feat(logging): add public log listener methods

iOS_SDK/OneSignalDevApp/OneSignalDevApp/AppDelegate.h

@@ -31,7 +31,7 @@
 #import <UIKit/UIKit.h>
 #import <OneSignalFramework/OneSignalFramework.h>
 
-@interface AppDelegate : UIResponder <UIApplicationDelegate, OSNotificationPermissionObserver, OSInAppMessageLifecycleListener, OSPushSubscriptionObserver, OSNotificationLifecycleListener, OSInAppMessageClickListener, OSNotificationClickListener, OSUserStateObserver>
+@interface AppDelegate : UIResponder <UIApplicationDelegate, OSNotificationPermissionObserver, OSInAppMessageLifecycleListener, OSPushSubscriptionObserver, OSNotificationLifecycleListener, OSInAppMessageClickListener, OSNotificationClickListener, OSUserStateObserver, OSLogListener>
 
 @property (strong, nonatomic) UIWindow *window;
 

iOS_SDK/OneSignalDevApp/OneSignalDevApp/AppDelegate.m

@@ -51,6 +51,8 @@ - (BOOL)application:(UIApplication *)application didFinishLaunchingWithOptions:(
 //    [FIRApp configure];
 
     NSLog(@"Bundle URL: %@", [[NSBundle mainBundle] bundleURL]);
+    // Uncomment to test LogListener
+    // [OneSignal.Debug addLogListener:self];
     [OneSignal.Debug setLogLevel:ONE_S_LL_VERBOSE];
     [OneSignal.Debug setAlertLevel:ONE_S_LL_NONE];
 
@@ -194,4 +196,8 @@ - (void)application:(UIApplication *)application
     completionHandler(UIBackgroundFetchResultNoData);
 }
 
+- (void)onLogEvent:(OneSignalLogEvent * _Nonnull)event {
+    NSLog(@"Dev App onLogEvent: %@", event.entry);
+}
+
 @end

iOS_SDK/OneSignalDevApp/OneSignalDevApp/SwiftTest.swift

@@ -28,9 +28,15 @@
 import Foundation
 import OneSignalFramework
 
-class SwiftTest: NSObject {
+class SwiftTest: NSObject, OSLogListener {
+    func onLogEvent(_ event: OneSignalLogEvent) {
+        print("Dev App onLogEvent: \(event.level) - \(event.entry)")
+    }
+
     func testSwiftUserModel() {
         let token1 = OneSignal.User.pushSubscription.token
         let token = OneSignal.User.pushSubscription.token
+        OneSignal.Debug.addLogListener(self)
+        OneSignal.Debug.removeLogListener(self)
     }
 }

