Active tasks

Abstractly, the built-in active tasks consist of an instruction step (ORKInstructionStep), a get ready countdown step (ORKCountdownStep), task-specific step or steps, followed by a conclusion step (ORKCompletionStep). These tasks are instantiated following the same generic creation pattern employed by ResearchKit:

//  1
let task = ORKOrderedTask.fitnessCheckTaskWithIdentifier("FitnessTask",
            intendedUseDescription: "Blah, blah",walkDuration: 30.0,restDuration: 15.0,options: .None)
//  2
let taskViewController = ORKTaskViewController(task: task, taskRunUUID: nil)
//  3
taskViewController.delegate = self
//  4
let defaultFileManager = NSFileManager.defaultManager()
let documentDirectoryURL = defaultFileManager.URLsForDirectory(.DocumentDirectory, inDomains: .UserDomainMask)
taskViewController.outputDirectory = documentDirectoryURL.first!
//  5
presentViewController(taskViewController, animated: true, completion: nil)

The explanation of the above...