Merge changes from user submitted HAPI FHIR PR: https://github.com/jamesagnew/hapi-fhir/pull/1148

org.hl7.fhir.convertors/src/main/java/org/hl7/fhir/convertors/VersionConvertor_30_40.java

@@ -33,6 +33,7 @@ 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.Questionnaire;
 import org.hl7.fhir.r4.model.CodeableConcept;
 import org.hl7.fhir.r4.model.Enumeration;
 import org.hl7.fhir.r4.model.Expression.ExpressionLanguage;
@@ -76,7 +77,7 @@ 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 +16014,7 @@ 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 +16031,9 @@ 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 +16136,10 @@ 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.setOperator(org.hl7.fhir.r4.model.Questionnaire.QuestionnaireItemOperator.EQUAL);
     	tgt.setAnswer(convertType(src.getAnswer()));
+    }
     return tgt;
   }
 

org.hl7.fhir.validation.cli/pom.xml

@@ -66,9 +66,10 @@
                             <goal>shade</goal>
                         </goals>
                         <configuration>
-                            <shadedClassifierName/>
+                            <shadedClassifierName>standalone</shadedClassifierName>
                             <transformers>
-                                <transformer implementation="org.apache.maven.plugins.shade.resource.ManifestResourceTransformer">
+                                <transformer
+                                        implementation="org.apache.maven.plugins.shade.resource.ManifestResourceTransformer">
                                     <mainClass>org.hl7.fhir.r4.validation.Validator</mainClass>
                                 </transformer>
                             </transformers>

org.hl7.fhir.validation/src/main/java/org/hl7/fhir/r4/validation/BaseValidator.java

