Query HealthKit for HKCategoryTypeIdentifierSleepAnalysis

Question

I have built a method that imports a sleep sample but I can't get it to return the proper value for hours asleep.

The method to query for sleep data looks like this:

func updateHealthCategories() {

    let categoryType = HKObjectType.categoryTypeForIdentifier(HKCategoryTypeIdentifierSleepAnalysis)

    let start = NSDate(dateString:"2015-11-04")
    let end = NSDate(dateString:"2015-11-05")

    let categorySample = HKCategorySample(type: categoryType!,
        value: HKCategoryValueSleepAnalysis.Asleep.rawValue,
        startDate: start,
        endDate: end)

    self.hoursSleep = Double(categorySample.value)

    print(categorySample.value)
}

The date is formatted like this:

extension NSDate
{
    convenience
    init(dateString:String) {
        let dateStringFormatter = NSDateFormatter()
        dateStringFormatter.dateFormat = "yyyy-MM-dd"
        dateStringFormatter.locale = NSLocale(localeIdentifier: "en_US_POSIX")
        let d = dateStringFormatter.dateFromString(dateString)!
        self.init(timeInterval:0, sinceDate:d)
    }
}

I'm calling data from November 4-5, which contains this data:

However, the categorySample.value returns 1 instead of 3.

Answer 1

The value you are accessing is the category sample value, an HKCategoryType, and not the number of hours of sleep.

The definition for HKCategoryTypeIdentifierSleepAnalysis

typedef enum : NSInteger {
   HKCategoryValueSleepAnalysisInBed,
   HKCategoryValueSleepAnalysisAsleep,
} HKCategoryValueSleepAnalysis;

defines two possible values, 0 or 1 where the value of 1 matches HKCategoryValueSleepAnalysisAsleep.

Getting the hours asleep requires setting up a HKSampleQuery.

The code looks something like this:

if let sleepType = HKObjectType.categoryTypeForIdentifier(HKCategoryTypeIdentifierSleepAnalysis) {

    let predicate = HKQuery.predicateForSamplesWithStartDate(startDate, endDate: endDate, options: .None)
    let sortDescriptor = NSSortDescriptor(key: HKSampleSortIdentifierEndDate, ascending: false)
    let query = HKSampleQuery(sampleType: sleepType, predicate: predicate, limit: 30, sortDescriptors: [sortDescriptor]) { (query, tmpResult, error) -> Void in                  
        if let result = tmpResult {
            for item in result {
                if let sample = item as? HKCategorySample {                     
                    let value = (sample.value == HKCategoryValueSleepAnalysis.InBed.rawValue) ? "InBed" : "Asleep"                     
                    print("sleep: \(sample.startDate) \(sample.endDate) - source: \(sample.source.name) - value: \(value)")
                    let seconds = sample.endDate.timeIntervalSinceDate(sample.startDate)
                    let minutes = seconds/60
                    let hours = minutes/60
                }
            }
        }
    }

    healthStore.executeQuery(query)
}

I summarized this from http://benoitpasquier.fr/sleep-healthkit/.

Answer 2

Here is Swift 5, iOS 16 compatible answer if someone is still looking. You can parse/operate data as per your needs.

func getSleepAnalysis() {
    let healthStore = HKHealthStore()
    let endDate = Date()

    guard let startDate = Calendar.current.date(byAdding: .day, value: -7, to: endDate) else {
        fatalError("*** Unable to create the start date ***")
    }


    // first, we define the object type we want
    guard let sleepType = HKObjectType.categoryType(forIdentifier: .sleepAnalysis) else {
        return
    }

    // we create a predicate to filter our data
    let predicate = HKQuery.predicateForSamples(withStart: startDate, end: endDate, options: .strictStartDate)

    // I had a sortDescriptor to get the recent data first
    let sortDescriptor = NSSortDescriptor(key: HKSampleSortIdentifierEndDate, ascending: false)

    // we create our query with a block completion to execute
    let query = HKSampleQuery(sampleType: sleepType, predicate: predicate, limit: Int(HKObjectQueryNoLimit), sortDescriptors: [sortDescriptor]) { (query, result, error) in
        if error != nil {
            // handle error
            return
        }

        if let result = result {

            // do something with those data
            result
                .compactMap({ $0 as? HKCategorySample })
                .forEach({ sample in
                    guard let sleepValue = HKCategoryValueSleepAnalysis(rawValue: sample.value) else {
                        return
                    }

                    let isAsleep = sleepValue == .asleep
                    print("HealthKit sleep \(sample.startDate) \(sample.endDate) - source \(sample.sourceRevision.source.name) - isAsleep \(isAsleep)")
                })
        }
    }

    // finally, we execute our query
    healthStore.execute(query)
}

I hope you'll get the authorization for SleepAnalysis before this so data is retrived.