Backport defaultSettings feature from 4.x to 3.x.

Analytics/Classes/Integrations/SEGIntegrationsManager.m

@@ -423,6 +423,12 @@ - (void)refreshSettings
                     NSDictionary *previouslyCachedSettings = [self cachedSettings];
                     if (previouslyCachedSettings && [previouslyCachedSettings count] > 0) {
                         [self setCachedSettings:previouslyCachedSettings];
+                    } else if (self.configuration.defaultSettings != nil) {
+                        // If settings request fail, load a user-supplied version if present.
+                        // but make sure segment.io is in the integrations
+                        NSMutableDictionary *newSettings = [self.configuration.defaultSettings serializableMutableDeepCopy];
+                        newSettings[@"integrations"][@"Segment.io"][@"apiKey"] = self.configuration.writeKey;
+                        [self setCachedSettings:newSettings];
                     } else {
                         // If settings request fail, fall back to using just Segment integration.
                         // Doesn't address situations where this callback never gets called (though we don't expect that to ever happen).

Analytics/Classes/Internal/SEGAnalyticsUtils.h

@@ -36,6 +36,7 @@ NSString *SEGEventNameForScreenTitle(NSString *title);
 
 // Deep copy and check NSCoding conformance
 @protocol SEGSerializableDeepCopy <NSObject>
+-(id _Nullable) serializableMutableDeepCopy;
 -(id _Nullable) serializableDeepCopy;
 @end
 

Analytics/Classes/Internal/SEGAnalyticsUtils.m

@@ -244,9 +244,9 @@ static id SEGCoerceJSONObject(id obj)
 
 @implementation NSDictionary(SerializableDeepCopy)
 
-- (NSDictionary *)serializableDeepCopy
+- (id)serializableDeepCopy:(BOOL)mutable
 {
-    NSMutableDictionary *returnDict = [[NSMutableDictionary alloc] initWithCapacity:self.count];
+    NSMutableDictionary *result = [[NSMutableDictionary alloc] initWithCapacity:self.count];
     NSArray *keys = [self allKeys];
     for (id key in keys) {
         id aValue = [self objectForKey:key];
@@ -263,27 +263,39 @@ - (NSDictionary *)serializableDeepCopy
         }
 
         if ([aValue conformsToProtocol:@protocol(SEGSerializableDeepCopy)]) {
-            theCopy = [aValue serializableDeepCopy];
+            theCopy = [aValue serializableDeepCopy:mutable];
         } else if ([aValue conformsToProtocol:@protocol(NSCopying)]) {
             theCopy = [aValue copy];
         } else {
             theCopy = aValue;
         }
 
-        [returnDict setValue:theCopy forKey:key];
-  }
+        [result setValue:theCopy forKey:key];
+    }
 
-  return [returnDict copy];
+    if (mutable) {
+        return result;
+    } else {
+        return [result copy];
+    }
+}
+
+- (NSDictionary *)serializableDeepCopy {
+    return [self serializableDeepCopy:NO];
+}
+
+- (NSMutableDictionary *)serializableMutableDeepCopy {
+    return [self serializableDeepCopy:YES];
 }
 
 @end
 
 
 @implementation NSArray(SerializableDeepCopy)
 
--(NSArray *)serializableDeepCopy
+-(id)serializableDeepCopy:(BOOL)mutable
 {
-    NSMutableArray *returnArray = [[NSMutableArray alloc] initWithCapacity:self.count];
+    NSMutableArray *result = [[NSMutableArray alloc] initWithCapacity:self.count];
 
     for (id aValue in self) {
         id theCopy = nil;
@@ -299,16 +311,30 @@ -(NSArray *)serializableDeepCopy
         }
 
         if ([aValue conformsToProtocol:@protocol(SEGSerializableDeepCopy)]) {
-            theCopy = [aValue serializableDeepCopy];
+            theCopy = [aValue serializableDeepCopy:mutable];
         } else if ([aValue conformsToProtocol:@protocol(NSCopying)]) {
             theCopy = [aValue copy];
         } else {
             theCopy = aValue;
         }
-        [returnArray addObject:theCopy];
+        [result addObject:theCopy];
     }
 
-    return [returnArray copy];
+    if (mutable) {
+        return result;
+    } else {
+        return [result copy];
+    }
+}
+
+
+- (NSArray *)serializableDeepCopy {
+    return [self serializableDeepCopy:NO];
 }
 
+- (NSMutableArray *)serializableMutableDeepCopy {
+    return [self serializableDeepCopy:YES];
+}
+
+
 @end

Analytics/Classes/SEGAnalyticsConfiguration.h

@@ -127,6 +127,13 @@ typedef NSMutableURLRequest *_Nonnull (^SEGRequestFactory)(NSURL *_Nonnull);
  */
 @property (nonatomic, strong, nullable) id<SEGCrypto> crypto;
 
+
+/**
+ * Set the default settings to use if Segment.com cannot be reached. 
+ * An example configuration can be found here, using your write key:  https://cdn-settings.segment.com/v1/projects/YOUR_WRITE_KEY/settings
+ */
+@property (nonatomic, strong, nullable) NSDictionary *defaultSettings;
+
 /**
  * Set custom middlewares. Will be run before all integrations
  */