@@ -72,7 +72,7 @@ public class BaseValidator {
    */
   protected boolean fail(List<ValidationMessage> errors, IssueType type, int line, int col, String path, boolean thePass, String msg) {
     if (!thePass) {
-      errors.add(new ValidationMessage(source, type, line, col, path, msg, IssueSeverity.FATAL));
+		 addValidationMessage(errors, type, line, col, path, msg, IssueSeverity.FATAL);
 	 }
     return thePass;
   }
@@ -87,7 +87,7 @@ public class BaseValidator {
   protected boolean fail(List<ValidationMessage> errors, IssueType type, List<String> pathParts, boolean thePass, String msg) {
     if (!thePass) {
       String path = toPath(pathParts);
-      errors.add(new ValidationMessage(source, type, -1, -1, path, msg, IssueSeverity.FATAL));
+		 addValidationMessage(errors, type, -1, -1, path, msg, IssueSeverity.FATAL);
 	 }
     return thePass;
   }
@@ -102,7 +102,7 @@ public class BaseValidator {
   protected boolean fail(List<ValidationMessage> errors, IssueType type, List<String> pathParts, boolean thePass, String theMessage, Object... theMessageArguments) {
     if (!thePass) {
       String path = toPath(pathParts);
-      errors.add(new ValidationMessage(source, type, -1, -1, path, formatMessage(theMessage, theMessageArguments), IssueSeverity.FATAL));
+		 addValidationMessage(errors, type, -1, -1, path, formatMessage(theMessage, theMessageArguments), IssueSeverity.FATAL);
 	 }
     return thePass;
   }
@@ -116,7 +116,7 @@ public class BaseValidator {
    */
   protected boolean fail(List<ValidationMessage> errors, IssueType type, String path, boolean thePass, String msg) {
     if (!thePass) {
-      errors.add(new ValidationMessage(source, type, -1, -1, path, msg, IssueSeverity.FATAL));
+		 addValidationMessage(errors, type, -1, -1, path, msg, IssueSeverity.FATAL);
 	 }
     return thePass;
   }
@@ -145,7 +145,7 @@ public class BaseValidator {
    */
   protected boolean hint(List<ValidationMessage> errors, IssueType type, int line, int col, String path, boolean thePass, String msg) {
     if (!thePass) {
-      errors.add(new ValidationMessage(source, type, line, col, path, msg, IssueSeverity.INFORMATION));
+		 addValidationMessage(errors, type, line, col, path, msg, IssueSeverity.INFORMATION);
 	 }
     return thePass;
   }
@@ -160,7 +160,7 @@ public class BaseValidator {
   protected boolean hint(List<ValidationMessage> errors, IssueType type, int line, int col, String path, boolean thePass, String theMessage, Object... theMessageArguments) {
     if (!thePass) {
       String message = formatMessage(theMessage, theMessageArguments);
-      errors.add(new ValidationMessage(source, type, line, col, path, message, IssueSeverity.INFORMATION));
+		 addValidationMessage(errors, type, line, col, path, message, IssueSeverity.INFORMATION);
 	 }
     return thePass;
   }
@@ -168,7 +168,8 @@ public class BaseValidator {
   protected boolean txHint(List<ValidationMessage> errors, String txLink, IssueType type, int line, int col, String path, boolean thePass, String theMessage, Object... theMessageArguments) {
     if (!thePass) {
       String message = formatMessage(theMessage, theMessageArguments);
-      errors.add(new ValidationMessage(Source.TerminologyEngine, type, line, col, path, message, IssueSeverity.INFORMATION).setTxLink(txLink));
+      addValidationMessage(errors, type, line, col, path, message, IssueSeverity.INFORMATION, Source.TerminologyEngine)
+			.setTxLink(txLink);
     }
     return thePass;
   }
@@ -184,7 +185,7 @@ public class BaseValidator {
     if (!thePass) {
       String path = toPath(pathParts);
       String message = formatMessage(theMessage, theMessageArguments);
-      errors.add(new ValidationMessage(source, type, -1, -1, path, message, IssueSeverity.INFORMATION));
+		 addValidationMessage(errors, type, -1, -1, path, message, IssueSeverity.INFORMATION);
 	 }
     return thePass;
   }
@@ -198,7 +199,7 @@ public class BaseValidator {
    */
   protected boolean hint(List<ValidationMessage> errors, IssueType type, String path, boolean thePass, String msg) {
     if (!thePass) {
-      errors.add(new ValidationMessage(source, type, -1, -1, path, msg, IssueSeverity.INFORMATION));
+		 addValidationMessage(errors, type, -1, -1, path, msg, IssueSeverity.INFORMATION);
 	 }
     return thePass;
   }
@@ -213,7 +214,7 @@ public class BaseValidator {
   protected boolean rule(List<ValidationMessage> errors, IssueType type, int line, int col, String path, boolean thePass, String theMessage, Object... theMessageArguments) {
     if (!thePass) {
       String message = formatMessage(theMessage, theMessageArguments);
-      errors.add(new ValidationMessage(source, type, line, col, path, message, IssueSeverity.ERROR));
+		 addValidationMessage(errors, type, line, col, path, message, IssueSeverity.ERROR);
 	 }
     return thePass;
   }
@@ -236,7 +237,7 @@ public class BaseValidator {
   protected boolean rule(List<ValidationMessage> errors, IssueType type, List<String> pathParts, boolean thePass, String msg) {
     if (!thePass) {
       String path = toPath(pathParts);
-      errors.add(new ValidationMessage(source, type, -1, -1, path, msg, IssueSeverity.ERROR));
+		 addValidationMessage(errors, type, -1, -1, path, msg, IssueSeverity.ERROR);
 	 }
     return thePass;
   }
@@ -252,7 +253,7 @@ public class BaseValidator {
     if (!thePass) {
       String path = toPath(pathParts);
       String message = formatMessage(theMessage, theMessageArguments);
-      errors.add(new ValidationMessage(source, type, -1, -1, path, message, IssueSeverity.ERROR));
+		 addValidationMessage(errors, type, -1, -1, path, message, IssueSeverity.ERROR);
 	 }
     return thePass;
   }
@@ -266,14 +267,14 @@ public class BaseValidator {
    */
   protected boolean rule(List<ValidationMessage> errors, IssueType type, String path, boolean thePass, String msg) {
     if (!thePass) {
-      errors.add(new ValidationMessage(source, type, -1, -1, path, msg, IssueSeverity.ERROR));
+		 addValidationMessage(errors, type, -1, -1, path, msg, IssueSeverity.ERROR);
 	 }
     return thePass;
   }
 
-  static public boolean rule(List<ValidationMessage> errors, Source source, IssueType type, String path, boolean thePass, String msg) {
+  public boolean rule(List<ValidationMessage> errors, Source source, IssueType type, String path, boolean thePass, String msg) {
     if (!thePass) {
-      errors.add(new ValidationMessage(source, type, -1, -1, path, msg, IssueSeverity.ERROR));
+		 addValidationMessage(errors, type, -1, -1, path, msg, IssueSeverity.ERROR, source);
 	 }
     return thePass;
   }
@@ -287,7 +288,7 @@ public class BaseValidator {
    */
   protected boolean rule(List<ValidationMessage> errors, IssueType type, String path, boolean thePass, String msg, String html) {
     if (!thePass) {
-      errors.add(new ValidationMessage(source, type, -1, -1, path, msg, html, IssueSeverity.ERROR));
+		 addValidationMessage(errors, type, path, msg, html, IssueSeverity.ERROR);
 	 }
     return thePass;
   }
@@ -330,12 +331,24 @@ public class BaseValidator {
   protected boolean warning(List<ValidationMessage> errors, IssueType type, int line, int col, String path, boolean thePass, String msg, Object... theMessageArguments) {
     if (!thePass) {
       msg = formatMessage(msg, theMessageArguments);
-      errors.add(new ValidationMessage(source, type, line, col, path, msg, IssueSeverity.WARNING));
+		 IssueSeverity severity = IssueSeverity.WARNING;
+		 addValidationMessage(errors, type, line, col, path, msg, severity);
 	 }
     return thePass;
 
