Eevaturkka master (#1196)

* Added unit tests - Case when hasAnswer is false doesn't work with
InstanceValidator yet.

* Fixed test cases to make EnableWhen disable questions

* Fixed unit test asserts

* Unit tests up to date and maybe we need to use r4 path

* First implementation of enableWhen evaluator

* Missing file

* fix enablewhen result

* Added operator evaluation for R4 enableWhen

* Fixed bug in finding QuestionnaireResponse child items

* Remove unnecessary throw

* Added default enablewhen behaviour to STU3 resources converted to R4

* Removed unused HapiWorkerContext

* Cherry picked changes from master to 3.5.0 branch

* Unit tests up to date and maybe we need to use r4 path

* Added operator evaluation for R4 enableWhen

* Removed unused HapiWorkerContext

* Added default operator type EQUALS

* Added check for answering questions which are not enabled

* Way to inject custom enablewhen evaluator added

* Changed versions to use fi.kela.kanta.phr parent

* Copying modifierExtensions from QuestionnaireItems added

* Thread questionnaireResponse root element through questionnaire validation so implementations of enablewhen may validate against the complete resource

* Added missing propagation of QuestionnaireResponse root element

* Avoid infinite loop when validating misaligned questionnaireresponseitems

* Added support for Quantity in the default enable when evaluator

* Added more information to the error message about misplaced QuestionnaireResponseItem

* Temporarily set isNoTerminologyServer() return true to avoid errors about loinc codes

* Returned to original state as the experiment failed

* temporarily set hard coded error when no profile found

* Support required questionnaireitem groups

* bumped version n. for release

* Filter Extensions from enablewhen evaluation

* Don't evaluate Extensions when determining type of answer

* Do not force enableWhen to have system

* Corrected project dependency version numberts

* Corrected problems caused by merge

* Make this configurable

* Deleted unnecessary Inteface class

* Corrected group ids back to ca.uhn.hapi.fhir

hapi-fhir-converter/pom.xml

@@ -16,14 +16,14 @@
 		<dependency>
 			<groupId>ca.uhn.hapi.fhir</groupId>
 			<artifactId>hapi-fhir-base</artifactId>
-			<version>3.7.0-SNAPSHOT</version>
+			<version>${project.version}</version>
 		</dependency>
 
 		<!-- Server -->
 		<dependency>
 			<groupId>ca.uhn.hapi.fhir</groupId>
 			<artifactId>hapi-fhir-server</artifactId>
-			<version>3.7.0-SNAPSHOT</version>
+			<version>${project.version}</version>
 			<optional>true</optional>
 		</dependency>
 		<dependency>
@@ -35,43 +35,43 @@
 		<dependency>
 			<groupId>ca.uhn.hapi.fhir</groupId>
 			<artifactId>hapi-fhir-structures-dstu2</artifactId>
-			<version>3.7.0-SNAPSHOT</version>
+			<version>${project.version}</version>
 			<optional>true</optional>
 		</dependency>
 		<dependency>
 			<groupId>ca.uhn.hapi.fhir</groupId>
 			<artifactId>hapi-fhir-structures-hl7org-dstu2</artifactId>
-			<version>3.7.0-SNAPSHOT</version>
+			<version>${project.version}</version>
 			<optional>true</optional>
 		</dependency>
 		<dependency>
 			<groupId>ca.uhn.hapi.fhir</groupId>
 			<artifactId>hapi-fhir-structures-dstu2.1</artifactId>
-			<version>3.7.0-SNAPSHOT</version>
+			<version>${project.version}</version>
 			<optional>true</optional>
 		</dependency>
 		<dependency>
 			<groupId>ca.uhn.hapi.fhir</groupId>
 			<artifactId>hapi-fhir-structures-dstu3</artifactId>
-			<version>3.7.0-SNAPSHOT</version>
+			<version>${project.version}</version>
 			<optional>true</optional>
 		</dependency>
 		<dependency>
 			<groupId>ca.uhn.hapi.fhir</groupId>
 			<artifactId>hapi-fhir-structures-r4</artifactId>
-			<version>3.7.0-SNAPSHOT</version>
+			<version>${project.version}</version>
 			<optional>true</optional>
 		</dependency>
 		<dependency>
 			<groupId>ca.uhn.hapi.fhir</groupId>
 			<artifactId>hapi-fhir-validation-resources-dstu2</artifactId>
-			<version>3.7.0-SNAPSHOT</version>
+			<version>${project.version}</version>
 			<optional>true</optional>
 		</dependency>
 		<dependency>
 			<groupId>ca.uhn.hapi.fhir</groupId>
 			<artifactId>hapi-fhir-validation-resources-dstu3</artifactId>
-			<version>3.7.0-SNAPSHOT</version>
+			<version>${project.version}</version>
 			<optional>true</optional>
 		</dependency>
 

hapi-fhir-converter/src/main/java/org/hl7/fhir/convertors/VersionConvertor_30_40.java

@@ -32,16 +32,9 @@ import org.hl7.fhir.dstu3.model.ExpansionProfile.SystemVersionProcessingMode;
 import org.hl7.fhir.dstu3.model.Parameters;
 import org.hl7.fhir.dstu3.model.Parameters.ParametersParameterComponent;
 import org.hl7.fhir.exceptions.FHIRException;
-import org.hl7.fhir.r4.model.BooleanType;
+import org.hl7.fhir.r4.model.*;
-import org.hl7.fhir.r4.model.CodeableConcept;
-import org.hl7.fhir.r4.model.Enumeration;
 import org.hl7.fhir.r4.model.Expression.ExpressionLanguage;
 import org.hl7.fhir.r4.model.HealthcareService.HealthcareServiceEligibilityComponent;
-import org.hl7.fhir.r4.model.Identifier;
-import org.hl7.fhir.r4.model.Reference;
-import org.hl7.fhir.r4.model.TerminologyCapabilities;
-import org.hl7.fhir.r4.model.Type;
-import org.hl7.fhir.r4.model.UriType;
 import org.hl7.fhir.utilities.Utilities;
 
 
@@ -76,7 +69,7 @@ import org.hl7.fhir.utilities.Utilities;
 
 
 public class VersionConvertor_30_40 {
-  private static List<String> CANONICAL_URLS = new ArrayList<String>();
+  private static List<String> CANONICAL_URLS = new ArrayList<>();
   static {
     CANONICAL_URLS.add("http://hl7.org/fhir/StructureDefinition/11179-permitted-value-conceptmap");
     CANONICAL_URLS.add("http://hl7.org/fhir/StructureDefinition/11179-permitted-value-valueset");
@@ -16013,6 +16006,7 @@ public class VersionConvertor_30_40 {
       tgt.setType(convertQuestionnaireItemType(src.getType()));
     for (org.hl7.fhir.dstu3.model.Questionnaire.QuestionnaireItemEnableWhenComponent t : src.getEnableWhen())
       tgt.addEnableWhen(convertQuestionnaireItemEnableWhenComponent(t));
+    tgt.setEnableBehavior(Questionnaire.EnableWhenBehavior.ANY);
     if (src.hasRequired())
       tgt.setRequired(src.getRequired());
     if (src.hasRepeats())
@@ -16029,6 +16023,9 @@ public class VersionConvertor_30_40 {
       tgt.addInitial().setValue(convertType(src.getInitial()));
     for (org.hl7.fhir.dstu3.model.Questionnaire.QuestionnaireItemComponent t : src.getItem())
       tgt.addItem(convertQuestionnaireItemComponent(t));
+    for (org.hl7.fhir.dstu3.model.Extension t : src.getModifierExtension()) {
+    	tgt.addModifierExtension(convertExtension(t));
+    }
     return tgt;
   }
 
@@ -16131,8 +16128,10 @@ public class VersionConvertor_30_40 {
       tgt.setOperator(org.hl7.fhir.r4.model.Questionnaire.QuestionnaireItemOperator.EXISTS);
       tgt.setAnswer(convertType(src.getHasAnswerElement()));
     }
-    else if (src.hasAnswer())
+    else if (src.hasAnswer()) {
-      tgt.setAnswer(convertType(src.getAnswer()));
+    	tgt.setOperator(org.hl7.fhir.r4.model.Questionnaire.QuestionnaireItemOperator.EQUAL);
+    	tgt.setAnswer(convertType(src.getAnswer()));
+    }
     return tgt;
   }
 

hapi-fhir-jpaserver-base/src/test/java/ca/uhn/fhir/jpa/subscription/resthook/RestHookWithInterceptorR4Test.java

@@ -144,6 +144,9 @@ public class RestHookWithInterceptorR4Test extends BaseSubscriptionsR4Test {
 
 			interceptor.getFinishedLatch().await(10, TimeUnit.SECONDS);
 			ResourceDeliveryMessage lastDelivery = interceptor.getLastDelivery();
+			assertTrue(lastDelivery.getAttribute("ATTR1").isPresent());
+			assertTrue(lastDelivery.getAttribute("ATTR2").isPresent());
+			assertTrue(lastDelivery.getAttribute("ATTRBLANK").isPresent());
 			assertEquals("Some value 1", lastDelivery.getAttribute("ATTR1").get());
 			assertEquals("Some value 2", lastDelivery.getAttribute("ATTR2").get());
 			assertEquals("", lastDelivery.getAttribute("ATTRBLANK").get());

hapi-fhir-structures-r4/src/test/java/ca/uhn/fhir/rest/server/SearchR4Test.java

@@ -95,7 +95,7 @@ public class SearchR4Test {
 		linkSelf = bundle.getLink(Constants.LINK_SELF).getUrl();
 		assertThat(linkSelf, containsString("_elements=name"));
 		linkNext = bundle.getLink(Constants.LINK_NEXT).getUrl();
-		assertThat(linkNext, containsString("_elements=meta,name"));
+		assertThat(linkNext, containsString("_elements=name"));
 
 		ourLog.info(toJson(bundle));
 
