Add Timeout

• Adds a 25 second timeout to make sure that even if an app implements the OSNotificationDisplayTypeDelegate but doesn't execute the callback, the SDK will timeout and will still show the notification
• The complicating factor is that multiple notifications can arrive rapidly, so the app needs to be able to map the correct display types to previously received notifications.
• TODO: Before this PR gets reviewed, I've been working on a test for the timeout edge case but it is a complex timing situation so this test will be added in the next day or two.

Author: Nightsd01

iOS_SDK/OneSignalSDK/Source/OneSignal.m

@@ -201,7 +201,9 @@ @implementation OneSignal
 // Display type is used in multiple areas of the SDK
 // To avoid calling the delegate multiple times, we store
 // the type and notification ID for each notification
+// These data structures *MUST* be accessed on the main thread only
 static NSMutableDictionary<NSString *, NSNumber *> *_displayTypeMap;
+static NSMutableDictionary<NSString *, NSMutableArray<OSNotificationDisplayTypeResponse> *> *_pendingDisplayTypeCallbacks;
 
 static OSNotificationDisplayType _inFocusDisplayType = OSNotificationDisplayTypeInAppAlert;
 + (void)setInFocusDisplayType:(OSNotificationDisplayType)value {
@@ -403,6 +405,7 @@ + (void)clearStatics {
 
     _displayDelegate = nil;
     _displayTypeMap = [NSMutableDictionary new];
+    _pendingDisplayTypeCallbacks = [NSMutableDictionary new];
 }
 
 // Set to false as soon as it's read.
@@ -1759,6 +1762,12 @@ + (void)setLastnonActiveMessageId:(NSString*)value { _lastnonActiveMessageId = v
 
 + (void)displayTypeForNotificationPayload:(NSDictionary *)payload withCompletion:(OSNotificationDisplayTypeResponse)completion {
     [OneSignalHelper runOnMainThread:^{
+        if (!_displayTypeMap)
+            _displayTypeMap = [NSMutableDictionary new];
+        
+        if (!_pendingDisplayTypeCallbacks)
+            _pendingDisplayTypeCallbacks = [NSMutableDictionary new];
+        
         var type = self.inFocusDisplayType;
 
         // check to make sure the app is in focus and it's a OneSignal notification
@@ -1773,23 +1782,64 @@ + (void)displayTypeForNotificationPayload:(NSDictionary *)payload withCompletion
         let notificationId = osPayload.notificationID;
 
         // Prevent calling the delegate multiple times for the same payload
-        if (_displayTypeMap[osPayload.notificationID]) {
+        // Checks to see if there is a pending delegate request
+        if (_pendingDisplayTypeCallbacks[notificationId]) {
+            [_pendingDisplayTypeCallbacks[notificationId] addObject:completion];
+            // checks to see if the delegate already responded for this notification
+        } else if (_displayTypeMap[osPayload.notificationID]) {
             type = (OSNotificationDisplayType)[_displayTypeMap[osPayload.notificationID] intValue];
             completion(type);
         } else if (_displayDelegate) {
+            NSMutableArray *callbacks = [NSMutableArray new];
+            [callbacks addObject:completion];
+            [_pendingDisplayTypeCallbacks setObject:callbacks forKey:notificationId];
+            
+            NSTimer *watchdogTimer = [NSTimer scheduledTimerWithTimeInterval:CUSTOM_DISPLAY_TYPE_TIMEOUT
+                                                                      target:self
+                                                                    selector:@selector(watchdogTimerFired:)
+                                                                    userInfo:notificationId
+                                                                     repeats:false];
+            
             [_displayDelegate willPresentInFocusNotificationWithPayload:osPayload withDefaultDisplayType:type withCompletion:^(OSNotificationDisplayType displayType) {
                 [OneSignalHelper runOnMainThread:^{
+                    NSMutableArray<OSNotificationDisplayTypeResponse> *callbacks = _pendingDisplayTypeCallbacks[notificationId];
+                    
+                    if (!callbacks || callbacks.count == 0)
+                        return;
+                    
+                    [watchdogTimer invalidate];
+                    [_pendingDisplayTypeCallbacks removeObjectForKey:notificationId];
                     _displayTypeMap[notificationId] = @((int)displayType);
-                    completion(displayType);
+                    
+                    for (OSNotificationDisplayTypeResponse callback in callbacks)
+                        callback(displayType);
                 }];
             }];
         } else {
+            // No delegate is set; uses the main display type set with OneSignal.setInFocusDisplayType()
             _displayTypeMap[notificationId] = @((int)type);
             completion(type);
         }
     }];
 }
 
+// If this is called, it means OSNotificationDisplayTypeDelegate did not execute the callback
+// within the max time range, and timed out. We must display the notification anyways
+// using the default display type to avoid dropping notifications.
++ (void)watchdogTimerFired:(NSTimer *)timer {
+    NSString *notificationId = (NSString *)timer.userInfo;
+    NSMutableArray<OSNotificationDisplayTypeResponse> *callbacks = _pendingDisplayTypeCallbacks[notificationId];
+    
+    // Check just in case the app called the callback just as this timer fired
+    if (!callbacks || callbacks.count == 0)
+        return;
+    
+    [_pendingDisplayTypeCallbacks removeObjectForKey:notificationId];
+    
+    for (OSNotificationDisplayTypeResponse completion in callbacks)
+        completion(_inFocusDisplayType);
+}
+
 // Entry point for the following:
 //  - 1. (iOS all) - Opening notifications
 //  - 2. Notification received

iOS_SDK/OneSignalSDK/Source/OneSignalCommonDefines.h

@@ -130,6 +130,10 @@ typedef enum {GET, POST, HEAD, PUT, DELETE, OPTIONS, CONNECT, TRACE} HTTPMethod;
 