   }
 
+	protected void addValidationMessage(List<ValidationMessage> errors, IssueType type, int line, int col, String path, String msg, IssueSeverity theSeverity) {
+		Source source = this.source;
+		addValidationMessage(errors, type, line, col, path, msg, theSeverity, source);
+	}
+
+	protected ValidationMessage addValidationMessage(List<ValidationMessage> errors, IssueType type, int line, int col, String path, String msg, IssueSeverity theSeverity, Source theSource) {
+		ValidationMessage validationMessage = new ValidationMessage(theSource, type, line, col, path, msg, theSeverity);
+		errors.add(validationMessage);
+		return validationMessage;
+	}
+
 	/**
    * Test a rule and add a {@link IssueSeverity#WARNING} validation message if the validation fails
    * 
@@ -355,7 +368,7 @@ public class BaseValidator {
   protected boolean warningOrError(boolean isError, List<ValidationMessage> errors, IssueType type, int line, int col, String path, boolean thePass, String msg, Object... theMessageArguments) {
     if (!thePass) {
       msg = formatMessage(msg, theMessageArguments);
-      errors.add(new ValidationMessage(source, type, line, col, path, msg, isError ? IssueSeverity.ERROR : IssueSeverity.WARNING));
+		 addValidationMessage(errors, type, line, col, path, msg, isError ? IssueSeverity.ERROR : IssueSeverity.WARNING);
 	 }
     return thePass;
 
@@ -372,7 +385,7 @@ public class BaseValidator {
     if (!thePass) {
       String path = toPath(pathParts);
       String message = formatMessage(theMessage, theMessageArguments);
-      errors.add(new ValidationMessage(source, type, -1, -1, path, message, IssueSeverity.WARNING));
+		 addValidationMessage(errors, type, -1, -1, path, message, IssueSeverity.WARNING);
 	 }
     return thePass;
   }
@@ -386,7 +399,7 @@ public class BaseValidator {
    */
   protected boolean warning(List<ValidationMessage> errors, IssueType type, String path, boolean thePass, String msg) {
     if (!thePass) {
-      errors.add(new ValidationMessage(source, type, -1, -1, path, msg, IssueSeverity.WARNING));
+		 addValidationMessage(errors, type, -1, -1, path, msg, IssueSeverity.WARNING);
 	 }
     return thePass;
   }
@@ -400,7 +413,7 @@ public class BaseValidator {
    */
   protected boolean warning(List<ValidationMessage> errors, IssueType type, String path, boolean thePass, String msg, String html) {
     if (!thePass) {
-      errors.add(new ValidationMessage(source, type, -1, -1, path, msg, html, IssueSeverity.WARNING));
+		 addValidationMessage(errors, type, path, msg, html, IssueSeverity.WARNING);
 	 }
     return thePass;
   }
@@ -415,7 +428,7 @@ public class BaseValidator {
   protected boolean warning(List<ValidationMessage> errors, IssueType type, String path, boolean thePass, String msg, String html, Object... theMessageArguments) {
     if (!thePass) {
       msg = formatMessage(msg, theMessageArguments);
-      errors.add(new ValidationMessage(source, type, -1, -1, path, msg, html, IssueSeverity.WARNING));
+		 addValidationMessage(errors, type, path, msg, html, IssueSeverity.WARNING);
 	 }
     return thePass;
   }
@@ -431,7 +444,7 @@ public class BaseValidator {
   protected boolean suppressedwarning(List<ValidationMessage> errors, IssueType type, int line, int col, String path, boolean thePass, String msg, Object... theMessageArguments) {
     if (!thePass) { 
       msg = formatMessage(msg, theMessageArguments);
-      errors.add(new ValidationMessage(source, type, line, col, path, msg, IssueSeverity.INFORMATION));
+		 addValidationMessage(errors, type, line, col, path, msg, IssueSeverity.INFORMATION);
 	 }
     return thePass;
 