@@ -104,7 +104,7 @@ public class SearchR4Test {
 		bundle = executeAndReturnLinkNext(httpGet, EncodingEnum.JSON);
 		assertThat(toJson(bundle), not(containsString("\"active\"")));
 		linkNext = bundle.getLink(Constants.LINK_NEXT).getUrl();
-		assertThat(linkNext, containsString("_elements=meta,name"));
+		assertThat(linkNext, containsString("_elements=name"));
 		assertThat(linkNext, containsString("_elements:exclude=active,birthDate"));
 
 		// Fetch the next page
@@ -112,7 +112,7 @@ public class SearchR4Test {
 		bundle = executeAndReturnLinkNext(httpGet, EncodingEnum.JSON);
 		assertThat(toJson(bundle), not(containsString("\"active\"")));
 		linkNext = bundle.getLink(Constants.LINK_NEXT).getUrl();
-		assertThat(linkNext, containsString("_elements=meta,name"));
+		assertThat(linkNext, containsString("_elements=name"));
 		assertThat(linkNext, containsString("_elements:exclude=active,birthDate"));
 
 		// Fetch the next page
@@ -120,7 +120,7 @@ public class SearchR4Test {
 		bundle = executeAndReturnLinkNext(httpGet, EncodingEnum.JSON);
 		assertThat(toJson(bundle), not(containsString("\"active\"")));
 		linkNext = bundle.getLink(Constants.LINK_NEXT).getUrl();
-		assertThat(linkNext, containsString("_elements=meta,name"));
+		assertThat(linkNext, containsString("_elements=name"));
 		assertThat(linkNext, containsString("_elements:exclude=active,birthDate"));
 
 	}

hapi-fhir-validation/src/main/java/org/hl7/fhir/dstu3/hapi/validation/FhirInstanceValidator.java

@@ -31,6 +31,8 @@ import org.hl7.fhir.r4.utils.INarrativeGenerator;
 import org.hl7.fhir.r4.utils.IResourceValidator;
 import org.hl7.fhir.r4.utils.IResourceValidator.BestPracticeWarningLevel;
 import org.hl7.fhir.r4.utils.IResourceValidator.IdStatus;
+import org.hl7.fhir.r4.validation.DefaultEnableWhenEvaluator;
+import org.hl7.fhir.r4.validation.IEnableWhenEvaluator;
 import org.hl7.fhir.r4.validation.InstanceValidator;
 import org.hl7.fhir.utilities.TranslationServices;
 import org.hl7.fhir.utilities.validation.ValidationMessage;
@@ -47,6 +49,7 @@ import java.net.MalformedURLException;
 import java.net.URL;
 import java.util.*;
 import java.util.concurrent.TimeUnit;
+import java.util.function.Function;
 
 @SuppressWarnings({"PackageAccessibility", "Duplicates"})
 public class FhirInstanceValidator extends BaseValidatorBridge implements IValidatorModule {
@@ -60,6 +63,9 @@ public class FhirInstanceValidator extends BaseValidatorBridge implements IValid
 	private IValidationSupport myValidationSupport;
 	private boolean noTerminologyChecks = false;
 	private volatile WorkerContextWrapper myWrappedWorkerContext;
+	private Function<IWorkerContext, IEnableWhenEvaluator> enableWhenEvaluatorSupplier;
+
+	private boolean errorForUnknownProfiles;
 	private List<String> extensionDomains = Collections.emptyList();
 
 	/**
@@ -80,6 +86,7 @@ public class FhirInstanceValidator extends BaseValidatorBridge implements IValid
 		myDocBuilderFactory = DocumentBuilderFactory.newInstance();
 		myDocBuilderFactory.setNamespaceAware(true);
 		myValidationSupport = theValidationSupport;
+		setEnableWhenEvaluatorSupplier(ctx -> new DefaultEnableWhenEvaluator());
 	}
 
 	/**
@@ -221,6 +228,14 @@ public class FhirInstanceValidator extends BaseValidatorBridge implements IValid
 	public boolean isAnyExtensionsAllowed() {
 		return myAnyExtensionsAllowed;
 	}
+	
+	public boolean isErrorForUnknownProfiles() {
+		return errorForUnknownProfiles;
+	}
+	
+	public void setErrorForUnknownProfiles(boolean errorForUnknownProfiles) {
+		this.errorForUnknownProfiles = errorForUnknownProfiles;
+	}
 
 	/**
 	 * If set to {@literal true} (default is true) extensions which are not known to the
@@ -237,6 +252,14 @@ public class FhirInstanceValidator extends BaseValidatorBridge implements IValid
 	public boolean isNoTerminologyChecks() {
 		return noTerminologyChecks;
 	}
+	
+	/**
+	 * Sets a customized {@link IEnableWhenEvaluator} which is injected to created InstanceValidators 
+	 */
+	public void setEnableWhenEvaluatorSupplier(
+			Function<IWorkerContext, IEnableWhenEvaluator> enableWhenEvaluatorSupplier) {
+		this.enableWhenEvaluatorSupplier = enableWhenEvaluatorSupplier;
+	}
 
 	/**
 	 * If set to {@literal true} (default is false) the valueSet will not be validate
@@ -270,6 +293,8 @@ public class FhirInstanceValidator extends BaseValidatorBridge implements IValid
 		v.setAnyExtensionsAllowed(isAnyExtensionsAllowed());
 		v.setResourceIdRule(IdStatus.OPTIONAL);
 		v.setNoTerminologyChecks(isNoTerminologyChecks());
+		v.setEnableWhenEvaluator(enableWhenEvaluatorSupplier.apply(wrappedWorkerContext));
+		v.setErrorForUnknownProfiles(isErrorForUnknownProfiles());
 		v.getExtensionDomains().addAll(extensionDomains);
 
 		List<ValidationMessage> messages = new ArrayList<>();

hapi-fhir-validation/src/main/java/org/hl7/fhir/dstu3/validation/InstanceValidator.java

@@ -2539,6 +2539,7 @@ public class InstanceValidator extends BaseValidator implements IResourceValidat
         validateQuestionannaireResponseItem(qsrc, qItem, errors, mapItem, stack, inProgress);
       else
         rule(errors, IssueType.REQUIRED, element.line(), element.col(), stack.getLiteralPath(), !qItem.getRequired(), "No response found for required item "+qItem.getLinkId());
+      
     }
   }
 

hapi-fhir-validation/src/main/java/org/hl7/fhir/dstu3/validation/QuestionnaireResponseValidator.java

@@ -390,3 +390,4 @@ public class QuestionnaireResponseValidator extends BaseValidator {
 		return allowedAnswerTypes;
 	}
 }
+

hapi-fhir-validation/src/main/java/org/hl7/fhir/instance/validation/EnableWhenResult.java

@@ -0,0 +1,48 @@
+package org.hl7.fhir.instance.validation;
+
+
+import org.hl7.fhir.r4.elementmodel.Element;
+import org.hl7.fhir.r4.model.Questionnaire.QuestionnaireItemEnableWhenComponent;
+
+public class EnableWhenResult {
+    private final boolean enabled;
+    private final QuestionnaireItemEnableWhenComponent enableWhenCondition;
+    private final Element answerItem;
+    private final String linkId;
+
+    /**
+     * Evaluation result of enableWhen condition
+     * 
+     * @param enabled
+     *            Evaluation result
+     * @param linkId
+     *            LinkId of the questionnaire item
+     * @param enableWhenCondition
+     *            Evaluated enableWhen condition
+     * @param answerItem
+     *            item in QuestionnaireResponse
+     */
+    public EnableWhenResult(boolean enabled, String linkId, QuestionnaireItemEnableWhenComponent enableWhenCondition,
+            Element answerItem) {
+        this.enabled = enabled;
+        this.linkId = linkId;
+        this.answerItem = answerItem;
+        this.enableWhenCondition = enableWhenCondition;
+    }
+
+    public boolean isEnabled() {
+        return enabled;
+    }
+
+    public String getLinkId() {
+        return linkId;
+    }
+
+    public Element getAnswerItem() {
+        return answerItem;
+    }
+
+    public QuestionnaireItemEnableWhenComponent getEnableWhenCondition() {
+        return enableWhenCondition;
+    }
+}

hapi-fhir-validation/src/main/java/org/hl7/fhir/r4/validation/DefaultEnableWhenEvaluator.java

