Health 3.4.3 - iOS error when writing BMI value - could not cast value of type 'HKQuantitytype' - possible solution included

Device / Emulator and OS

Iphone 7 Plus (physical device)
OS: [iOS 15.3.1]

Describe the bug

Heads up: I've found the problem and included a proposal for the solution under: Additional information / possible solution

I attempt to write the BMI data as follows:

double _bmiResult = 22.9;
success = await health.writeHealthData(
            _bmiResult, HealthDataType.BODY_MASS_INDEX, earlier, now);

After calling writeHealthData the app crashes with this error : _Successfully called writeData with value of 22.9 and type of BODY_MASSINDEX

_Could not cast value of type 'HKQuantityType' (0x1e9536f68) to 'HKCategoryType' (0x1e9536f90). Could not cast value of type 'HKQuantityType' (0x1e9536f68) to 'HKCategoryType' (0x1e9536f90).

thread #1, queue = 'com.apple.main-thread', stop reason = signal SIGABRT frame #0: 0x00000001bbb6284c libsystem_kernel.dylib__pthread_kill + 8 libsystem_kernel.dylib__pthread_kill: -> 0x1bbb6284c <+8>: b.lo 0x1bbb62868 ; <+36> 0x1bbb62850 <+12>: stp x29, x30, [sp, #-0x10]! 0x1bbb62854 <+16>: mov x29, sp 0x1bbb62858 <+20>: bl 0x1bbb3ff5c ; cerrornocancel Target 0: (Runner) stopped. Lost connection to device.

To Reproduce

use the example app provided with Health 3.4.3
Add this function:

Future addDataBmiExample() async {
    final now = DateTime.now();
    final earlier = now.subtract(Duration(minutes: 5));

    final types = [HealthDataType.BODY_MASS_INDEX];
    final rights = [HealthDataAccess.WRITE];
    final permissions = [HealthDataAccess.READ_WRITE];
    bool? hasPermissions =
    await HealthFactory.hasPermissions(types, permissions: rights);
    if (hasPermissions == false) {
      await health.requestAuthorization(types, permissions: permissions);
    }

      bool success = await health.writeHealthData(
           _bmiResult, HealthDataType.BODY_MASS_INDEX, earlier, now);

      setState(() {
        _state = success ? AppState.DATA_ADDED : AppState.DATA_NOT_ADDED;
      });
  }

replace the onPressed() function

IconButton(
            onPressed: () {
              //addData();
              addDataBmiExample();
            },
            icon: Icon(Icons.add),
          ),

Expected behavior

I expect that the BMI data saved is correctly and most of all that the app does not crash :)

Actual behavior

The app crashes and the BMI data is not saved.

Screenshots

not available

Flutter doctor

[✓] Flutter (Channel stable, 2.8.1, on macOS 12.1 21C52 darwin-x64, locale en-NL) [✓] Android toolchain - develop for Android devices (Android SDK version 31.0.0) [✓] Xcode - develop for iOS and macOS (Xcode 13.2.1) [✓] Chrome - develop for the web [✓] Android Studio (version 2020.3) [✓] VS Code (version 1.63.2) [✓] Connected device (3 available) • No issues found!

Additional information / possible solution

I've done some searching to track down the problem. The problem is caused by the SwiftHealthPlugin.swift location: health-3.4.3/ios/Classes/SwithHealthPlugin.swift

I suspect the problem is caused by an invalid cast caused by these pieces of code: line 194˜196:

if (unitLookUp(key: type) == HKUnit.init(from: "")) {
          sample = HKCategorySample(type: dataTypeLookUp(key: type) as! HKCategoryType, value: Int(value), start: dateFrom, end: dateTo)
        }

and line 369: unitDict[BODY_MASS_INDEX] = HKUnit.init(from: "")

The problem is caused by the handling of (""). I used this as reference: https://developer.apple.com/documentation/healthkit/hkunit/1615733-init

and changed it to: unitDict[BODY_MASS_INDEX] = HKUnit.init(from: "count")

With that adjustment the BMI data is written successful and the app does not crash anymore.

Please note that the same issue also applies to:

       unitDict[MINDFULNESS] = HKUnit.init(from: "")
        unitDict[SLEEP_IN_BED] = HKUnit.init(from: "")
        unitDict[SLEEP_ASLEEP] = HKUnit.init(from: "")
        unitDict[SLEEP_AWAKE] = HKUnit.init(from: "")
        unitDict[WORKOUT] = HKUnit.init(from: "")

Best regards,

Sam

cph-cachet / flutter-plugins