ORKStepViewControllerDelegate Protocol Reference
| Conforms to | NSObject |
|---|---|
| Declared in | ORKStepViewController.h |
The primary implementer of the ORKStepViewControllerDelegate protocol is the
task view controller (ORKTaskViewController). The task view controller observes the messages
of the protocol to correctly update its result property, and to control navigation
through the task.
If you present step view controllers outside of a task view controller, it can be helpful to implement this protocol to facilitate navigation and results collection.
– stepViewController:didFinishWithNavigationDirection:
required method
Tells the delegate when the user has done something that requires navigation, such as tap the Back or a Next button, or enter a response to a nonoptional survey question.
- (void)stepViewController:(ORKStepViewController *)stepViewController didFinishWithNavigationDirection:(ORKStepViewControllerNavigationDirection)directionParameters
stepViewController |
The step view controller providing the callback. |
|---|---|
direction |
Direction of navigation requested. |
Declared In
ORKStepViewController.h
– stepViewControllerResultDidChange:
required method
Tells the delegate when a substantial change has occurred to the result.
- (void)stepViewControllerResultDidChange:(ORKStepViewController *)stepViewControllerParameters
stepViewController |
The step view controller providing the callback. |
|---|
Discussion
The result is always available in the step view controller. Although the result is continuously changing while the step view controller is active (because the time stamp in the result property is different each time it’s called), this method is called only when a substantive change to the result occurs, such as when the user enters a survey answer or completes an active step.
In your implementation of this delegate method, you can collect the value of result from the step view controller.
Declared In
ORKStepViewController.h
– stepViewControllerDidFail:withError:
required method
Tells the delegate when a step fails due to an error.
- (void)stepViewControllerDidFail:(ORKStepViewController *)stepViewController withError:(nullable NSError *)errorParameters
stepViewController |
The step view controller providing the callback. |
|---|---|
error |
The error detected. |
Discussion
A step view controller can use this method to report its failure to the task view controller.
The task view controller sends the error to its delegate indicating that the task has failed (using ORKTaskViewControllerFinishReasonFailed).
Note that recorder errors are reported by calling the ORKStepViewControllerDelegate method stepViewController:recorder:didFailWithError:.
Declared In
ORKStepViewController.h
– stepViewController:recorder:didFailWithError:
required method
Tells the delegate when a recorder error has been detected during the step.
- (void)stepViewController:(ORKStepViewController *)stepViewController recorder:(ORKRecorder *)recorder didFailWithError:(NSError *)errorParameters
stepViewController |
The step view controller providing the callback. |
|---|---|
recorder |
The recorder that detected the error. |
error |
The error detected. |
Discussion
Recorder errors can occur during active steps, usually due to the unavailability of sensor data or disk space in which to record results.
Declared In
ORKStepViewController.h
– stepViewControllerWillAppear:
Tells the delegate that the step view controller’s view is about to appear.
- (void)stepViewControllerWillAppear:(ORKStepViewController *)stepViewControllerParameters
stepViewController |
The step view controller providing the callback. |
|---|
Discussion
This method is called from the step view controller’s viewWillAppear: method.
You can use this method to customize the appearance of the step view
controller without subclassing it.
Declared In
ORKStepViewController.h
– stepViewControllerHasPreviousStep:
Asks the delegate whether there is a previous step.
- (BOOL)stepViewControllerHasPreviousStep:(ORKStepViewController *)stepViewControllerParameters
stepViewController |
The step view controller providing the callback. |
|---|
Return Value
YES if a Back button should be visible; otherwise, NO.
Discussion
If there is a previous step, the step view controller adds a Back button to its navigation item; if not, no Back button is added to the navigation item.
Declared In
ORKStepViewController.h
– stepViewControllerHasNextStep:
Asks the delegate whether there is a next step.
- (BOOL)stepViewControllerHasNextStep:(ORKStepViewController *)stepViewControllerParameters
stepViewController |
The step view controller providing the callback. |
|---|
Return Value
YES if there is a step following the current one; otherwise, NO.
Discussion
Depending on the result of the step, the step view controller can adjust the language for the Next button.
Declared In
ORKStepViewController.h