The Validic Inform iOS Mobile SDK offers native mobile libraries which you can implement into your mobile project to power data syncing with the Apple Health data aggregation platform.

The Validic Inform iOS Mobile SDK supports Apple Health for native iOS. This document lays out the installation and use of the Apple Health integration.

Apple Health allows health and fitness apps to store and share the same on-device data, within a unified ecosystem. It also offers a single place for users to control which apps can read and write health and fitness data.

Apple Health combines data from a variety of other fitness and health apps, as well as the Apple Watches.

Installation

Apple Health has its own module in the Inform SDK, therefore the following modules are required to use the Apple Health integration:

Core (Session)
Apple Health

You can find more details on the installation process in Installation.

Session

A valid session is required in order to use the Apple Health integration in the Validic Inform SDK. See Session for more information.

Record types

The record types used in the Validic Inform Mobile SDK are described in Record Types.

Record Identifiers

More information on record identifiers can be found in Record Identifiers.

Listening for InformRecord Upload

More information on record events can be found in Record Events.

Apple Health

This project integrates Apple Health with the Validic Mobile Inform SDK to passively collect data on behalf of an end user. Validic ensures that our Mobile SDK makes use of the minimal scopes needed for our supported data types.

Subscribe to new health data

Subscribing to HealthKit data only needs to be done once for a user session. The subscriptions will be persisted across app launches in the VLDSession object. A typical use of the Validic HealthKit framework would be to create a UISwitch that adds the required subscriptions when turned on and removes them when turned off. Example:

func toggleHealthKit(_ sender: UISwitch) {
    if sender.isOn {
        // To subscribe to specific sample types (e.g. steps, body mass, and sleep analysis):
        let sampleTypes = [HKQuantityType(.stepCount), HKQuantityType(.bodyMass), HKCategoryType(.sleepAnalysis)]
        // OR, to subscribe to all supported sample types (not recommended):
        let sampleTypes = VLDHealthKitSubscription.supportedObjectTypes() as! Set<HKSampleType>

        VLDHealthKitManager.sharedInstance().setSubscriptions(Array(sampleTypes), completion: nil)
    }
    else {
        VLDHealthKitManager.sharedInstance().setSubscriptions([], completion: nil)
    }
}

Retrieve data continuously

To properly enable the continuous delivery of data in the background and foreground, the subscription observers need to be recreated immediately when the app is launched from a suspended or terminated state. To do this, you need to call [VLDHealthKitManager -observeCurrentSubscriptions] inside your application delegate's application:didFinishLaunchingWithOptions: function. For example:

func application(_ application: UIApplication didFinishLaunchingWithOptions launchOptions: [UIApplicationLaunchOptionsKey : Any]? = nil) -> Bool {
    VLDHealthKitManager.sharedInstance().observeCurrentSubscriptions()
    return true
}

Note: Calling [[VLDSession] sharedInstance] endSession] in Objective-C or VLDSession.sharedInstance().end() in Swift will remove all HealthKit subscriptions and stop listening for new data.

Please note, there are some special considerations that you need to be aware of when working with Apple Health.

Fetch historical data

The ValidicHealthKit framework provides the ability to query up to 180 days of historical data for a subset of data types provided by HealthKit by using one of more values of the VLDHealthKitHistoricalSet enum.

Three historical sets are available:

VLDHealthKitHistoricalSetSummary - Step data
VLDHealthKitHistoricalSetWorkout - Workout data

To fetch historical HealthKit data, call the fetchHistoricalSets: method on VLDHealthKitManager and pass in the historical sets you want to fetch, along with from and to parameters.

The from and to parameters should be DateComponents with the year, month, and day components defined. Data is always pulled in full-day increments, so any time data on the DateComponents (hour, minute, second, etc) will be ignored. Historical data cannot go back more than 179 days before the current day.

Example pulling 30 days of history:

The ValidicHealthKit framework provides the ability to query up to 180 days of historical data for a subset of data types provided by HealthKit by using one of more values of the VLDHealthKitHistoricalSet enum.

Three historical sets are available:

VLDHealthKitHistoricalSetSummary - Step data
VLDHealthKitHistoricalSetWorkout - Workout data
VLDHealthKitHistoricalSetIntraday - Intraday step data (Premium feature, with access to only 7 days of historical data)
To fetch historical HealthKit data, call the fetchHistoricalSets: method on VLDHealthKitManager and pass in the historical sets you want to fetch, along with from and to parameters.

The from and to parameters should be DateComponents with the year, month, and day components defined. Data is always pulled in full-day increments, so any time data on the DateComponents (hour, minute, second, etc) will be ignored. Historical data cannot go back more than 179 days before the current day.

Example pulling 30 days of history:

Doing this may display a permission dialog from HealthKit, so it's important to call this at an appropriate time in your app. It is recommended to explain to the user why you want this data before attempting to fetch it. This operation may take several seconds to complete, so it is advisable to display an activity indicator to the user until the completion block is called.

When the fetch completes, all the data has been fetched locally and queued up for submission to the server.

The amount of time needed to upload the records may vary based on the amount of history fetched and the user's internet speed. The queued records are uploaded automatically by the library based on connectivity, but it is possible for the user to suspend the app before all the records have been uploaded. The remaining records will be uploaded when the user resumes the app. This should be kept in mind when receiving records from the Validic server.