@@ -0,0 +1,216 @@
+package org.hl7.fhir.r4.validation;
+
+import java.util.*;
+import java.util.stream.*;
+
+import org.hl7.fhir.exceptions.FHIRException;
+import org.hl7.fhir.r4.elementmodel.Element;
+import org.hl7.fhir.r4.model.*;
+import org.hl7.fhir.r4.model.Questionnaire.*;
+
+import ca.uhn.fhir.rest.server.exceptions.UnprocessableEntityException;
+
+/**
+ * Evaluates Questionnaire.item.enableWhen against a QuestionnaireResponse.
+ * Ignores possible modifierExtensions and extensions.
+ *
+ */
+public class DefaultEnableWhenEvaluator implements IEnableWhenEvaluator {
+    public static final String LINKID_ELEMENT = "linkId";
+    public static final String ITEM_ELEMENT = "item";
+    public static final String ANSWER_ELEMENT = "answer";
+
+    @Override
+    public boolean isQuestionEnabled(QuestionnaireItemComponent questionnaireItem, Element questionnaireResponse) {
+        if (!questionnaireItem.hasEnableWhen()) {
+            return true;
+        }
+        List<EnableWhenResult> evaluationResults = questionnaireItem.getEnableWhen()
+                .stream()
+                .map(enableCondition -> evaluateCondition(enableCondition, questionnaireResponse,
+                        questionnaireItem.getLinkId()))
+                .collect(Collectors.toList());
+        return checkConditionResults(evaluationResults, questionnaireItem);
+    }
+   
+    
+    public boolean checkConditionResults(List<EnableWhenResult> evaluationResults,
+            QuestionnaireItemComponent questionnaireItem) {        
+        if (questionnaireItem.hasEnableBehavior() && questionnaireItem.getEnableBehavior() == EnableWhenBehavior.ANY){
+            return evaluationResults.stream().anyMatch(EnableWhenResult::isEnabled);
+        } if (questionnaireItem.hasEnableBehavior() && questionnaireItem.getEnableBehavior() == EnableWhenBehavior.ALL){
+            return evaluationResults.stream().allMatch(EnableWhenResult::isEnabled);
+        }
+        //TODO: Throw exception? enableBehavior is mandatory when there are multiple conditions
+        return true;
+    }
+
+
+    protected EnableWhenResult evaluateCondition(QuestionnaireItemEnableWhenComponent enableCondition,
+            Element questionnaireResponse, String linkId) {
+        //TODO: Fix EnableWhenResult stuff
+        List<Element> answerItems = findQuestionAnswers(questionnaireResponse,
+                enableCondition.getQuestion());        
+        QuestionnaireItemOperator operator = enableCondition.getOperator();
+        if (operator == QuestionnaireItemOperator.EXISTS){
+            Type answer = enableCondition.getAnswer();
+            if (!(answer instanceof BooleanType)){
+                throw new UnprocessableEntityException("Exists-operator requires answerBoolean");                
+            }
+            return new EnableWhenResult(((BooleanType)answer).booleanValue() != answerItems.isEmpty(), 
+                    linkId, enableCondition, questionnaireResponse);
+        }        
+        boolean result = answerItems
+                .stream()
+                .anyMatch(answer -> evaluateAnswer(answer, enableCondition.getAnswer(), enableCondition.getOperator()));            
+        return new EnableWhenResult(result, linkId, enableCondition, questionnaireResponse);
+    }
+    
+    public Type convertToType(Element element)  {
+        Type b = new Factory().create(element.fhirType());
+        if (b instanceof PrimitiveType) {
+          ((PrimitiveType<?>) b).setValueAsString(element.primitiveValue());
+        } else {
+          for (Element child : element.getChildren()) {
+        	  if (!isExtension(child)) {
+        		  b.setProperty(child.getName(), convertToType(child));
+        	  }
+          }
+        }
+        return b;
+      }
+
+
+	private boolean isExtension(Element element) {
+		return "Extension".equals(element.fhirType());
+	}
+
+    protected boolean evaluateAnswer(Element answer, Type expectedAnswer, QuestionnaireItemOperator questionnaireItemOperator) {
+        Type actualAnswer;
+        if (isExtension(answer)) {
+        	return false;
+        }
+        try {
+        	actualAnswer = convertToType(answer);
+        } catch (FHIRException e) {
+            throw new UnprocessableEntityException("Unexpected answer type", e);
+        }
+        if (!actualAnswer.getClass().equals(expectedAnswer.getClass())) {
+            throw new UnprocessableEntityException("Expected answer and actual answer have incompatible types");
+        }                
+        if (expectedAnswer instanceof Coding) {
+            return compareCodingAnswer((Coding)expectedAnswer, (Coding)actualAnswer, questionnaireItemOperator);
+        } else if ((expectedAnswer instanceof PrimitiveType)) {
+            return comparePrimitiveAnswer((PrimitiveType<?>)actualAnswer, (PrimitiveType<?>)expectedAnswer, questionnaireItemOperator);
+        } else if (expectedAnswer instanceof Quantity) {
+        	return compareQuantityAnswer((Quantity)actualAnswer, (Quantity)expectedAnswer, questionnaireItemOperator);
+        }
+        // TODO: Attachment, reference?
+        throw new UnprocessableEntityException("Unimplemented answer type: " + expectedAnswer.getClass());
+    }
+   
+
+	private boolean compareQuantityAnswer(Quantity actualAnswer, Quantity expectedAnswer, QuestionnaireItemOperator questionnaireItemOperator) {                
+           return compareComparable(actualAnswer.getValue(), expectedAnswer.getValue(), questionnaireItemOperator);
+    }
+
+    
+	private boolean comparePrimitiveAnswer(PrimitiveType<?> actualAnswer, PrimitiveType<?> expectedAnswer, QuestionnaireItemOperator questionnaireItemOperator) {                
+        if (actualAnswer.getValue() instanceof Comparable){            
+           return compareComparable((Comparable)actualAnswer.getValue(), (Comparable) expectedAnswer.getValue(), questionnaireItemOperator);                  
+        } else if (questionnaireItemOperator == QuestionnaireItemOperator.EQUAL){
+            return actualAnswer.equalsShallow(expectedAnswer);
+        } else if (questionnaireItemOperator == QuestionnaireItemOperator.NOT_EQUAL){
+            return !actualAnswer.equalsShallow(expectedAnswer);
+        }
+        throw new UnprocessableEntityException("Bad operator for PrimitiveType comparison");
+    }
+
+	@SuppressWarnings({ "rawtypes", "unchecked" })
+	private boolean compareComparable(Comparable actual, Comparable expected,
+			QuestionnaireItemOperator questionnaireItemOperator) {
+		int result = actual.compareTo(expected);
+		
+		if (questionnaireItemOperator == QuestionnaireItemOperator.EQUAL){
+		    return result == 0;
+		} else if (questionnaireItemOperator == QuestionnaireItemOperator.NOT_EQUAL){
+		    return result != 0;
+		} else if (questionnaireItemOperator == QuestionnaireItemOperator.GREATER_OR_EQUAL){
+		    return result >= 0;
+		} else if (questionnaireItemOperator == QuestionnaireItemOperator.LESS_OR_EQUAL){
+		    return result <= 0;
+		} else if (questionnaireItemOperator == QuestionnaireItemOperator.LESS_THAN){
+		    return result < 0;
+		} else if (questionnaireItemOperator == QuestionnaireItemOperator.GREATER_THAN){
+		    return result > 0;
+		}
+		
+        throw new UnprocessableEntityException("Bad operator for PrimitiveType comparison");
+
+	}
+
+    private List<Element> findQuestionAnswers(Element questionnaireResponse, String question) {
+        List<Element> matchingItems = questionnaireResponse.getChildren(ITEM_ELEMENT)
+                .stream()
+                .flatMap(i -> findSubItems(i).stream())
+                .filter(i -> hasLinkId(i, question))
+                .collect(Collectors.toList());        
+        return matchingItems
+                .stream()
+                .flatMap(e -> extractAnswer(e).stream())
+                .collect(Collectors.toList());        
+    }
+    
+    private List<Element> extractAnswer(Element item) {
+        return item.getChildrenByName(ANSWER_ELEMENT)
+                .stream()
+                .flatMap(c -> c.getChildren().stream())
+                .collect(Collectors.toList());
+    }
+    
+    private boolean compareCodingAnswer(Coding expectedAnswer, Coding actualAnswer, QuestionnaireItemOperator questionnaireItemOperator) {
+        boolean result = compareSystems(expectedAnswer, actualAnswer) && compareCodes(expectedAnswer, actualAnswer);
+        if (questionnaireItemOperator == QuestionnaireItemOperator.EQUAL){
+            return result == true;
+        } else if (questionnaireItemOperator == QuestionnaireItemOperator.NOT_EQUAL){
+            return result == false;
+        }
+        throw new UnprocessableEntityException("Bad operator for Coding comparison");
+    }
+
+    private boolean compareCodes(Coding expectedCoding, Coding value) {
+        if (expectedCoding.hasCode() != value.hasCode()) {
+            return false;
+        }
+        if (expectedCoding.hasCode()) {
+            return expectedCoding.getCode().equals(value.getCode());
+        }
+        return true;
+    }
+
+    private boolean compareSystems(Coding expectedCoding, Coding value) {
+        if (expectedCoding.hasSystem() && !value.hasSystem()) {
+            return false;
+        }
+        if (expectedCoding.hasSystem()) {
+            return expectedCoding.getSystem().equals(value.getSystem());
+        }
+        return true;
+    }
+    private List<Element> findSubItems(Element item) {
+        List<Element> results = item.getChildren(LINKID_ELEMENT)
+                .stream()
+                .flatMap(i -> findSubItems(i).stream())
+                .collect(Collectors.toList());
+        results.add(item);
+        return results;
+    }
+
+    private boolean hasLinkId(Element item, String linkId) {
+        Element linkIdChild = item.getNamedChild(LINKID_ELEMENT);
+        if (linkIdChild != null && linkIdChild.getValue().equals(linkId)){
+            return true;
+        }
+        return false;
+    }
+}

hapi-fhir-validation/src/main/java/org/hl7/fhir/r4/validation/EnableWhenResult.java

