implemented fitness_initializeStepEventObserver and exported RCT initStepCountObserver method

RCTAppleHealthKit/RCTAppleHealthKit+Methods_Fitness.h

@@ -18,6 +18,8 @@
 
 - (void)fitness_saveSteps:(NSDictionary *)input callback:(RCTResponseSenderBlock)callback;
 
+- (void)fitness_initializeStepEventObserver:(NSDictionary *)input callback:(RCTResponseSenderBlock)callback;
+
 - (void)fitness_getDistanceWalkingRunningOnDay:(NSDictionary *)input callback:(RCTResponseSenderBlock)callback;
 - (void)fitness_getDistanceCyclingOnDay:(NSDictionary *)input callback:(RCTResponseSenderBlock)callback;
 - (void)fitness_getFlightsClimbedOnDay:(NSDictionary *)input callback:(RCTResponseSenderBlock)callback;

RCTAppleHealthKit/RCTAppleHealthKit+Methods_Fitness.m

@@ -10,8 +10,12 @@
 #import "RCTAppleHealthKit+Queries.h"
 #import "RCTAppleHealthKit+Utils.h"
 
+#import "RCTBridge.h"
+#import "RCTEventDispatcher.h"
+
 @implementation RCTAppleHealthKit (Methods_Fitness)
 
+
 //- (void)fitness_getStepCountForToday:(NSDictionary *)input callback:(RCTResponseSenderBlock)callback
 //{
 //    HKQuantityType *stepCountType = [HKObjectType quantityTypeForIdentifier:HKQuantityTypeIdentifierStepCount];
@@ -156,6 +160,38 @@
 
 
 
+- (void)fitness_initializeStepEventObserver:(NSDictionary *)input callback:(RCTResponseSenderBlock)callback
+{
+    HKSampleType *sampleType =
+    [HKObjectType quantityTypeForIdentifier:HKQuantityTypeIdentifierStepCount];
+
+    HKObserverQuery *query =
+    [[HKObserverQuery alloc]
+     initWithSampleType:sampleType
+     predicate:nil
+     updateHandler:^(HKObserverQuery *query,
+                     HKObserverQueryCompletionHandler completionHandler,
+                     NSError *error) {
+
+         if (error) {
+             // Perform Proper Error Handling Here...
+             NSLog(@"*** An error occured while setting up the stepCount observer. %@ ***", error.localizedDescription);
+             callback(@[RCTMakeError(@"An error occured while setting up the stepCount observer", error, nil)]);
+             return;
+         }
+
+          [self.bridge.eventDispatcher sendAppEventWithName:@"change:steps"
+                                                       body:@{@"name": @"change:steps"}];
+
+         // If you have subscribed for background updates you must call the completion handler here.
+         // completionHandler();
+
+     }];
+
+    [self.healthStore executeQuery:query];
+}
+
+
 
 - (void)fitness_getDistanceWalkingRunningOnDay:(NSDictionary *)input callback:(RCTResponseSenderBlock)callback
 {

RCTAppleHealthKit/RCTAppleHealthKit.m

@@ -17,8 +17,14 @@
 #import "RCTAppleHealthKit+Methods_Vitals.h"
 #import "RCTAppleHealthKit+Methods_Results.h"
 
+#import "RCTBridge.h"
+#import "RCTEventDispatcher.h"
+
 @implementation RCTAppleHealthKit
 
+@synthesize bridge = _bridge;
+
+
 RCT_EXPORT_MODULE();
 
 
@@ -32,6 +38,11 @@ RCT_EXPORT_METHOD(initHealthKit:(NSDictionary *)input callback:(RCTResponseSende
     [self initializeHealthKit:input callback:callback];
 }
 
+RCT_EXPORT_METHOD(initStepCountObserver:(NSDictionary *)input callback:(RCTResponseSenderBlock)callback)
+{
+    [self fitness_initializeStepEventObserver:input callback:callback];
+}
+
 RCT_EXPORT_METHOD(getBiologicalSex:(NSDictionary *)input callback:(RCTResponseSenderBlock)callback)
 {
     [self characteristic_getBiologicalSex:input callback:callback];