iOS_SDK/OneSignalSDK/OneSignal.xcodeproj/project.pbxproj

@@ -86,6 +86,9 @@
 		3C47A975292642B100312125 /* OneSignalConfigManager.m in Sources */ = {isa = PBXBuildFile; fileRef = 3C47A973292642B100312125 /* OneSignalConfigManager.m */; };
 		3C4F9E4428A4466C009F453A /* OSOperationRepo.swift in Sources */ = {isa = PBXBuildFile; fileRef = 3C4F9E4328A4466C009F453A /* OSOperationRepo.swift */; };
 		3C5117172B15C31E00563465 /* OSUserState.swift in Sources */ = {isa = PBXBuildFile; fileRef = 3C5117162B15C31E00563465 /* OSUserState.swift */; };
+		3C5501402E09CF0100E77DF7 /* OSCopyOnWriteSet.h in Headers */ = {isa = PBXBuildFile; fileRef = 3C55013E2E09CF0100E77DF7 /* OSCopyOnWriteSet.h */; };
+		3C5501412E09CF0100E77DF7 /* OSCopyOnWriteSet.m in Sources */ = {isa = PBXBuildFile; fileRef = 3C55013F2E09CF0100E77DF7 /* OSCopyOnWriteSet.m */; };
+		3C5501432E09F3D900E77DF7 /* LoggingTests.swift in Sources */ = {isa = PBXBuildFile; fileRef = 3C5501422E09F3D900E77DF7 /* LoggingTests.swift */; };
 		3C62999F2BEEA34800649187 /* PrivacyInfo.xcprivacy in Resources */ = {isa = PBXBuildFile; fileRef = 3C62999E2BEEA34800649187 /* PrivacyInfo.xcprivacy */; };
 		3C6299A12BEEA38100649187 /* PrivacyInfo.xcprivacy in Resources */ = {isa = PBXBuildFile; fileRef = 3C6299A02BEEA38100649187 /* PrivacyInfo.xcprivacy */; };
 		3C6299A32BEEA3CC00649187 /* PrivacyInfo.xcprivacy in Resources */ = {isa = PBXBuildFile; fileRef = 3C6299A22BEEA3CC00649187 /* PrivacyInfo.xcprivacy */; };
@@ -1262,6 +1265,9 @@
 		3C47A973292642B100312125 /* OneSignalConfigManager.m */ = {isa = PBXFileReference; lastKnownFileType = sourcecode.c.objc; path = OneSignalConfigManager.m; sourceTree = "<group>"; };
 		3C4F9E4328A4466C009F453A /* OSOperationRepo.swift */ = {isa = PBXFileReference; lastKnownFileType = sourcecode.swift; path = OSOperationRepo.swift; sourceTree = "<group>"; };
 		3C5117162B15C31E00563465 /* OSUserState.swift */ = {isa = PBXFileReference; lastKnownFileType = sourcecode.swift; path = OSUserState.swift; sourceTree = "<group>"; };
+		3C55013E2E09CF0100E77DF7 /* OSCopyOnWriteSet.h */ = {isa = PBXFileReference; lastKnownFileType = sourcecode.c.h; path = OSCopyOnWriteSet.h; sourceTree = "<group>"; };
+		3C55013F2E09CF0100E77DF7 /* OSCopyOnWriteSet.m */ = {isa = PBXFileReference; lastKnownFileType = sourcecode.c.objc; path = OSCopyOnWriteSet.m; sourceTree = "<group>"; };
+		3C5501422E09F3D900E77DF7 /* LoggingTests.swift */ = {isa = PBXFileReference; lastKnownFileType = sourcecode.swift; path = LoggingTests.swift; sourceTree = "<group>"; };
 		3C62999E2BEEA34800649187 /* PrivacyInfo.xcprivacy */ = {isa = PBXFileReference; lastKnownFileType = text.xml; path = PrivacyInfo.xcprivacy; sourceTree = "<group>"; };
 		3C6299A02BEEA38100649187 /* PrivacyInfo.xcprivacy */ = {isa = PBXFileReference; lastKnownFileType = text.xml; path = PrivacyInfo.xcprivacy; sourceTree = "<group>"; };
 		3C6299A22BEEA3CC00649187 /* PrivacyInfo.xcprivacy */ = {isa = PBXFileReference; lastKnownFileType = text.xml; path = PrivacyInfo.xcprivacy; sourceTree = "<group>"; };
@@ -2186,6 +2192,7 @@
 			isa = PBXGroup;
 			children = (
 				3CC063A62B6D7A8E002BB07F /* OneSignalCoreTests.swift */,
+				3C5501422E09F3D900E77DF7 /* LoggingTests.swift */,
 				3C24B0EB2BD09D7A0052E771 /* OneSignalCoreObjCTests.m */,
 				3C24B0EA2BD09D790052E771 /* OneSignalCoreTests-Bridging-Header.h */,
 			);
@@ -2615,9 +2622,9 @@
 				4529DF0B1FA932AC00CEAB1D /* OneSignalTrackFirebaseAnalytics.m */,
 				DE7D1831270279D9002D3A5D /* OSNotificationClasses.h */,
 				DE7D183527027AA0002D3A5D /* OneSignalLog.h */,
+				DE7D183327027A73002D3A5D /* OneSignalLog.m */,
 				3CCF44BC299B17290021964D /* OneSignalWrapper.h */,
 				3CCF44BD299B17290021964D /* OneSignalWrapper.m */,
-				DE7D183327027A73002D3A5D /* OneSignalLog.m */,
 				DE7D187627037A16002D3A5D /* OneSignalCoreHelper.h */,
 				DE7D187827037A26002D3A5D /* OneSignalCoreHelper.m */,
 				7AE28B8725B8ADF400529100 /* OSMacros.h */,
@@ -2632,6 +2639,8 @@
 				DEBAAEB42A436D5D00BF2C1C /* OSStubLocation.m */,
 				DEBA2A272C24D0ED00E234DB /* OSBundleUtils.h */,
 				DEBA2A252C20E9AA00E234DB /* OSBundleUtils.m */,
+				3C55013E2E09CF0100E77DF7 /* OSCopyOnWriteSet.h */,
+				3C55013F2E09CF0100E77DF7 /* OSCopyOnWriteSet.m */,
 			);
 			path = Source;
 			sourceTree = "<group>";
@@ -3157,6 +3166,7 @@
 				DE7D182A270271A9002D3A5D /* OneSignalCommonDefines.h in Headers */,
 				3CE8CC522911AE90000DB0D3 /* OSNetworkingUtils.h in Headers */,
 				DEBAAEB02A435B4D00BF2C1C /* OSLocation.h in Headers */,
+				3C5501402E09CF0100E77DF7 /* OSCopyOnWriteSet.h in Headers */,
 				DE971754274C48CF00FC409E /* OSPrivacyConsentController.h in Headers */,
 				3CE8CC4E2911ADD1000DB0D3 /* OSDeviceUtils.h in Headers */,
 				3C47A974292642B100312125 /* OneSignalConfigManager.h in Headers */,
@@ -4215,6 +4225,7 @@
 			files = (
 				3CC063A72B6D7A8E002BB07F /* OneSignalCoreTests.swift in Sources */,
 				3C24B0EC2BD09D7A0052E771 /* OneSignalCoreObjCTests.m in Sources */,
+				3C5501432E09F3D900E77DF7 /* LoggingTests.swift in Sources */,
 			);
 			runOnlyForDeploymentPostprocessing = 0;
 		};
@@ -4455,6 +4466,7 @@
 				DE7D182E270275FA002D3A5D /* OneSignalTrackFirebaseAnalytics.m in Sources */,
 				DE51DDE5294262AB0073D5C4 /* OSRemoteParamController.m in Sources */,
 				DE7D182827026F86002D3A5D /* OneSignalUserDefaults.m in Sources */,
+				3C5501412E09CF0100E77DF7 /* OSCopyOnWriteSet.m in Sources */,
 				3CC063942B6D6B6B002BB07F /* OneSignalCore.m in Sources */,
 			);
 			runOnlyForDeploymentPostprocessing = 0;