@@ -0,0 +1,48 @@
+package org.hl7.fhir.r4.validation;
+
+
+import org.hl7.fhir.r4.elementmodel.Element;
+import org.hl7.fhir.r4.model.Questionnaire.QuestionnaireItemEnableWhenComponent;
+
+public class EnableWhenResult {
+    private final boolean enabled;
+    private final QuestionnaireItemEnableWhenComponent enableWhenCondition;
+    private final Element answerItem;
+    private final String linkId;
+
+    /**
+     * Evaluation result of enableWhen condition
+     * 
+     * @param enabled
+     *            Evaluation result
+     * @param linkId
+     *            LinkId of the questionnaire item
+     * @param enableWhenCondition
+     *            Evaluated enableWhen condition
+     * @param responseItem
+     *            item in QuestionnaireResponse
+     */
+    public EnableWhenResult(boolean enabled, String linkId, QuestionnaireItemEnableWhenComponent enableWhenCondition,
+            Element answerItem) {
+        this.enabled = enabled;
+        this.linkId = linkId;
+        this.answerItem = answerItem;
+        this.enableWhenCondition = enableWhenCondition;
+    }
+
+    public boolean isEnabled() {
+        return enabled;
+    }
+
+    public String getLinkId() {
+        return linkId;
+    }
+
+    public Element getAnswerItem() {
+        return answerItem;
+    }
+
+    public QuestionnaireItemEnableWhenComponent getEnableWhenCondition() {
+        return enableWhenCondition;
+    }
+}

hapi-fhir-validation/src/main/java/org/hl7/fhir/r4/validation/IEnableWhenEvaluator.java

@@ -0,0 +1,10 @@
+package org.hl7.fhir.r4.validation;
+
+import org.hl7.fhir.r4.elementmodel.Element;
+import org.hl7.fhir.r4.model.Questionnaire.QuestionnaireItemComponent;
+
+public interface IEnableWhenEvaluator {
+	public boolean isQuestionEnabled(QuestionnaireItemComponent questionnaireItem,
+			Element questionnaireResponse);
+
+}

hapi-fhir-validation/src/main/java/org/hl7/fhir/r4/validation/InstanceValidator.java

@@ -15,6 +15,8 @@ import java.util.UUID;
 
 import org.apache.commons.lang3.NotImplementedException;
 import org.apache.commons.lang3.StringUtils;
+import org.hl7.fhir.r4.model.Reference;
+import org.hl7.fhir.exceptions.*;
 import org.hl7.fhir.convertors.VersionConvertorConstants;
 import org.hl7.fhir.exceptions.DefinitionException;
 import org.hl7.fhir.exceptions.FHIRException;
@@ -254,6 +256,8 @@ public class InstanceValidator extends BaseValidator implements IResourceValidat
   private IEvaluationContext externalHostServices;
   private boolean noExtensibleWarnings;
   private String serverBase;
+  
+  private IEnableWhenEvaluator myEnableWhenEvaluator = new DefaultEnableWhenEvaluator();
 
   /*
    * Keeps track of whether a particular profile has been checked or not yet
@@ -2464,6 +2468,10 @@ public class InstanceValidator extends BaseValidator implements IResourceValidat
   public void setAllowXsiLocation(boolean allowXsiLocation) {
     this.allowXsiLocation = allowXsiLocation;
   }
+  
+  public void setEnableWhenEvaluator(IEnableWhenEvaluator myEnableWhenEvaluator) {
+	this.myEnableWhenEvaluator = myEnableWhenEvaluator;
+  }
 
   /**
    *
@@ -2734,21 +2742,21 @@ public class InstanceValidator extends BaseValidator implements IResourceValidat
       sdTime = sdTime + (System.nanoTime() - t);
       if (warning(errors, IssueType.REQUIRED, q.line(), q.col(), stack.getLiteralPath(), qsrc != null, "The questionnaire \""+questionnaire+"\" could not be resolved, so no validation can be performed against the base questionnaire")) {
         boolean inProgress = "in-progress".equals(element.getNamedChildValue("status"));
-        validateQuestionannaireResponseItems(qsrc, qsrc.getItem(), errors, element, stack, inProgress);
+        validateQuestionannaireResponseItems(qsrc, qsrc.getItem(), errors, element, stack, inProgress, element);
       }
     }
   }
 
-  private void validateQuestionannaireResponseItem(Questionnaire qsrc, QuestionnaireItemComponent qItem, List<ValidationMessage> errors, Element element, NodeStack stack, boolean inProgress) {
+  private void validateQuestionannaireResponseItem(Questionnaire qsrc, QuestionnaireItemComponent qItem, List<ValidationMessage> errors, Element element, NodeStack stack, boolean inProgress, Element questionnaireResponseRoot) {
     String text = element.getNamedChildValue("text");
     rule(errors, IssueType.INVALID, element.line(), element.col(), stack.getLiteralPath(), Utilities.noString(text) || text.equals(qItem.getText()), "If text exists, it must match the questionnaire definition for linkId "+qItem.getLinkId());
 
     List<Element> answers = new ArrayList<Element>();
     element.getNamedChildren("answer", answers);
     if (inProgress)
-      warning(errors, IssueType.REQUIRED, element.line(), element.col(), stack.getLiteralPath(), (answers.size() > 0) || !qItem.getRequired(), "No response answer found for required item "+qItem.getLinkId());
+      warning(errors, IssueType.REQUIRED, element.line(), element.col(), stack.getLiteralPath(), isAnswerRequirementFulfilled(qItem, answers), "No response answer found for required item "+qItem.getLinkId());
     else
-      rule(errors, IssueType.REQUIRED, element.line(), element.col(), stack.getLiteralPath(), (answers.size() > 0) || !qItem.getRequired(), "No response answer found for required item "+qItem.getLinkId());
+      rule(errors, IssueType.REQUIRED, element.line(), element.col(), stack.getLiteralPath(), isAnswerRequirementFulfilled(qItem, answers), "No response answer found for required item "+qItem.getLinkId());
     if (answers.size() > 1)
       rule(errors, IssueType.INVALID, answers.get(1).line(), answers.get(1).col(), stack.getLiteralPath(), qItem.getRepeats(), "Only one response answer item with this linkId allowed");
 
@@ -2823,7 +2831,7 @@ public class InstanceValidator extends BaseValidator implements IResourceValidat
 				// no validation
 				break;
       }
-      validateQuestionannaireResponseItems(qsrc, qItem.getItem(), errors, answer, stack, inProgress);
+      validateQuestionannaireResponseItems(qsrc, qItem.getItem(), errors, answer, stack, inProgress, questionnaireResponseRoot);
     }
     if (qItem.getType() == null) {
       fail(errors, IssueType.REQUIRED, element.line(), element.col(), stack.getLiteralPath(), false, "Definition for item "+qItem.getLinkId() + " does not contain a type");
@@ -2832,16 +2840,20 @@ public class InstanceValidator extends BaseValidator implements IResourceValidat
       element.getNamedChildren("item", items);
       rule(errors, IssueType.STRUCTURE, element.line(), element.col(), stack.getLiteralPath(), items.isEmpty(), "Items not of type DISPLAY should not have items - linkId {0}", qItem.getLinkId());
     } else {
-      validateQuestionannaireResponseItems(qsrc, qItem.getItem(), errors, element, stack, inProgress);
+      validateQuestionannaireResponseItems(qsrc, qItem.getItem(), errors, element, stack, inProgress, questionnaireResponseRoot);
     }
   }
 
-  private void validateQuestionannaireResponseItem(Questionnaire qsrc, QuestionnaireItemComponent qItem, List<ValidationMessage> errors, List<Element> elements, NodeStack stack, boolean inProgress) {
+private boolean isAnswerRequirementFulfilled(QuestionnaireItemComponent qItem, List<Element> answers) {
+	return !answers.isEmpty() || !qItem.getRequired() || qItem.getType() == QuestionnaireItemType.GROUP;
+}
+
+  private void validateQuestionannaireResponseItem(Questionnaire qsrc, QuestionnaireItemComponent qItem, List<ValidationMessage> errors, List<Element> elements, NodeStack stack, boolean inProgress, Element questionnaireResponseRoot) {
     if (elements.size() > 1)
       rule(errors, IssueType.INVALID, elements.get(1).line(), elements.get(1).col(), stack.getLiteralPath(), qItem.getRepeats(), "Only one response item with this linkId allowed - " + qItem.getLinkId());
     for (Element element : elements) {
       NodeStack ns = stack.push(element, -1, null, null);
-      validateQuestionannaireResponseItem(qsrc, qItem, errors, element, ns, inProgress);
+      validateQuestionannaireResponseItem(qsrc, qItem, errors, element, ns, inProgress, questionnaireResponseRoot);
     }
   }
 
