Create new HKQuantityType

Question

I've read in some pages that you can add custom samples to HealthKit in order to have another measurements saved.

In my case, I want to add accelerometer data from the apple watch to HealthKit.

This is my code

func saveSample(data:Double, date:NSDate ) {
    let dataType = HKQuantityType.quantityType(forIdentifier: HKQuantityTypeIdentifier.init(rawValue: "acc"))
    let dataQuantity = HKQuantity(unit: HKUnit.init(from: "m/s^2"), doubleValue: data)
    let dataSample = HKQuantitySample(type: dataType!, quantity: dataQuantity, start: date as Date, end: date as Date)
    healthKitStore.save(dataSample, withCompletion: { (success, error) -> Void in
        if( error != nil ) {
            print("Error saving sample:")
        } else {
            print("Sample saved successfully!")
        }
    })
}

I want to add a sample called "acc" (in a normal case one example of this could be "bloodPreasure") with unit "m/s^2".

I get nil on dataType, so then I get this Error on let dataSample = HKQuantitySample(type: dataType!, quantity: dataQuantity, start: date as Date, end: date as Date) line, because dataType is nil.

fatal error: unexpectedly found nil while unwrapping an Optional value

Any ideas,How to implement this? Thank u all!

Answer 1

I believe for HKQuantityType.quantityType(forIdentifier: we need to provide identifier provided by apple like HKQuantityTypeIdentifier.bodyTemperature. And then only it will return an object of quantityType.

So you are getting nil in dataType.

And I believe we can't create new HKQuantityType because health store will have to save it too, and that part is not in our control.