasSetOnWillDisplayInAppMessageHandler;
+@property (atomic) BOOL hasSetOnDidDisplayInAppMessageHandler;
+@property (atomic) BOOL hasSetOnWillDismissInAppMessageHandler;
+@property (atomic) BOOL hasSetOnDidDismissInAppMessageHandler;
+
+@property (strong, nonatomic) OSInAppMessage *inAppMessage;
 @end
 
 @implementation OneSignalPlugin
@@ -70,6 +76,10 @@ + (instancetype)sharedInstance {
         sharedInstance.notificationCompletionCache = [NSMutableDictionary new];;
         sharedInstance.hasSetInAppMessageClickedHandler = false;
         sharedInstance.hasSetNotificationWillShowInForegroundHandler = false;
+        sharedInstance.hasSetOnWillDisplayInAppMessageHandler = false;
+        sharedInstance.hasSetOnDidDisplayInAppMessageHandler = false;
+        sharedInstance.hasSetOnWillDismissInAppMessageHandler = false;
+        sharedInstance.hasSetOnDidDismissInAppMessageHandler = false;
     });
     return sharedInstance;
 }
@@ -152,6 +162,14 @@ - (void)handleMethodCall:(FlutterMethodCall*)call result:(FlutterResult)result {
         [self initNotificationWillShowInForegroundHandlerParams];
     else if ([@"OneSignal#completeNotification" isEqualToString:call.method])
         [self completeNotification:call withResult:result];
+    else if ([@"OneSignal#onWillDisplayInAppMessageHandlerParams" isEqualToString:call.method])
+        [self onWillDisplayInAppMessageHandlerParams];
+    else if ([@"OneSignal#onDidDisplayInAppMessageHandlerParams" isEqualToString:call.method])
+        [self onDidDisplayInAppMessageHandlerParams];
+    else if ([@"OneSignal#onWillDismissInAppMessageHandlerParams" isEqualToString:call.method])
+        [self onWillDismissInAppMessageHandlerParams];
+    else if ([@"OneSignal#onDidDismissInAppMessageHandlerParams" isEqualToString:call.method])
+        [self onDidDismissInAppMessageHandlerParams];
     else
         result(FlutterMethodNotImplemented);
 }
@@ -160,6 +178,8 @@ - (void)setAppId:(FlutterMethodCall *)call withResult:(FlutterResult)result {
      [OneSignal setInAppMessageClickHandler:^(OSInAppMessageAction *action) {
          [self handleInAppMessageClicked:action];
      }];
+
+    [OneSignal setInAppMessageLifecycleHandler:self];
 
     [OneSignal setAppId:call.arguments[@"appId"]];
 
@@ -399,6 +419,60 @@ - (void)handleInAppMessageClicked:(OSInAppMessageAction *)action {
     [self.channel invokeMethod:@"OneSignal#handleClickedInAppMessage" arguments:action.toJson];
 }
 
+#pragma mark In App Message lifecycle Handler
+- (void)onWillDisplayInAppMessageHandlerParams {
+    self.hasSetOnWillDisplayInAppMessageHandler = YES;
+
+    if (self.inAppMessage) {
+        [self onWillDisplayInAppMessage:self.inAppMessage];
+        self.inAppMessage = nil;
+    }
+}
+
+- (void)onDidDisplayInAppMessageHandlerParams {
+    self.hasSetOnDidDisplayInAppMessageHandler = YES;
+
+    if (self.inAppMessage) {
+        [self onDidDisplayInAppMessage:self.inAppMessage];
+        self.inAppMessage = nil;
+    }
+}
+
+- (void)onWillDismissInAppMessageHandlerParams {
+    self.hasSetOnWillDismissInAppMessageHandler = YES;
+
+    if (self.inAppMessage) {
+        [self onWillDismissInAppMessage:self.inAppMessage];
+        self.inAppMessage = nil;
+    }
+}
+
+- (void)onDidDismissInAppMessageHandlerParams {
+    self.hasSetOnDidDismissInAppMessageHandler = YES;
+
+    if (self.inAppMessage) {
+        [self onDidDismissInAppMessage:self.inAppMessage];
+        self.inAppMessage = nil;
+    }
+}
+
+#pragma mark OSInAppMessageLifeCycleHandler
+- (void)onWillDisplayInAppMessage:(OSInAppMessage *) result {
+    [self.channel invokeMethod:@"OneSignal#onWillDisplayInAppMessage" arguments:result.toJson];
+}
+
+- (void)onDidDisplayInAppMessage:(OSInAppMessage *) result {
+    [self.channel invokeMethod:@"OneSignal#onDidDisplayInAppMessage" arguments:result.toJson];
+}
+
+- (void)onWillDismissInAppMessage:(OSInAppMessage *) result {
+    [self.channel invokeMethod:@"OneSignal#onWillDismissInAppMessage" arguments:result.toJson];
+}
+
+- (void)onDidDismissInAppMessage:(OSInAppMessage *) result {
+    [self.channel invokeMethod:@"OneSignal#onDidDismissInAppMessage" arguments:result.toJson];
+}
+
 #pragma mark OSSubscriptionObserver
 - (void)onOSSubscriptionChanged:(OSSubscriptionStateChanges *)stateChanges {
    [self.channel invokeMethod:@"OneSignal#subscriptionChanged" arguments: stateChanges.toDictionary];