@@ -2852,8 +2864,8 @@ public class InstanceValidator extends BaseValidator implements IResourceValidat
     }
     return -1;
   }
-
+  
-  private void validateQuestionannaireResponseItems(Questionnaire qsrc, List<QuestionnaireItemComponent> qItems, List<ValidationMessage> errors, Element element, NodeStack stack, boolean inProgress) {
+  private void validateQuestionannaireResponseItems(Questionnaire qsrc, List<QuestionnaireItemComponent> qItems, List<ValidationMessage> errors, Element element, NodeStack stack, boolean inProgress, Element questionnaireResponseRoot) {
     List<Element> items = new ArrayList<Element>();
     element.getNamedChildren("item", items);
     // now, sort into stacks
@@ -2866,9 +2878,9 @@ public class InstanceValidator extends BaseValidator implements IResourceValidat
         if (index == -1) {
           QuestionnaireItemComponent qItem = findQuestionnaireItem(qsrc, linkId);
           if (qItem != null) {
-            rule(errors, IssueType.STRUCTURE, item.line(), item.col(), stack.getLiteralPath(), index > -1, "Structural Error: item is in the wrong place");
+            rule(errors, IssueType.STRUCTURE, item.line(), item.col(), stack.getLiteralPath(), index > -1, misplacedItemError(qItem));
             NodeStack ns = stack.push(item, -1, null, null);
-            validateQuestionannaireResponseItem(qsrc, qItem, errors, element, ns, inProgress);
+            validateQuestionannaireResponseItem(qsrc, qItem, errors, item, ns, inProgress, questionnaireResponseRoot);
           }
           else
             rule(errors, IssueType.NOTFOUND, item.line(), item.col(), stack.getLiteralPath(), index > -1, "LinkId \""+linkId+"\" not found in questionnaire");
@@ -2877,11 +2889,9 @@ public class InstanceValidator extends BaseValidator implements IResourceValidat
         {
           rule(errors, IssueType.STRUCTURE, item.line(), item.col(), stack.getLiteralPath(), index >= lastIndex, "Structural Error: items are out of order");
           lastIndex = index;
-          List<Element> mapItem = map.get(linkId);
+          
-          if (mapItem == null) {
+          List<Element> mapItem = map.computeIfAbsent(linkId, key -> new ArrayList<>());
-            mapItem = new ArrayList<Element>();
+          
-            map.put(linkId, mapItem);
-          }
           mapItem.add(item);
         }
       }
@@ -2890,13 +2900,25 @@ public class InstanceValidator extends BaseValidator implements IResourceValidat
     // ok, now we have a list of known items, grouped by linkId. We"ve made an error for anything out of order
     for (QuestionnaireItemComponent qItem : qItems) {
       List<Element> mapItem = map.get(qItem.getLinkId());
-      if (mapItem != null)
+      if (mapItem != null){
-        validateQuestionannaireResponseItem(qsrc, qItem, errors, mapItem, stack, inProgress);
+    	  rule(errors, IssueType.INVALID, element.line(), element.col(), stack.getLiteralPath(), myEnableWhenEvaluator.isQuestionEnabled(qItem, questionnaireResponseRoot), "Item has answer, even though it is not enabled "+qItem.getLinkId());
-      else
+        validateQuestionannaireResponseItem(qsrc, qItem, errors, mapItem, stack, inProgress, questionnaireResponseRoot);
-        rule(errors, IssueType.REQUIRED, element.line(), element.col(), stack.getLiteralPath(), !qItem.getRequired(), "No response found for required item "+qItem.getLinkId());
+      } else { 
+    	//item is missing, is the question enabled?
+    	if (myEnableWhenEvaluator.isQuestionEnabled(qItem, questionnaireResponseRoot)) {    	  
+    	  rule(errors, IssueType.REQUIRED, element.line(), element.col(), stack.getLiteralPath(), !qItem.getRequired(), "No response found for required item "+qItem.getLinkId());
+    	}
+      }
     }
   }
 
+private String misplacedItemError(QuestionnaireItemComponent qItem) {
+	return qItem.hasLinkId() ? 
+			String.format("Structural Error: item with linkid %s is in the wrong place", qItem.getLinkId())
+			:
+			"Structural Error: item is in the wrong place";
+}
+
   private void validateQuestionnaireResponseItemQuantity( List<ValidationMessage> errors, Element answer, NodeStack stack)	{
 
   }

hapi-fhir-validation/src/test/java/org/hl7/fhir/dstu3/hapi/validation/EnableWhenResult.java

@@ -0,0 +1,47 @@
+package org.hl7.fhir.dstu3.hapi.validation;
+
+import org.hl7.fhir.dstu3.model.Questionnaire.QuestionnaireItemEnableWhenComponent;
+import org.hl7.fhir.dstu3.model.QuestionnaireResponse.QuestionnaireResponseItemComponent;
+
+public class EnableWhenResult {
+    private final boolean enabled;
+    private final QuestionnaireItemEnableWhenComponent enableWhenCondition;
+    private final QuestionnaireResponseItemComponent responseItem;
+    private final String linkId;
+
+    /**
+     * Evaluation result of enableWhen condition
+     * 
+     * @param enabled
+     *            Evaluation result
+     * @param linkId
+     *            LinkId of the questionnaire item
+     * @param enableWhenCondition
+     *            Evaluated enableWhen condition
+     * @param responseItem
+     *            item in QuestionnaireResponse
+     */
+    public EnableWhenResult(boolean enabled, String linkId, QuestionnaireItemEnableWhenComponent enableWhenCondition,
+            QuestionnaireResponseItemComponent responseItem) {
+        this.enabled = enabled;
+        this.linkId = linkId;
+        this.responseItem = responseItem;
+        this.enableWhenCondition = enableWhenCondition;
+    }
+
+    public boolean isEnabled() {
+        return enabled;
+    }
+
+    public String getLinkId() {
+        return linkId;
+    }
+
+    public QuestionnaireResponseItemComponent getResponseItem() {
+        return responseItem;
+    }
+
+    public QuestionnaireItemEnableWhenComponent getEnableWhenCondition() {
+        return enableWhenCondition;
+    }
+}

hapi-fhir-validation/src/test/java/org/hl7/fhir/dstu3/hapi/validation/QuestionnaireResponseValidatorDstu3Test.java

@@ -7,35 +7,37 @@ import ca.uhn.fhir.validation.FhirValidator;
 import ca.uhn.fhir.validation.ResultSeverityEnum;
 import ca.uhn.fhir.validation.SingleValidationMessage;
 import ca.uhn.fhir.validation.ValidationResult;
-import org.apache.commons.io.IOUtils;
+
 import org.hamcrest.Matchers;
-import org.hl7.fhir.dstu3.context.IWorkerContext;
-import org.hl7.fhir.dstu3.hapi.ctx.HapiWorkerContext;
 import org.hl7.fhir.dstu3.hapi.ctx.IValidationSupport;
 import org.hl7.fhir.dstu3.hapi.ctx.IValidationSupport.CodeValidationResult;
 import org.hl7.fhir.dstu3.model.*;
 import org.hl7.fhir.dstu3.model.CodeSystem.CodeSystemContentMode;
 import org.hl7.fhir.dstu3.model.CodeSystem.ConceptDefinitionComponent;
 import org.hl7.fhir.dstu3.model.Questionnaire.QuestionnaireItemComponent;
+import org.hl7.fhir.dstu3.model.Questionnaire.QuestionnaireItemEnableWhenComponent;
 import org.hl7.fhir.dstu3.model.Questionnaire.QuestionnaireItemOptionComponent;
 import org.hl7.fhir.dstu3.model.Questionnaire.QuestionnaireItemType;
+import org.hl7.fhir.dstu3.model.QuestionnaireResponse.QuestionnaireResponseItemAnswerComponent;
 import org.hl7.fhir.dstu3.model.QuestionnaireResponse.QuestionnaireResponseItemComponent;
 import org.hl7.fhir.dstu3.model.QuestionnaireResponse.QuestionnaireResponseStatus;
 import org.junit.AfterClass;
 import org.junit.Before;
+import org.junit.BeforeClass;
 import org.junit.Test;
 
 import java.util.ArrayList;
 import java.util.Arrays;
 import java.util.Date;
 import java.util.List;
-import java.util.stream.Collectors;
 
 import static org.hamcrest.Matchers.containsString;
 import static org.hamcrest.Matchers.empty;
 import static org.hamcrest.Matchers.hasSize;
+import static org.hl7.fhir.dstu3.model.Questionnaire.QuestionnaireItemType.BOOLEAN;
+import static org.hl7.fhir.dstu3.model.Questionnaire.QuestionnaireItemType.CHOICE;
+import static org.hl7.fhir.dstu3.model.QuestionnaireResponse.QuestionnaireResponseStatus.COMPLETED;
 import static org.junit.Assert.*;
-import static org.mockito.ArgumentMatchers.contains;
 import static org.mockito.Matchers.any;
 import static org.mockito.Matchers.eq;
 import static org.mockito.Mockito.mock;
@@ -43,23 +45,26 @@ import static org.mockito.Mockito.reset;
 import static org.mockito.Mockito.when;
 
