I have created a session in Watch and updating Heart Rate Data in Health Kit. Now, I want to Display the current Heart Rate in my iPhone Screen. Watch sensor update the Heart Rate Data in Health kit BUT iPhone Application in NOT able to Fetch Real-Time Data from the Health kit. I have tested out below TWO scenarios. I have also recalled this method/function using timer BUT it is not getting real-time data.
Note: When I open Health App and Re-open my application then It will automatically refresh the data. If my application continuously in foreground then below code not refreshing latest data from the health kit
1. Tried to get Real Time Heart Rate Data using HKSampleQuery
let calendar = NSCalendar.current
let components = calendar.dateComponents([.year, .month, .day], from: Date())
let startDate : NSDate = calendar.date(from: components)! as NSDate
let endDate : Date = calendar.date(byAdding: Calendar.Component.day, value: 1, to: startDate as Date)!
let predicate = HKQuery.predicateForSamples(withStart: startDate as Date, end: endDate, options:[])
//descriptor
let sortDescriptors = [NSSortDescriptor(key: HKSampleSortIdentifierEndDate, ascending: false)]
self.heartRateQuery = HKSampleQuery(sampleType: self.heartRateType, predicate: predicate, limit: 1, sortDescriptors: sortDescriptors, resultsHandler: { (query:HKSampleQuery, results:[HKSample]?, error:Error?) in
guard error == nil else { print("error in getting data"); return }
self.collectCurrentHeartRateSample(currentSampleTyple: results)
})
self.healthStore.execute(self.heartRateQuery!)
2. Tried to get Real Time Heart Rate Data using HKAnchoredObjectQuery
let sampleType : HKSampleType = HKObjectType.quantityType(forIdentifier: HKQuantityTypeIdentifier.heartRate)!
let predicate : NSPredicate = HKQuery.predicateForSamples(withStart: startDate as Date, end: endDate, options: [])
let anchor: HKQueryAnchor = HKQueryAnchor(fromValue: 0)
let anchoredQuery = HKAnchoredObjectQuery(type: sampleType, predicate: predicate, anchor: anchor, limit: HKObjectQueryNoLimit) { (query, samples, deletedObjects, anchor, error ) in
self.collectCurrentHeartRateSample(currentSampleTyple: samples!, deleted: deletedObjects!)
}
anchoredQuery.updateHandler = { (query, samples, deletedObjects, anchor, error) -> Void in
self.collectCurrentHeartRateSample(currentSampleTyple: samples!, deleted: deletedObjects!)
}
self.healthStore.execute(anchoredQuery)
=============================================
Parsed the Data
func collectCurrentHeartRateSample(currentSampleTyple : [HKSample]?, deleted :
[HKDeletedObject]?){
// func collectCurrentHeartRateSample(currentSampleTyple : [HKSample]?){
DispatchQueue.main.async {
self.currentHeartRateSample = currentSampleTyple
//Get Last Sample of Heart Rate
self.currentHeartLastSample = self.currentHeartRateSample?.last
print("lastSample : \(String(describing: self.currentHeartLastSample))")
if self.currentHeartLastSample != nil {
let result = self.currentHeartLastSample as! HKQuantitySample
let heartRateBPM = result.quantity.doubleValue(for: HKUnit(from: "count/min"))
let heartRateBPMUnit = "count/min"
let deviceUUID = self.currentHeartLastSample?.uuid
let deviceIdentity = result.sourceRevision.source.name
let deviceProductName = self.currentHeartLastSample?.device?.name
let deviceProductType = result.sourceRevision.productType
let deviceOSVersion = result.sourceRevision.version
let startDate = self.currentHeartLastSample?.startDate
let endDate = self.currentHeartLastSample?.endDate
self.aCollectionView.reloadData()
}
}
}
Here is my own analysis regarding get nearby real-time Heart Rate.
1. If you are accessing Health Kit data using iPhone app, In this scenario, Health Kit DB NOT frequently updated/refreshed. So, your app not able to get real-time latest updated data through iPhone app.
2. Using a watch app, you can access near real-time data through Health Kit DB. Watch app is able to get the real-time latest updated Health Kit Data.
3. You need to transfer data from watch to iPhone app. Here is a code for your reference. You can write code as per your requirement. You just need to access Heart Rate through HKQuery
let defaultSession = WCSession.default
let healthStore = HKHealthStore()
var currentHeartRateSample : [HKSample]?
var currentHeartLastSample : HKSample?
var currentHeartRateBPM = Double()
//Get Heart Rate from Health Kit
func getCurrentHeartRateData(){
let calendar = Calendar.current
let components = calendar.dateComponents([.year, .month, .day], from: Date())
let startDate : Date = calendar.date(from: components)!
let endDate : Date = calendar.date(byAdding: Calendar.Component.day, value: 1, to: startDate as Date)!
let sampleType : HKSampleType = HKObjectType.quantityType(forIdentifier: HKQuantityTypeIdentifier.heartRate)!
let predicate : NSPredicate = HKQuery.predicateForSamples(withStart: startDate, end: endDate, options: [])
let anchor: HKQueryAnchor = HKQueryAnchor(fromValue: 0)
let anchoredQuery = HKAnchoredObjectQuery(type: sampleType, predicate: predicate, anchor: anchor, limit: HKObjectQueryNoLimit) { (query, samples, deletedObjects, anchor, error ) in
if samples != nil {
self.collectCurrentHeartRateSample(currentSampleTyple: samples!, deleted: deletedObjects!)
}
}
anchoredQuery.updateHandler = { (query, samples, deletedObjects, anchor, error) -> Void in
self.collectCurrentHeartRateSample(currentSampleTyple: samples!, deleted: deletedObjects!)
}
self.healthStore.execute(anchoredQuery)
}
//Retrived necessary parameter from HK Sample
func collectCurrentHeartRateSample(currentSampleTyple : [HKSample]?, deleted : [HKDeletedObject]?){
self.currentHeartRateSample = currentSampleTyple
//Get Last Sample of Heart Rate
self.currentHeartLastSample = self.currentHeartRateSample?.last
if self.currentHeartLastSample != nil {
let lastHeartRateSample = self.currentHeartLastSample as! HKQuantitySample
self.currentHeartRateBPM = lastHeartRateSample.quantity.doubleValue(for: HKUnit(from: "count/min"))
let heartRateStartDate = lastHeartRateSample.startDate
let heartRateEndDate = lastHeartRateSample.endDate
//Send Heart Rate Data Using Send Messge
DispatchQueue.main.async {
let message = [
"HeartRateBPM" : "\(self.currentHeartRateBPM)",
"HeartRateStartDate" : "\(heartRateStartDate)",
"HeartRateEndDate" : "\(heartRateEndDate)"
]
//Transfer data from watch to iPhone
self.defaultSession.sendMessage(message, replyHandler:nil, errorHandler: { (error) in
print("Error in send message : \(error)")
})
}
}
}