Implement ResearchKit in a ViewController to make a survey

Question

EDIT: Not sure if this may be the root of my issue, but would this piece of code in the app delegate be a reason why this is not working?

    func application(application: UIApplication, didFinishLaunchingWithOptions launchOptions: [NSObject: AnyObject]?) -> Bool {
    // Override point for customization after application launch.
    let navigationController = self.window!.rootViewController as! UINavigationController
    let controller = navigationController.topViewController as! HomeViewController
    controller.managedObjectContext = self.managedObjectContext
    return true

}

I am trying to add survey functionality to an app with integration of ResearchKit. I have worked through the setup guide and some other tutorials from Ray Wenderlich. However when I transitioned into an app I would like to develop I got a bit stuck.

I am getting thrown an error: Cannot assign value of type 'HomeviewController to type 'ORKTaskViewControllerDelegate?'

This is the code I am working with:

class HomeViewController: UIViewController {
var managedObjectContext: NSManagedObjectContext?

@IBAction func surveyTapped(sender: AnyObject) {

    let taskViewController = ORKTaskViewController(task: SurveyTask, taskRunUUID: nil)
    taskViewController.delegate = self
    presentViewController(taskViewController, animated: true, completion: nil)

}
override func prepareForSegue(segue: UIStoryboardSegue, sender: AnyObject?) {
    if segue.destinationViewController.isKindOfClass(NewRideViewController) {
        if let newRideViewController = segue.destinationViewController as? NewRideViewController {
            newRideViewController.managedObjectContext = managedObjectContext
        }
    }
}
}

Based on similar questions with this error syntax, users have added another controller class, but which one is beyond me. Your help is greatly appreciated, thank you StackExchange!

score 1 · Accepted Answer · answered Feb 24 '16 at 07:16

Looks like you have not extended you view controller to implement delegate of ORKTaskViewController which is ORKTaskViewControllerDelegate and your VC code should be as follow -

import ResearchKit

class HomeVC: UIViewController {

    override func viewDidLoad() {
        super.viewDidLoad()
    }

    override func didReceiveMemoryWarning() {
        super.didReceiveMemoryWarning()
    }

    @IBAction func surveyTapped(sender: AnyObject) {
        let taskViewController = ORKTaskViewController(task: SurveyTask, taskRunUUID: nil)
        taskViewController.delegate = self
        presentViewController(taskViewController, animated: true, completion: nil)
    }

}

extension HomeVC: ORKTaskViewControllerDelegate {

    func taskViewController(taskViewController: ORKTaskViewController, didFinishWithReason reason: ORKTaskViewControllerFinishReason, error: NSError?) {

    }

}

Thank you for taking the time to respond and provide code! I have added what you suggested and when I click the _survey_ button the app terminates and gives a _Thread 1: signal SIGABRT_ error, the debug console provides the following message: _Terminating app due to uncaught exception 'NSGenericException', reason: 'Each step should have a unique identifier'_ I thought it may be the connections I have deleted the outlets and code and re-added the outlets correctly. Do you have any idea why this error gets thrown? — Nikolai, Feb 26 '16 at 20:12
Never mind, sorted through the debugger output and found the culprit. Thank your for your assistance! — Nikolai, Feb 27 '16 at 00:13

Implement ResearchKit in a ViewController to make a survey

1 Answers1