 public class QuestionnaireResponseValidatorDstu3Test {
+	private static final String QUESTIONNAIRE_URL = "http://example.com/Questionnaire/q1";
 	public static final IdType ID_ICC_QUESTIONNAIRE_SETUP = new IdType("Questionnaire/profile");
 	private static final org.slf4j.Logger ourLog = org.slf4j.LoggerFactory.getLogger(QuestionnaireResponseValidatorDstu3Test.class);
 	private static final String CODE_ICC_SCHOOLTYPE_PT = "PT";
 	private static final IdType ID_VS_SCHOOLTYPE = new IdType("ValueSet/schooltype");
 	private static final String SYSTEMURI_ICC_SCHOOLTYPE = "http://ehealthinnovation/icc/ns/schooltype";
 	private static DefaultProfileValidationSupport myDefaultValidationSupport = new DefaultProfileValidationSupport();
-	private static FhirContext ourCtx = FhirContext.forDstu3();
+	private static FhirContext ourCtx;
 	private FhirInstanceValidator myInstanceVal;
 	private FhirValidator myVal;
 	private IValidationSupport myValSupport;
-	private IWorkerContext myWorkerCtx;
+	
-
+	@BeforeClass
+	public static void beforeClass() {
+		ourCtx = FhirContext.forDstu3();
+	}
+	
 	@Before
 	public void before() {
 		myValSupport = mock(IValidationSupport.class);
-		// new DefaultProfileValidationSupport();
-		myWorkerCtx = new HapiWorkerContext(ourCtx, myValSupport);
 
 		myVal = ourCtx.newValidator();
 		myVal.setValidateAgainstStandardSchema(false);
@@ -128,7 +133,7 @@ public class QuestionnaireResponseValidatorDstu3Test {
 		answerValues[11] = new Coding().setSystem("http://codesystems.com/system").setCode("code0");
 		answerValues[12] = new StringType("some value");
 		answerValues[13] = new Attachment().setData("some data".getBytes()).setContentType("txt");
-		answerValues[14] = new Reference("http://example.com/Questionnaire/q1");
+		answerValues[14] = new Reference(QUESTIONNAIRE_URL);
 		answerValues[15] = new Quantity(42);
 
 		for (int i = 0; i < itemCnt; i++) {
@@ -138,7 +143,7 @@ public class QuestionnaireResponseValidatorDstu3Test {
 			reset(myValSupport);
 			Questionnaire q = new Questionnaire();
 			when(myValSupport.fetchResource(any(FhirContext.class), eq(Questionnaire.class),
-				eq("http://example.com/Questionnaire/q1"))).thenReturn(q);
+				eq(QUESTIONNAIRE_URL))).thenReturn(q);
 			when(myValSupport.fetchCodeSystem(any(FhirContext.class), eq("http://codesystems.com/system"))).thenReturn(codeSystem);
 			when(myValSupport.fetchResource(any(FhirContext.class), eq(ValueSet.class), eq("http://somevalueset"))).thenReturn(options);
 			myInstanceVal.flushCaches();
@@ -155,7 +160,7 @@ public class QuestionnaireResponseValidatorDstu3Test {
 
 			QuestionnaireResponse qa = new QuestionnaireResponse();
 			qa.setStatus(QuestionnaireResponseStatus.INPROGRESS);
-			qa.getQuestionnaire().setReference("http://example.com/Questionnaire/q1");
+			qa.getQuestionnaire().setReference(QUESTIONNAIRE_URL);
 			qa.addItem().setLinkId(linkId).addAnswer().setValue(answerValues[i]);
 
 			ValidationResult errors = myVal.validateWithResult(qa);
@@ -171,7 +176,7 @@ public class QuestionnaireResponseValidatorDstu3Test {
 
 		QuestionnaireResponse qa = new QuestionnaireResponse();
 		qa.setStatus(QuestionnaireResponseStatus.COMPLETED);
-		qa.getQuestionnaire().setReference("http://example.com/Questionnaire/q1");
+		qa.getQuestionnaire().setReference(QUESTIONNAIRE_URL);
 		qa.addItem().setLinkId("link0").addAnswer().setValue(new StringType("FOO"));
 
 		when(myValSupport.fetchResource(any(FhirContext.class), eq(Questionnaire.class), eq(qa.getQuestionnaire().getReference()))).thenReturn(q);
@@ -184,11 +189,11 @@ public class QuestionnaireResponseValidatorDstu3Test {
 
 	@Test
 	public void testCodedAnswer() {
-		String questionnaireRef = "http://example.com/Questionnaire/q1";
+		String questionnaireRef = QUESTIONNAIRE_URL;
 
 		Questionnaire q = new Questionnaire();
 		q.addItem().setLinkId("link0").setRequired(false).setType(QuestionnaireItemType.CHOICE).setOptions(new Reference("http://somevalueset"));
-		when(myValSupport.fetchResource(any(FhirContext.class), eq(Questionnaire.class), eq("http://example.com/Questionnaire/q1"))).thenReturn(q);
+		when(myValSupport.fetchResource(any(FhirContext.class), eq(Questionnaire.class), eq(QUESTIONNAIRE_URL))).thenReturn(q);
 
 		CodeSystem codeSystem = new CodeSystem();
 		codeSystem.setContent(CodeSystemContentMode.COMPLETE);
@@ -252,7 +257,7 @@ public class QuestionnaireResponseValidatorDstu3Test {
 
 		QuestionnaireResponse qa = new QuestionnaireResponse();
 		qa.setStatus(QuestionnaireResponseStatus.COMPLETED);
-		qa.getQuestionnaire().setReference("http://example.com/Questionnaire/q1");
+		qa.getQuestionnaire().setReference(QUESTIONNAIRE_URL);
 		QuestionnaireResponseItemComponent qaGroup = qa.addItem();
 		qaGroup.addItem().setLinkId("link0").addAnswer().setValue(new StringType("FOO"));
 
@@ -262,6 +267,43 @@ public class QuestionnaireResponseValidatorDstu3Test {
 		ourLog.info(errors.toString());
 		assertThat(errors.toString(), containsString("No LinkId, so can't be validated"));
 	}
+	
+	@Test
+	public void testMissingAnswerInNestedStructureIsReported() throws Exception {
+		Questionnaire q = new Questionnaire();
+		q.addItem().setType(QuestionnaireItemType.GROUP).setRequired(true)
+		 .addItem().setType(QuestionnaireItemType.GROUP).setRequired(true)
+		 .addItem().setType(QuestionnaireItemType.BOOLEAN).setLinkId("link0").setRequired(true);
+		
+		QuestionnaireResponse qa = new QuestionnaireResponse();
+		qa.setStatus(QuestionnaireResponseStatus.COMPLETED);
+		qa.getQuestionnaire().setReference(QUESTIONNAIRE_URL);
+		
+		when(myValSupport.fetchResource(any(FhirContext.class), eq(Questionnaire.class), eq(qa.getQuestionnaire().getReference()))).thenReturn(q);
+		
+		ValidationResult errors = myVal.validateWithResult(qa);
+		
+		assertThat(errors.toString(), Matchers.not(containsString("No issues")));
+	}
+	
+	@Test
+	public void testGroupMarkedAsRequiredIsOk() throws Exception {
+		Questionnaire q = new Questionnaire();
+		q.addItem().setType(QuestionnaireItemType.GROUP).setRequired(true).setLinkId("link1")
+		 .addItem().setType(QuestionnaireItemType.BOOLEAN).setLinkId("link0").setRequired(true);
+		
+		QuestionnaireResponse qa = new QuestionnaireResponse();
+		qa.setStatus(QuestionnaireResponseStatus.COMPLETED);
+		qa.getQuestionnaire().setReference(QUESTIONNAIRE_URL);
+		qa.addItem().setLinkId("link1")
+		  .addItem().setLinkId("link0").addAnswer().setValue(new BooleanType(true));
+		
+		when(myValSupport.fetchResource(any(FhirContext.class), eq(Questionnaire.class), eq(qa.getQuestionnaire().getReference()))).thenReturn(q);
+		
+		ValidationResult errors = myVal.validateWithResult(qa);
+		
+		assertThat(errors.toString(), containsString("No issues"));
+	}
 
 	@Test
 	public void testItemWithNoType() {
@@ -272,7 +314,7 @@ public class QuestionnaireResponseValidatorDstu3Test {
 
 		QuestionnaireResponse qa = new QuestionnaireResponse();
 		qa.setStatus(QuestionnaireResponseStatus.COMPLETED);
-		qa.getQuestionnaire().setReference("http://example.com/Questionnaire/q1");
+		qa.getQuestionnaire().setReference(QUESTIONNAIRE_URL);
 		QuestionnaireResponseItemComponent qaGroup = qa.addItem().setLinkId("link0");
 		qaGroup.addItem().setLinkId("link1").addAnswer().setValue(new StringType("FOO"));
 