iOS_SDK/OneSignalSDK/OneSignalCore/Source/OSCopyOnWriteSet.h

@@ -0,0 +1,43 @@
+/**
+ * Modified MIT License
+ *
+ * Copyright 2025 OneSignal
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a copy
+ * of this software and associated documentation files (the "Software"), to deal
+ * in the Software without restriction, including without limitation the rights
+ * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+ * copies of the Software, and to permit persons to whom the Software is
+ * furnished to do so, subject to the following conditions:
+ *
+ * 1. The above copyright notice and this permission notice shall be included in
+ * all copies or substantial portions of the Software.
+ *
+ * 2. All copies of substantial portions of the Software may only be used in connection
+ * with services provided by OneSignal.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+ * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+ * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+ * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
+ * THE SOFTWARE.
+ */
+
+#import <Foundation/Foundation.h>
+
+/**
+ Usage of this class should be limited to cases where modification is rare but reads are frequent.
+ */
+@interface OSCopyOnWriteSet<__covariant ObjectType> : NSObject {
+    NSMutableSet *_set;
+    NSLock *_lock;
+}
+
+- (instancetype)init;
+- (void)addObject:(ObjectType)object;
+- (void)removeObject:(ObjectType)object;
+- (NSSet *)allObjects;
+
+@end

iOS_SDK/OneSignalSDK/OneSignalCore/Source/OSCopyOnWriteSet.m

@@ -0,0 +1,71 @@
+/**
+ * Modified MIT License
+ *
+ * Copyright 2025 OneSignal
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a copy
+ * of this software and associated documentation files (the "Software"), to deal
+ * in the Software without restriction, including without limitation the rights
+ * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+ * copies of the Software, and to permit persons to whom the Software is
+ * furnished to do so, subject to the following conditions:
+ *
+ * 1. The above copyright notice and this permission notice shall be included in
+ * all copies or substantial portions of the Software.
+ *
+ * 2. All copies of substantial portions of the Software may only be used in connection
+ * with services provided by OneSignal.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+ * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+ * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+ * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
+ * THE SOFTWARE.
+ */
+
+#import "OSCopyOnWriteSet.h"
+
+@implementation OSCopyOnWriteSet
+
+- (instancetype)init {
+    if (self = [super init]) {
+        _set = [[NSMutableSet alloc] init];
+        _lock = [[NSLock alloc] init];
+    }
+    return self;
+}
+
+- (void)addObject:(id)object {
+    [_lock lock];
+
+    // Create a new copy and modify it
+    NSMutableSet *newSet = [_set mutableCopy];
+    [newSet addObject:object];
+
+    // Update the internal set
+    _set = newSet;
+
+    [_lock unlock];
+}
+
+- (void)removeObject:(id)object {
+    [_lock lock];
+
+    // Create a new copy and modify it
+    NSMutableSet *newSet = [_set mutableCopy];
+    [newSet removeObject:object];
+
+    // Update the internal set
+    _set = newSet;
+
+    [_lock unlock];
+}
+
+- (NSSet *)allObjects {
+    // Read operation - no lock needed
+    return _set;
+}
+
+@end

iOS_SDK/OneSignalSDK/OneSignalCore/Source/OneSignalLog.h

@@ -36,9 +36,40 @@ typedef NS_ENUM(NSUInteger, ONE_S_LOG_LEVEL) {
     ONE_S_LL_VERBOSE
 };
 
