Result predicate for ORKConsentReviewStep

Add a result predicate for determining if the user selected accept or decline in a consent signature step, allowing for custom navigation rules, such as skipping to the end of a survey if the user does not consent.

ResearchKit/Common/ORKResultPredicate.h

@@ -514,6 +514,19 @@ within the specified `NSTimeInterval` values.
                                         minimumExpectedAnswerDate:(nullable NSDate *)minimumExpectedAnswerDate
                                         maximumExpectedAnswerDate:(nullable NSDate *)maximumExpectedAnswerDate;
 
+/**
+ Returns a predicate matching a result of type `ORKConsentSignatureResult` whose `consented` value 
+ matches the specified boolean value.
+ 
+ @param resultSelector              The result selector object which specifies the question result
+ you are interested in.
+ @param didConsent                  Whether the user consented to the `ORKConsentReviewStep`
+ 
+ @return A result predicate.
+ */
++ (NSPredicate *)predicateForConsentWithResultSelector:(ORKResultSelector *)resultSelector
+                                            didConsent:(BOOL)didConsent;
+
 @end
 
 NS_ASSUME_NONNULL_END

ResearchKit/Common/ORKResultPredicate.m

@@ -448,4 +448,10 @@ NSString *const ORKResultPredicateTaskIdentifierVariableName = @"ORK_TASK_IDENTI
                  subPredicateFormatArgumentArray:subPredicateFormatArgumentArray];
 }
 
++ (NSPredicate *)predicateForConsentWithResultSelector:(ORKResultSelector *)resultSelector didConsent:(BOOL)didConsent {
+    return [self predicateMatchingResultSelector:resultSelector
+                         subPredicateFormatArray:@[ @"consented == %@" ]
+                 subPredicateFormatArgumentArray:@[ @(didConsent) ]];
+}
+
 @end

ResearchKitTests/ORKTaskTests.m

@@ -584,6 +584,9 @@ BOOL (^testStepBeforeStep)(ORKNavigableOrderedTask *, ORKTaskResult *, ORKStep *
     XCTAssertTrue(testStepAfterStep(skipTask, taskResult, severityStep, nil));
 }
 
+ORKDefineStringKey(SignConsentStepIdentifier);
+ORKDefineStringKey(SignatureIdentifier);
+
 ORKDefineStringKey(ScaleStepIdentifier);
 ORKDefineStringKey(ContinuousScaleStepIdentifier);
 static const NSInteger IntegerValue = 6;
@@ -653,6 +656,12 @@ static ORKStepResult *(^getStepResult)(NSString *, Class, ORKQuestionType, id) =
     return stepResult;
 };
 
+static ORKStepResult *(^getConsentStepResult)(NSString *, NSString *, BOOL) = ^ORKStepResult *(NSString *stepIdentifier, NSString *signatureIdentifier, BOOL consented) {
+    ORKConsentSignatureResult *consentSignatureResult = [[ORKConsentSignatureResult alloc] initWithIdentifier:signatureIdentifier];
+    consentSignatureResult.consented = consented;
+    return [[ORKStepResult alloc] initWithStepIdentifier:stepIdentifier results:@[consentSignatureResult]];
+};
+
 - (ORKTaskResult *)getGeneralTaskResultTree {
     NSMutableArray *stepResults = [NSMutableArray new];
     
@@ -687,6 +696,19 @@ static ORKStepResult *(^getStepResult)(NSString *, Class, ORKQuestionType, id) =
     return taskResult;
 }
 
+- (ORKTaskResult *)getTaskResultTreeWithConsent:(BOOL)consented {
+    NSMutableArray *stepResults = [NSMutableArray new];
+    
+    [stepResults addObject:getConsentStepResult(SignConsentStepIdentifier, SignatureIdentifier, consented)];
+    
+    ORKTaskResult *taskResult = [[ORKTaskResult alloc] initWithTaskIdentifier:OrderedTaskIdentifier
+                                                                  taskRunUUID:[NSUUID UUID]
+                                                              outputDirectory:[NSURL fileURLWithPath:NSTemporaryDirectory()]];
+    taskResult.results = stepResults;
+    
+    return taskResult;
+}
+
 - (ORKTaskResult *)getSmallTaskResultTreeWithIsAdditionalTask:(BOOL)isAdditionalTask {
     NSMutableArray *stepResults = [NSMutableArray new];
     
@@ -1334,6 +1356,28 @@ static ORKStepResult *(^getStepResult)(NSString *, Class, ORKQuestionType, id) =
     XCTAssertFalse([[ORKResultPredicate predicateForNilQuestionResultWithResultSelector:resultSelector] evaluateWithObject:taskResults substitutionVariables:substitutionVariables]);
 }
 
+- (void)testConsentPredicate {
+    ORKResultSelector *resultSelector = [[ORKResultSelector alloc] initWithTaskIdentifier:OrderedTaskIdentifier
+                                                                           stepIdentifier:SignConsentStepIdentifier
+                                                                         resultIdentifier:SignatureIdentifier];
+    {
+        ORKTaskResult *consentedTaskResult = [self getTaskResultTreeWithConsent:YES];
+        XCTAssertTrue([[ORKResultPredicate predicateForConsentWithResultSelector:resultSelector
+                                                                      didConsent:YES] evaluateWithObject:@[consentedTaskResult] substitutionVariables:nil]);
+        XCTAssertFalse([[ORKResultPredicate predicateForConsentWithResultSelector:resultSelector
+                                                                       didConsent:NO] evaluateWithObject:@[consentedTaskResult] substitutionVariables:nil]);
+    }
+    
+    {
+        ORKTaskResult *didNotConsentTaskResult = [self getTaskResultTreeWithConsent:NO];
+        
+        XCTAssertTrue([[ORKResultPredicate predicateForConsentWithResultSelector:resultSelector
+                                                                      didConsent:NO] evaluateWithObject:@[didNotConsentTaskResult] substitutionVariables:nil]);
+        XCTAssertFalse([[ORKResultPredicate predicateForConsentWithResultSelector:resultSelector
+                                                                       didConsent:YES] evaluateWithObject:@[didNotConsentTaskResult] substitutionVariables:nil]);
+    }
+}
+
 - (void)testResultPredicates {
     ORKTaskResult *taskResult = [self getGeneralTaskResultTree];
     NSArray *taskResults = @[ taskResult ];