GetEnabledFeatures API added (#218)

* GetEnabledFeatures API added

* Copyright year corrected.

* indent correction.

Author: arafay-folio3

OptimizelySDKCore/OptimizelySDKCore/Optimizely.h

@@ -183,6 +183,15 @@ extern NSString * _Nonnull const OptimizelyNotificationsUserDictionaryExperiment
                                 userId:(nullable NSString *)userId
                             attributes:(nullable NSDictionary<NSString *, NSString *> *)attributes;
 
+/**
+ * Get the list of features that are enabled for the user.
+ * @param userId The user ID to be used for bucketing.
+ * @param attributes The user's attributes.
+ * @return NSArray<NSString> List of the feature keys that are enabled for the user.
+ */
+- (NSArray<NSString *> *_Nonnull)getEnabledFeatures:(nullable NSString *)userId
+                                         attributes:(nullable NSDictionary<NSString *, NSString *> *)attributes;
+
 #pragma mark - trackEvent methods
 /**
  * Track an event

OptimizelySDKCore/OptimizelySDKCore/Optimizely.m

@@ -353,6 +353,19 @@ - (NSString *)getFeatureVariableString:(nullable NSString *)featureKey
                                          userId:userId
                                      attributes:attributes];
 }
+    
+-(NSArray<NSString *> *)getEnabledFeatures:(NSString *)userId
+                                attributes:(NSDictionary<NSString *,NSString *> *)attributes {
+    
+    NSMutableArray<NSString *> *enabledFeatures = [NSMutableArray new];
+    for (OPTLYFeatureFlag *feature in self.config.featureFlags) {
+        NSString *featureKey = feature.key;
+        if ([self isFeatureEnabled:featureKey userId:userId attributes:attributes]) {
+            [enabledFeatures addObject:featureKey];
+        }
+    }
+    return enabledFeatures;
+}
 
 #pragma mark trackEvent methods
 - (void)track:(NSString *)eventKey userId:(NSString *)userId

OptimizelySDKCore/OptimizelySDKCoreTests/OptimizelyTest.m

@@ -1,5 +1,5 @@
 /****************************************************************************
- * Copyright 2016-2017, Optimizely, Inc. and contributors                   *
+ * Copyright 2016-2018, Optimizely, Inc. and contributors                   *
  *                                                                          *
  * Licensed under the Apache License, Version 2.0 (the "License");          *
  * you may not use this file except in compliance with the License.         *
@@ -928,6 +928,24 @@ - (void)testGetFeatureVariableValueForTypeWithRolloutRule {
    OCMVerify([decisionServiceMock getVariationForFeature:featureFlag userId:kUserId attributes:nil]);
    [decisionServiceMock stopMocking];
 }
+    
+#pragma mark - GetEnabledFeatures Tests
+
+// should return empty feature array as no feature is enabled for user
+-(void)testGetEnabledFeaturesWithNoFeatureEnabledForUser {
+    id optimizelyMock = OCMPartialMock(self.optimizely);
+    OCMStub([optimizelyMock isFeatureEnabled:[OCMArg any] userId:kUserId attributes:self.attributes]).andReturn(false);
+    XCTAssertEqual([optimizelyMock getEnabledFeatures:kUserId attributes:self.attributes].count, 0);
+    OCMVerify([optimizelyMock isFeatureEnabled:[OCMArg any] userId:kUserId attributes:self.attributes]);
+    [optimizelyMock stopMocking];
+}
+    
+// should return empty feature array as no feature is enabled for user
+-(void)testGetEnabledFeaturesWithSomeFeaturesEnabledForUser {
+    NSArray<NSString *> *enabledFeatures = @[@"booleanFeature", @"booleanSingleVariableFeature", @"multiVariateFeature"];
+    NSArray<NSString *> *features = [self.optimizely getEnabledFeatures:kUserId attributes:self.attributes];
+    XCTAssertEqualObjects(features, enabledFeatures);
+}
 
 #pragma mark - Helper Methods
 

OptimizelySDKShared/OptimizelySDKShared/OPTLYClient.m

@@ -1,5 +1,5 @@
 /****************************************************************************
- * Copyright 2016, Optimizely, Inc. and contributors                        *
+ * Copyright 2016, 2018, Optimizely, Inc. and contributors                  *
  *                                                                          *
  * Licensed under the Apache License, Version 2.0 (the "License");          *
  * you may not use this file except in compliance with the License.         *
@@ -197,6 +197,19 @@ - (int)getFeatureVariableInteger:(nullable NSString *)featureKey
                                                attributes:attributes];
     }
 }
+    
+- (NSArray<NSString *> *)getEnabledFeatures:(nullable NSString *)userId
+               attributes:(nullable NSDictionary<NSString *,NSString *> *)attributes {
+    if (self.optimizely == nil) {
+        [self.logger logMessage:OPTLYLoggerMessagesClientDummyOptimizelyError
+                      withLevel:OptimizelyLogLevelError];
+        return [NSArray new];
+    }
+    else {
+        return [self.optimizely getEnabledFeatures:userId
+                                        attributes:attributes];
+    }
+}
 
 
 - (NSString * _Nullable)getFeatureVariableString:(nullable NSString *)featureKey