@@ -293,7 +335,7 @@ public class QuestionnaireResponseValidatorDstu3Test {
 
 		QuestionnaireResponse qa = new QuestionnaireResponse();
 		qa.setStatus(QuestionnaireResponseStatus.COMPLETED);
-		qa.getQuestionnaire().setReference("http://example.com/Questionnaire/q1");
+		qa.getQuestionnaire().setReference(QUESTIONNAIRE_URL);
 		qa.addItem().setLinkId("link1").addAnswer().setValue(new StringType("FOO"));
 
 		String reference = qa.getQuestionnaire().getReference();
@@ -303,10 +345,271 @@ public class QuestionnaireResponseValidatorDstu3Test {
 		ourLog.info(errors.toString());
 		assertThat(errors.toString(), containsString("No response found for required item link0"));
 	}
+	
+	@Test
+	public void testEnableWhenWithHasAnswerTrueDisablesQuestionWhenNoAnswerIsPresent() {
 
+		Questionnaire q = new Questionnaire();
+		q.addItem().setLinkId("link0").setRequired(false).setType(QuestionnaireItemType.STRING);
+		q.addItem().setLinkId("link1").setRequired(true).addEnableWhen().setQuestion("link0").setHasAnswer(true);
+		
+
+		QuestionnaireResponse qa = new QuestionnaireResponse();
+		qa.setStatus(QuestionnaireResponseStatus.COMPLETED);
+		qa.getQuestionnaire().setReference(QUESTIONNAIRE_URL);
+
+		String reference = qa.getQuestionnaire().getReference();
+		when(myValSupport.fetchResource(any(FhirContext.class), eq(Questionnaire.class), eq(reference))).thenReturn(q);
+		ValidationResult errors = myVal.validateWithResult(qa);
+
+		ourLog.info(errors.toString());
+		assertThat(errors.toString(), containsString("No issues"));
+	}
+	
+	@Test
+	public void testRequiredQuestionQuantityWithEnableWhenHidesQuestionHasAnswerTrue() {
+
+		Questionnaire q = new Questionnaire();
+		q.addItem().setLinkId("link0").setRequired(false).setType(QuestionnaireItemType.QUANTITY);
+		
+		//link1 question is enabled when link0 has answer
+		QuestionnaireItemComponent item1 = new QuestionnaireItemComponent();
+		item1.setLinkId("link1").setRequired(true);
+		q.addItem(item1);
+		QuestionnaireItemEnableWhenComponent enable = new QuestionnaireItemEnableWhenComponent();
+		item1.addEnableWhen(enable);
+		enable.setQuestion("link0");
+		enable.setHasAnswer(true);
+		enable.setAnswer(new Quantity().setValue(1L));
+
+		QuestionnaireResponse qa = new QuestionnaireResponse();
+		qa.setStatus(QuestionnaireResponseStatus.COMPLETED);
+		qa.getQuestionnaire().setReference(QUESTIONNAIRE_URL);
+
+		String reference = qa.getQuestionnaire().getReference();
+		when(myValSupport.fetchResource(any(FhirContext.class), eq(Questionnaire.class), eq(reference))).thenReturn(q);
+		ValidationResult errors = myVal.validateWithResult(qa);
+
+		ourLog.info(errors.toString());
+		assertThat(errors.toString(), containsString("No issues"));
+	}
+	
+	@Test
+	public void testRequiredQuestionQuantityWithEnableWhenHidesQuestionValue() {
+
+		Questionnaire q = new Questionnaire();
+		q.addItem().setLinkId("link0").setRequired(false).setType(QuestionnaireItemType.QUANTITY);
+		
+		//link1 question is enabled when link0 has answer
+		QuestionnaireItemComponent item1 = new QuestionnaireItemComponent();
+		item1.setLinkId("link1").setRequired(true);
+		q.addItem(item1);
+		QuestionnaireItemEnableWhenComponent enable = new QuestionnaireItemEnableWhenComponent();
+		item1.addEnableWhen(enable);
+		enable.setQuestion("link0");
+		enable.setAnswer(new Quantity().setValue(2L));
+
+		QuestionnaireResponse qa = new QuestionnaireResponse();
+		qa.setStatus(QuestionnaireResponseStatus.COMPLETED);
+		qa.getQuestionnaire().setReference(QUESTIONNAIRE_URL);
+		qa.addItem().setLinkId("link0").addAnswer().setValue(new Quantity().setValue(1L));
+
+		String reference = qa.getQuestionnaire().getReference();
+		when(myValSupport.fetchResource(any(FhirContext.class), eq(Questionnaire.class), eq(reference))).thenReturn(q);
+		ValidationResult errors = myVal.validateWithResult(qa);
+
+		ourLog.info(errors.toString());
+		assertThat(errors.toString(), containsString("No issues"));
+	}
+	
+	@Test
+	public void testRequiredQuestionQuantityWithEnableWhenEnablesQuestionValue() {
+
+		Questionnaire q = new Questionnaire();
+		q.addItem().setLinkId("link0").setRequired(false).setType(QuestionnaireItemType.QUANTITY);
+		
+		//link1 question is enabled when link0 has answer
+		QuestionnaireItemComponent item1 = new QuestionnaireItemComponent();
+		item1.setLinkId("link1").setRequired(true);
+		q.addItem(item1);
+		QuestionnaireItemEnableWhenComponent enable = new QuestionnaireItemEnableWhenComponent();
+		item1.addEnableWhen(enable);
+		enable.setQuestion("link0");
+		enable.setAnswer(new Quantity().setValue(1L));
+
+		QuestionnaireResponse qa = new QuestionnaireResponse();
+		qa.setStatus(QuestionnaireResponseStatus.COMPLETED);
+		qa.getQuestionnaire().setReference(QUESTIONNAIRE_URL);
+		qa.addItem().setLinkId("link0").addAnswer().setValue(new Quantity().setValue(1L));
+
+		String reference = qa.getQuestionnaire().getReference();
+		when(myValSupport.fetchResource(any(FhirContext.class), eq(Questionnaire.class), eq(reference))).thenReturn(q);
+		ValidationResult errors = myVal.validateWithResult(qa);
+
+		ourLog.info(errors.toString());
+		assertThat(errors.toString(), containsString("No response found for required item link1"));
+	}
+	
+	@Test
+	public void testRequiredQuestionWithEnableWhenHasAnswerTrueWithAnswer() {
+
+		Questionnaire q = new Questionnaire();
+		q.addItem().setLinkId("link0").setRequired(true).setType(QuestionnaireItemType.STRING);
+		
+		// create the questionnaire
+		QuestionnaireItemComponent item1 = new QuestionnaireItemComponent();
+		item1.setLinkId("link1").setRequired(true).setType(QuestionnaireItemType.STRING);
+		q.addItem(item1);
+		QuestionnaireItemEnableWhenComponent enable = new QuestionnaireItemEnableWhenComponent();
+		item1.addEnableWhen(enable);
+		enable.setQuestion("link0");
+		enable.setHasAnswer(true);
+
+		QuestionnaireResponse qa = new QuestionnaireResponse();
+		qa.setStatus(QuestionnaireResponseStatus.COMPLETED);
+		qa.getQuestionnaire().setReference(QUESTIONNAIRE_URL);
+		qa.addItem().setLinkId("link0").addAnswer().setValue(new StringType("FOO"));
+		qa.addItem().setLinkId("link1").addAnswer().setValue(new StringType("BAR"));
+
+		String reference = qa.getQuestionnaire().getReference();
+		when(myValSupport.fetchResource(any(FhirContext.class), eq(Questionnaire.class), eq(reference))).thenReturn(q);
+		ValidationResult errors = myVal.validateWithResult(qa);
+
+		ourLog.info(errors.toString());
+		assertThat(errors.toString(), containsString("No issues"));
+	}
+	
+	
+	@Test
+	public void testRequiredQuestionWithEnableWheHidesRequiredQuestionnHasAnswerFalse() {
+
+		Questionnaire q = new Questionnaire();
+		q.addItem().setLinkId("link0").setRequired(false).setType(QuestionnaireItemType.STRING);
+		
+		// create the questionnaire
+		QuestionnaireItemComponent item1 = new QuestionnaireItemComponent();
+		item1.setLinkId("link1").setRequired(true);
+		q.addItem(item1);
+		QuestionnaireItemEnableWhenComponent enable = new QuestionnaireItemEnableWhenComponent();
+		item1.addEnableWhen(enable);
+		enable.setQuestion("link0");
+		enable.setHasAnswer(false);
+
+		QuestionnaireResponse qa = new QuestionnaireResponse();
+		qa.setStatus(QuestionnaireResponseStatus.COMPLETED);
+		qa.getQuestionnaire().setReference(QUESTIONNAIRE_URL);
+		
+		// link1 should be disabled, because the enableWhen enables it when link0 doesn't haven an answer
+		qa.addItem().setLinkId("link0").addAnswer().setValue(new StringType("FOO"));
+
+		String reference = qa.getQuestionnaire().getReference();
+		when(myValSupport.fetchResource(any(FhirContext.class), eq(Questionnaire.class), eq(reference))).thenReturn(q);
+		ValidationResult errors = myVal.validateWithResult(qa);
+
+		ourLog.info(errors.toString());
+		assertThat(errors.toString(), containsString("No issues"));
+	}
+	
+	@Test
+	public void testGivenQuestionIsNotEnabledWithEnableWhenAnswersAreReportedAsErrors() throws Exception {
+		Questionnaire q = new Questionnaire();
+		q.addItem().setLinkId("link0").setRequired(false).setType(QuestionnaireItemType.STRING);
+		q.addItem().setLinkId("link2").setRequired(false).setType(QuestionnaireItemType.STRING).addEnableWhen().setQuestion("link0").setHasAnswer(true);
+		
+		QuestionnaireResponse qr = new QuestionnaireResponse();
+		qr.setStatus(QuestionnaireResponseStatus.COMPLETED);
+		qr.getQuestionnaire().setReference(QUESTIONNAIRE_URL);
+		
+		qr.addItem().setLinkId("link2").addAnswer().setValue(new StringType("FOO"));
+		
+		String reference = qr.getQuestionnaire().getReference();
+		when(myValSupport.fetchResource(any(FhirContext.class), eq(Questionnaire.class), eq(reference))).thenReturn(q);
+		
+		ValidationResult errors = myVal.validateWithResult(qr);
+		
+		assertThat(errors.toString(), Matchers.not(containsString("No issues")));
+	}
+	
+	@Test
+	public void testGivenQuestionnaireResponseHasSiblingItemsWhenTheyShouldBeChildItems() throws Exception {
+		Questionnaire q = new Questionnaire();
+		QuestionnaireItemComponent item = q.addItem().setLinkId("link0").setRequired(true).setType(QuestionnaireItemType.GROUP);
+		item.addItem().setLinkId("link1").setRequired(true).setType(QuestionnaireItemType.STRING);
+		
+		QuestionnaireResponse qr = new QuestionnaireResponse();
+		qr.setStatus(QuestionnaireResponseStatus.COMPLETED);
+		qr.getQuestionnaire().setReference(QUESTIONNAIRE_URL);
+		qr.addItem().setLinkId("link0").setText("Text");
+		qr.addItem().setLinkId("link1").addAnswer().setValue(new StringType("Answer"));
+		String reference = qr.getQuestionnaire().getReference();
+		when(myValSupport.fetchResource(any(FhirContext.class), eq(Questionnaire.class), eq(reference))).thenReturn(q);
+		
+		ValidationResult errors = myVal.validateWithResult(qr);
+		assertThat(errors.toString(), Matchers.not(containsString("No issues")));
+		assertTrue("Must contain structural error about misplaced link1 item",
+				errors.getMessages().stream().filter(vm -> vm.getMessage().contains("Structural Error"))
+						.anyMatch(vm -> vm.getMessage().contains("link1")));
+	}
+	
+	@Test
+	public void testAnswerIsValueCodingWithExtensionInside() throws Exception {
+		Questionnaire q = new Questionnaire();
+		Coding qcoding = new Coding();
+		qcoding.setCode("1293");
+		q.addItem().setLinkId("1B").setRequired(true).setType(CHOICE).addOption().setValue(qcoding);
+		q.addItem().setLinkId("2B").setType(BOOLEAN).addEnableWhen().setQuestion("1B").setAnswer(qcoding);
+		
+		QuestionnaireResponse qr = new QuestionnaireResponse();
+		qr.setStatus(COMPLETED);
+		qr.getQuestionnaire().setReference(QUESTIONNAIRE_URL);
+		QuestionnaireResponseItemComponent qrItem = qr.addItem().setLinkId("1B");
+		Coding coding = new Coding();
+		coding.setCode("1293");
+		QuestionnaireResponseItemAnswerComponent answer = qrItem.addAnswer();
+		answer.setValue(coding);
+		coding.addExtension("http://hl7.org/fhir/StructureDefinition/questionnaire-hidden", new BooleanType(true));
+		qr.addItem().setLinkId("2B").addAnswer().setValue(new BooleanType(true));
+				
+		String reference = qr.getQuestionnaire().getReference();
+		when(myValSupport.fetchResource(any(FhirContext.class), eq(Questionnaire.class), eq(reference))).thenReturn(q);
+		
+		ValidationResult errors = myVal.validateWithResult(qr);
+		assertThat(errors.toString(), containsString("No issues"));
+		
+	}
+	
+	@Test
+	public void testChoiceItemsEnableWhenHasNoSystemYetAnswerHasSystem() throws Exception {
+		Questionnaire q = new Questionnaire();
+		Coding qcoding = new Coding();
+		qcoding.setCode("male");
+		qcoding.setSystem("http://hl7.org/fhir/administrative-gender");
+		q.addItem().setLinkId("1B").setRequired(true).setType(CHOICE).addOption().setValue(qcoding);
+		Coding enablewhenCoding = new Coding();
+		enablewhenCoding.setCode("male");
+		q.addItem().setLinkId("2B").setType(BOOLEAN).addEnableWhen().setQuestion("1B").setAnswer(enablewhenCoding);
+		
+		QuestionnaireResponse qr = new QuestionnaireResponse();
+		qr.setStatus(COMPLETED);
+		qr.getQuestionnaire().setReference(QUESTIONNAIRE_URL);
+		QuestionnaireResponseItemComponent qrItem = qr.addItem().setLinkId("1B");
+		Coding coding = new Coding();
+		coding.setCode("male");
+		coding.setSystem("http://hl7.org/fhir/administrative-gender");
+		QuestionnaireResponseItemAnswerComponent answer = qrItem.addAnswer();
+		answer.setValue(coding);
+		qr.addItem().setLinkId("2B").addAnswer().setValue(new BooleanType(true));
+				
+		String reference = qr.getQuestionnaire().getReference();
+		when(myValSupport.fetchResource(any(FhirContext.class), eq(Questionnaire.class), eq(reference))).thenReturn(q);
+		
+		ValidationResult errors = myVal.validateWithResult(qr);
+		assertThat(errors.toString(), containsString("No issues"));
+	}
+	
 	@Test
 	public void testEmbeddedItemInChoice() {
-		String questionnaireRef = "http://example.com/Questionnaire/q1";
+		String questionnaireRef = QUESTIONNAIRE_URL;
 		String valueSetRef = "http://somevalueset";
 		String codeSystemUrl = "http://codesystems.com/system";
 		String codeValue = "code0";
@@ -362,7 +665,7 @@ public class QuestionnaireResponseValidatorDstu3Test {
 
