HealthKit Permission Behavior# PRO

When using the Health module provided by the Scripting app to access iOS HealthKit data, it's important to understand how HealthKit handles authorization and how Scripting adapts to these behaviors. This document explains the authorization flow, Promise behavior, and best practices for handling missing permissions.

#Key Characteristics of iOS HealthKit Authorization

1. No public API to check authorization status iOS does not provide any public API to determine whether a specific HealthKit data type has been authorized or denied. Apps cannot check this directly.

2. Authorization prompt appears only once per type The system will show a permission dialog only if the data type's status is notDetermined. Once the user grants or denies access, the dialog will not reappear.

3. No system-level error if access is denied If an app attempts to access unauthorized data, HealthKit will not throw a system error. Instead, some APIs return empty results, while others may reject the Promise.

#Scripting App Behavior

#Automatic Authorization Request

When you call any Health API that requires access to protected data, the Scripting app will automatically trigger the system permission dialog if any of the required types are not yet determined.

For example:

await Health.dateOfBirth()
await Health.bloodType()
await Health.queryQuantitySamples('stepCount')

#Promise Behavior by API

#Code Examples

#Example 1: Querying samples (returns empty array when unauthorized)

const steps = await Health.queryQuantitySamples('stepCount')

if (steps.length === 0) {
  console.log("No step data returned. This may be due to lack of permission or no recorded data.")
}

#Example 2: Reading profile information (rejects if unauthorized)

try {
  const dob = await Health.dateOfBirth()
  console.log(`Date of birth: ${dob.year}-${dob.month}-${dob.day}`)
} catch (err) {
  console.warn("Failed to read date of birth. The user may not have granted permission.")
}

#Permission Merging on Multiple Calls

If you call multiple permission-requiring methods simultaneously using Promise.all, Scripting will automatically merge the required permissions into a single system dialog request. This improves user experience by avoiding repeated prompts.

try {
  const [dob, blood] = await Promise.all([
    Health.dateOfBirth(),
    Health.bloodType()
  ])
  console.log(dob, blood)
} catch (err) {
  console.warn("User may have denied one or more requested permissions.")
}

#Best Practices and UI Recommendations

#Manual Authorization

Go to Health app > Data Access & Devices > Scripting, and make sure the necessary data types are enabled.