Getting activity name through HKWorkoutActivityType in HealthKit

Issue #186

After fetching workouts with HKObjectType.workoutType() , we get HKWorkoutActivityType , which is an enum enum HKWorkoutActivityType : UInt . As of Swift 4.2, there are no way to get enum case as String because this enum has type UInt .

Though there will be some manual involved, we can build a generator to get all the enum case names. Here we will write code to generate code, and use that generated code to examine all the values.

Execute this Swift code in our iOS app

func makeCode(string: String) {
   let pattern = “case \\w*”
   let range = NSMakeRange(0, string.count-1)
   let regex = try! NSRegularExpression(pattern: pattern, options: [])
   regex
   .matches(in: string, options: [], range: range)
   .forEach({ result in
   let start = string.index(string.startIndex, offsetBy: result.range.lowerBound)
   let end = string.index(string.startIndex, offsetBy: result.range.upperBound)
   let substring = String(string[start…end])
   let name = substring
   .replacingOccurrences(of: “case”, with: “”)
   .replacingOccurrences(of: “ “, with: “”)
   .replacingOccurrences(of: “\n”, with: “”
  print(“dictionary[HKWorkoutActivityType.\(name).rawValue] = \”\(name)\””)
 })

Where string is all the cases from HKWorkoutActivityType, for example

case archery The constant for shooting archery.

case bowling The constant for bowling

case fencing The constant for fencing.

case gymnastics Performing gymnastics.

case trackAndField Participating in track and field events, including shot put, javelin, pole vaulting, and related sports.

What the code does is to use regular expression to examine all the names after case , and build our code

dictionary[HKWorkoutActivityType.americanFootball.rawValue] = “americanFootball”
dictionary[HKWorkoutActivityType.archery.rawValue] = “archery”
dictionary[HKWorkoutActivityType.australianFootball.rawValue] = “australianFootball”
dictionary[HKWorkoutActivityType.badminton.rawValue] = “badminton”
dictionary[HKWorkoutActivityType.baseball.rawValue] = “baseball”

The above generated code with dictionary contains rawValue as key and the enum case name as value .

Later when we get any HKWorkoutActivityType , we can compare with this dictionary to find the actual name. This is better than hardcode activity name with numbers because those rawValue are just implementation detail