 	@Test
 	public void testEmbeddedItemInOpenChoice() {
-		String questionnaireRef = "http://example.com/Questionnaire/q1";
+		String questionnaireRef = QUESTIONNAIRE_URL;
 		String valueSetRef = "http://somevalueset";
 		String codeSystemUrl = "http://codesystems.com/system";
 		String codeValue = "code0";
@@ -418,7 +721,7 @@ public class QuestionnaireResponseValidatorDstu3Test {
 
 	@Test
 	public void testEmbeddedItemInString() {
-		String questionnaireRef = "http://example.com/Questionnaire/q1";
+		String questionnaireRef = QUESTIONNAIRE_URL;
 
 		// create the questionnaire
 		QuestionnaireItemComponent item1 = new QuestionnaireItemComponent();
@@ -519,7 +822,7 @@ public class QuestionnaireResponseValidatorDstu3Test {
 			.setType(QuestionnaireItemType.STRING)
 			.setRequired(true);
 
-		String reference = "http://example.com/Questionnaire/q1";
+		String reference = QUESTIONNAIRE_URL;
 		when(myValSupport.fetchResource(any(FhirContext.class), eq(Questionnaire.class), eq(reference)))
 			.thenReturn(q);
 
@@ -543,7 +846,7 @@ public class QuestionnaireResponseValidatorDstu3Test {
 
 	@Test
 	public void testOpenchoiceAnswer() {
-		String questionnaireRef = "http://example.com/Questionnaire/q1";
+		String questionnaireRef = QUESTIONNAIRE_URL;
 
 		Questionnaire q = new Questionnaire();
 		QuestionnaireItemComponent item = q.addItem();
@@ -666,7 +969,7 @@ public class QuestionnaireResponseValidatorDstu3Test {
 
 		QuestionnaireResponse qa = new QuestionnaireResponse();
 		qa.setStatus(QuestionnaireResponseStatus.COMPLETED);
-		qa.getQuestionnaire().setReference("http://example.com/Questionnaire/q1");
+		qa.getQuestionnaire().setReference(QUESTIONNAIRE_URL);
 		qa.addItem().setLinkId("link1").addAnswer().setValue(new StringType("FOO"));
 
 		when(myValSupport.fetchResource(any(FhirContext.class), eq(Questionnaire.class), eq(qa.getQuestionnaire().getReference()))).thenReturn(q);
@@ -684,7 +987,7 @@ public class QuestionnaireResponseValidatorDstu3Test {
 
 		QuestionnaireResponse qa = new QuestionnaireResponse();
 		qa.setStatus(QuestionnaireResponseStatus.COMPLETED);
-		qa.getQuestionnaire().setReference("http://example.com/Questionnaire/q1");
+		qa.getQuestionnaire().setReference(QUESTIONNAIRE_URL);
 		qa.addItem().setLinkId("link1").addItem().setLinkId("link2");
 
 		when(myValSupport.fetchResource(any(FhirContext.class), eq(Questionnaire.class), eq(qa.getQuestionnaire().getReference()))).thenReturn(q);