@@ -448,7 +461,7 @@ public class BaseValidator {
     if (!thePass) {
       String path = toPath(pathParts);
       String message = formatMessage(theMessage, theMessageArguments);
-      errors.add(new ValidationMessage(source, type, -1, -1, path, message, IssueSeverity.INFORMATION));
+		 addValidationMessage(errors, type, -1, -1, path, message, IssueSeverity.INFORMATION);
 	 }
     return thePass;
   }
@@ -462,7 +475,7 @@ public class BaseValidator {
    */
   protected boolean suppressedwarning(List<ValidationMessage> errors, IssueType type, String path, boolean thePass, String msg) {
     if (!thePass) {
-      errors.add(new ValidationMessage(source, type, -1, -1, path, msg, IssueSeverity.INFORMATION));
+		 addValidationMessage(errors, type, -1, -1, path, msg, IssueSeverity.INFORMATION);
 	 }
     return thePass;
   }
@@ -476,11 +489,16 @@ public class BaseValidator {
    */
   protected boolean suppressedwarning(List<ValidationMessage> errors, IssueType type, String path, boolean thePass, String msg, String html) {
     if (!thePass) {
-      errors.add(new ValidationMessage(source, type, -1, -1, path, msg, html, IssueSeverity.INFORMATION));
+		 IssueSeverity severity = IssueSeverity.INFORMATION;
+		 addValidationMessage(errors, type, path, msg, html, severity);
 	 }
     return thePass;
   }
 
+	protected void addValidationMessage(List<ValidationMessage> errors, IssueType type, String path, String msg, String html, IssueSeverity theSeverity) {
+		errors.add(new ValidationMessage(source, type, -1, -1, path, msg, html, theSeverity));
+	}
+
 	/**
    * Test a rule and add a {@link IssueSeverity#WARNING} validation message if the validation fails
    * 
@@ -491,7 +509,7 @@ public class BaseValidator {
   protected boolean suppressedwarning(List<ValidationMessage> errors, IssueType type, String path, boolean thePass, String msg, String html, Object... theMessageArguments) {
     if (!thePass) {
       msg = formatMessage(msg, theMessageArguments);
-      errors.add(new ValidationMessage(source, type, -1, -1, path, msg, html, IssueSeverity.INFORMATION));
+		 addValidationMessage(errors, type, path, msg, html, IssueSeverity.INFORMATION);
 	 }
     return thePass;
   }

org.hl7.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) throws FHIRException {
+        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;
+    }
+}

org.hl7.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;
+    }
+}

org.hl7.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);
+
+}

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

@@ -35,6 +35,8 @@ 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;
@@ -275,6 +277,8 @@ public class InstanceValidator extends BaseValidator implements IResourceValidat
   private boolean noExtensibleWarnings;
   private String serverBase;
   
+  private IEnableWhenEvaluator myEnableWhenEvaluator = new DefaultEnableWhenEvaluator();
+
   /*
    * Keeps track of whether a particular profile has been checked or not yet
    */
@@ -2499,6 +2503,10 @@ public class InstanceValidator extends BaseValidator implements IResourceValidat
     this.allowXsiLocation = allowXsiLocation;
   }
   
+  public void setEnableWhenEvaluator(IEnableWhenEvaluator myEnableWhenEvaluator) {
+	this.myEnableWhenEvaluator = myEnableWhenEvaluator;
+  }
+
   /**
    *
    * @param element
@@ -2776,21 +2784,21 @@ 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");
 
@@ -2865,7 +2873,7 @@ 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");
@@ -2874,16 +2882,20 @@ 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);
     }
   }
 
@@ -2895,7 +2907,7 @@ 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
@@ -2908,9 +2920,9 @@ 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");
@@ -2919,11 +2931,9 @@ 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);
         }
       }
@@ -2932,12 +2942,24 @@ 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);
+      } 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)	{
 
@@ -3009,8 +3031,11 @@ public class InstanceValidator extends BaseValidator implements IResourceValidat
         long t = System.nanoTime();
         ValidationResult res = context.validateCode(c, vs);
         txTime = txTime + (System.nanoTime() - t);
-        if (!res.isOk())
+        if (!res.isOk()) {
 			  txRule(errors, res.getTxLink(), IssueType.CODEINVALID, value.line(), value.col(), stack.getLiteralPath(), false, "The value provided (" + c.getSystem() + "::" + c.getCode() + ") is not in the options value set in the questionnaire");
+		  } else if (res.getSeverity() != null) {
+        	  super.addValidationMessage(errors, IssueType.CODEINVALID, value.line(), value.col(), stack.getLiteralPath(), res.getMessage(), res.getSeverity(), Source.TerminologyEngine);
+		  }
       } catch (Exception e) {
         warning(errors, IssueType.CODEINVALID, value.line(), value.col(), stack.getLiteralPath(), false, "Error " + e.getMessage() + " validating Coding against Questionnaire Options");
       }