     // the max number of UNNotificationCategory ID's the SDK will register
     #define MAX_CATEGORIES_SIZE 128
+
+    // Defines how long the SDK will wait for OSNotificationDisplayTypeDelegate to execute
+    // the callback to set the display type for a given notification
+    #define CUSTOM_DISPLAY_TYPE_TIMEOUT 25.0
 #else
     // Test defines for API Client
     #define REATTEMPT_DELAY 0.004
@@ -142,6 +146,10 @@ typedef enum {GET, POST, HEAD, PUT, DELETE, OPTIONS, CONNECT, TRACE} HTTPMethod;
 
     // the max number of UNNotificationCategory ID's the SDK will register
     #define MAX_CATEGORIES_SIZE 5
+
+    // Defines how long the SDK will wait for OSNotificationDisplayTypeDelegate to execute
+    // the callback to set the display type for a given notification
+    #define CUSTOM_DISPLAY_TYPE_TIMEOUT 0.2
 #endif
 
 // A max timeout for a request, which might include multiple reattempts

iOS_SDK/OneSignalSDK/UnitTests/DummyNotificationDisplayTypeDelegate.h

@@ -36,6 +36,8 @@ NS_ASSUME_NONNULL_BEGIN
 
 @property (nonatomic) OSNotificationDisplayType overrideDisplayType;
 
+@property (nonatomic) BOOL shouldFireCompletionBlock;
+
 // Each time the OSNotificationDisplayTypeDelegate.willPresentNotificationWithPayload()
 // method is called, this int is incremented
 @property (nonatomic) int numberOfCalls;

iOS_SDK/OneSignalSDK/UnitTests/DummyNotificationDisplayTypeDelegate.m

@@ -31,16 +31,19 @@
 @implementation DummyNotificationDisplayTypeDelegate
 
 - (instancetype)init {
-    if (self = [super init])
+    if (self = [super init]) {
         _numberOfCalls = 0;
+        _shouldFireCompletionBlock = false;
+    }
 
     return self;
 }
 
 - (void)willPresentInFocusNotificationWithPayload:(OSNotificationPayload *)payload withDefaultDisplayType:(OSNotificationDisplayType)displayType withCompletion:(OSNotificationDisplayTypeResponse)completion {
     _notificationId = payload.notificationID;
 
-    completion(_overrideDisplayType);
+    if (_shouldFireCompletionBlock)
+        completion(_overrideDisplayType);
 
     _numberOfCalls += 1;
 }

iOS_SDK/OneSignalSDK/UnitTests/UnitTests.m

@@ -2076,7 +2076,7 @@ - (void)testRegistersAfterNoApnsResponse {
         [expectation fulfill];
     });
 
-    [self waitForExpectations:@[expectation] timeout:0.1];
+    [self waitForExpectations:@[expectation] timeout:0.2];
 
     // If APNS didn't respond within X seconds, the SDK
     // should have registered the user with OneSignal
@@ -2278,9 +2278,7 @@ - (void)testNotificationWithButtonsRegistersUniqueCategory {
     XCTAssertEqualObjects(content.categoryIdentifier, @"__onesignal__dynamic__b2f7f966-d8cc-11e4-bed1-df8f05be55ba");
 }
 
-- (void)testOverrideNotificationDisplayType {
-    let dummyDelegate = [DummyNotificationDisplayTypeDelegate new];
-    
+- (NSDictionary *)setUpNotificationDisplayTypeTestWithDummyDelegate:(DummyNotificationDisplayTypeDelegate *)dummyDelegate withDisplayType:(OSNotificationDisplayType)displayType {
     id userInfo = @{@"aps": @{
                             @"mutable-content": @1,
                             @"alert": @{@"body": @"Message Body", @"title": @"title"},
@@ -2291,25 +2289,30 @@ - (void)testOverrideNotificationDisplayType {
                             @"buttons": @[@{@"i": @"id1", @"n": @"text1"}],
                             }};
 
-    __block BOOL openedWasFire = false;
-    id receiveBlock = ^(OSNotificationOpenedResult *result) {
-        openedWasFire = true;
-    };
-    
-    [OneSignal initWithLaunchOptions:nil appId:@"b2f7f966-d8cc-11e4-bed1-df8f05be55ba" handleNotificationAction:receiveBlock];
+    [OneSignal initWithLaunchOptions:nil appId:@"b2f7f966-d8cc-11e4-bed1-df8f05be55ba" handleNotificationAction:nil];
 
     [OneSignal setNotificationDisplayTypeDelegate:dummyDelegate];
 
-    [OneSignal setInFocusDisplayType:OSNotificationDisplayTypeNone];
+    [OneSignal setInFocusDisplayType:displayType];
 
     UIApplicationOverrider.currentUIApplicationState = UIApplicationStateActive;
 
     [UnitTestCommonMethods resumeApp];
     [UnitTestCommonMethods runBackgroundThreads];
 
-    // Even though the display type is set to None, this should
+    return userInfo;
+}
+
+- (void)testOverrideNotificationDisplayType {
+    let dummyDelegate = [DummyNotificationDisplayTypeDelegate new];
+    
+    // Even though the display type will be set to None, this should
     // cause the SDK to present this notification as an alert
     dummyDelegate.overrideDisplayType = OSNotificationDisplayTypeInAppAlert;
+    dummyDelegate.shouldFireCompletionBlock = true;
+    
+    let userInfo = [self setUpNotificationDisplayTypeTestWithDummyDelegate:dummyDelegate
+                                                           withDisplayType:OSNotificationDisplayTypeNone];
 
     id notifResponse = [UnitTestCommonMethods createBasiciOSNotificationResponseWithPayload:userInfo];
     [notifResponse setValue:@"id1" forKeyPath:@"actionIdentifier"];