ORKStepNavigationRule Class Reference
Inherits from | NSObject |
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Conforms to | NSCopying NSSecureCoding |
Declared in | ORKStepNavigationRule.h |
The ORKStepNavigationRule
class is the abstract base class for concrete step navigation rules.
Step navigation rules can be used within an ORKNavigableOrderedTask
object. You assign step
navigation rules to be triggered by the task steps. Each step can have one rule at most.
Subclasses must implement the identifierForDestinationStepWithTaskResult:
method, which returns
the identifier of the destination step for the rule.
Two concrete subclasses are included: ORKPredicateStepNavigationRule
can match any answer
combination in the results of the ongoing task and jump accordingly; ORKDirectStepNavigationRule
unconditionally navigates to the step specified by the destination step identifier.
– identifierForDestinationStepWithTaskResult:
Returns the target step identifier.
- (NSString *)identifierForDestinationStepWithTaskResult:(ORKTaskResult *)taskResult
Parameters
taskResult |
The up-to-date task result, used for calculating the destination step. |
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Return Value
The identifier of the destination step.
Discussion
Subclasses must implement this method to calculate the next step based on the passed task result.
The ORKNullStepIdentifier
constant can be returned to indicate that the ongoing task should end
after the step navigation rule is triggered.
Declared In
ORKStepNavigationRule.h