+@interface OneSignalLogEvent : NSObject
+@property(readonly)ONE_S_LOG_LEVEL level;
+@property(readonly, nonnull)NSString *entry;
+@end
+
+@protocol OSLogListener <NSObject>
+- (void)onLogEvent:(OneSignalLogEvent *_Nonnull)event;
+@end
+
 @protocol OSDebug <NSObject>
+/**
+ The log level the OneSignal SDK should be writing to the Xcode log. Defaults to [LogLevel.WARN].
+
+ WARNING: This should not be set higher than LogLevel.WARN in a production setting.
+ */
 + (void)setLogLevel:(ONE_S_LOG_LEVEL)logLevel;
+/**
+ The log level the OneSignal SDK should be showing as a modal. Defaults to [LogLevel.NONE].
+
+ WARNING: This should not be used in a production setting.
+ */
 + (void)setAlertLevel:(ONE_S_LOG_LEVEL)logLevel NS_REFINED_FOR_SWIFT;
+/**
+ Add a listener to receive all logging messages the SDK produces.
+ Useful to capture and send logs to your server.
+
+ NOTE: All log messages are always passed, LogLevel has no effect on this.
+ */
++ (void)addLogListener:(NSObject<OSLogListener>*_Nonnull)listener NS_REFINED_FOR_SWIFT;
+/**
+ Removes a listener added by addLogListener
+ */
++ (void)removeLogListener:(NSObject<OSLogListener>*_Nonnull)listener NS_REFINED_FOR_SWIFT;
+
 @end
 
 @interface OneSignalLog : NSObject<OSDebug>

iOS_SDK/OneSignalSDK/OneSignalCore/Source/OneSignalLog.m

@@ -28,6 +28,15 @@
 #import <Foundation/Foundation.h>
 #import "OneSignalLog.h"
 #import "OSDialogInstanceManager.h"
+#import "OSCopyOnWriteSet.h"
+
+@implementation OneSignalLogEvent
+- (instancetype)initWithLevel:(ONE_S_LOG_LEVEL)level entry:(NSString*)entry {
+    _level = level;
+    _entry = entry;
+    return self;
+}
+@end
 
 @implementation OneSignalLog
 
@@ -38,6 +47,15 @@ @implementation OneSignalLog
     return self;
 }
 
++ (OSCopyOnWriteSet<NSObject<OSLogListener> *>*)logListeners {
+    static OSCopyOnWriteSet<NSObject<OSLogListener> *> *_logListeners;
+    static dispatch_once_t onceToken;
+    dispatch_once(&onceToken, ^{
+        _logListeners = [OSCopyOnWriteSet new];
+    });
+    return _logListeners;
+}
+
 + (void)setLogLevel:(ONE_S_LOG_LEVEL)nsLogLevel {
     _nsLogLevel = nsLogLevel;
 }
@@ -46,6 +64,14 @@ + (void)setAlertLevel:(ONE_S_LOG_LEVEL)logLevel {
     _alertLogLevel = logLevel;
 }
 
++ (void)addLogListener:(NSObject<OSLogListener>*_Nonnull)listener {
+    [self.logListeners addObject:listener];
+}
+
++ (void)removeLogListener:(NSObject<OSLogListener>*_Nonnull)listener {
+    [self.logListeners removeObject:listener];
+}
+
 + (void)onesignalLog:(ONE_S_LOG_LEVEL)logLevel message:(NSString* _Nonnull)message {
     onesignal_Log(logLevel, message);
 }
@@ -86,6 +112,13 @@ void onesignal_Log(ONE_S_LOG_LEVEL logLevel, NSString* message) {
     if (logLevel <= _alertLogLevel) {
         [[OSDialogInstanceManager sharedInstance] presentDialogWithTitle:levelString withMessage:message withActions:nil cancelTitle:NSLocalizedString(@"Close", @"Close button") withActionCompletion:nil];
     }
+
+    for (NSObject<OSLogListener> *listener in OneSignalLog.logListeners.allObjects) {
+        if ([listener respondsToSelector:@selector(onLogEvent:)]) {
+            OneSignalLogEvent *event = [[OneSignalLogEvent alloc] initWithLevel:logLevel entry:[levelString stringByAppendingString:message]];
+            [listener onLogEvent:event];
+        }
+    }
 }
 
 @end