Add FHIRPath evaluation interceptor (#1769)

* Add FHIRPath evaluation interceptor

* Add changelog

hapi-fhir-base/src/main/java/ca/uhn/fhir/context/FhirContext.java

@@ -3,7 +3,7 @@ package ca.uhn.fhir.context;
 import ca.uhn.fhir.context.api.AddProfileTagEnum;
 import ca.uhn.fhir.context.support.DefaultProfileValidationSupport;
 import ca.uhn.fhir.context.support.IValidationSupport;
-import ca.uhn.fhir.fluentpath.IFluentPath;
+import ca.uhn.fhir.fhirpath.IFhirPath;
 import ca.uhn.fhir.i18n.HapiLocalizer;
 import ca.uhn.fhir.model.api.IElement;
 import ca.uhn.fhir.model.api.IFhirVersion;
@@ -625,12 +625,21 @@ public class FhirContext {
 	}
 
 	/**
-	 * Creates a new FluentPath engine which can be used to exvaluate
+	 * @since 2.2
+	 * @deprecated Deprecated in HAPI FHIR 5.0.0. Use {@link #newFhirPath()} instead.
+	 */
+	@Deprecated
+	public IFhirPath newFluentPath() {
+		return newFhirPath();
+	}
+
+	/**
+	 * Creates a new FhirPath engine which can be used to evaluate
 	 * path expressions over FHIR resources. Note that this engine will use the
 	 * {@link IValidationSupport context validation support} module which is
 	 * configured on the context at the time this method is called.
 	 * <p>
-	 * In other words, call {@link #setValidationSupport(IValidationSupport)} before
+	 * In other words, you may wish to call {@link #setValidationSupport(IValidationSupport)} before
 	 * calling {@link #newFluentPath()}
 	 * </p>
 	 * <p>
@@ -640,9 +649,9 @@ public class FhirContext {
 	 * {@link UnsupportedOperationException}
 	 * </p>
 	 *
-	 * @since 2.2
+	 * @since 5.0.0
 	 */
-	public IFluentPath newFluentPath() {
+	public IFhirPath newFhirPath() {
 		return myVersion.createFluentPathExecutor(this);
 	}
 

hapi-fhir-base/src/main/java/ca/uhn/fhir/fhirpath/FhirPathExecutionException.java

@@ -1,4 +1,4 @@
-package ca.uhn.fhir.fluentpath;
+package ca.uhn.fhir.fhirpath;
 
 /*
  * #%L
@@ -23,18 +23,18 @@ package ca.uhn.fhir.fluentpath;
 import ca.uhn.fhir.rest.server.exceptions.InternalErrorException;
 
 /**
- * This exception is thrown if a FluentPath expression can not be executed successfully
+ * This exception is thrown if a FHIRPath expression can not be executed successfully
  * for any reason
  */
-public class FluentPathExecutionException extends InternalErrorException {
+public class FhirPathExecutionException extends InternalErrorException {
 
 	private static final long serialVersionUID = 1L;
 
-	public FluentPathExecutionException(Throwable theCause) {
+	public FhirPathExecutionException(Throwable theCause) {
 		super(theCause);
 	}
 
-	public FluentPathExecutionException(String theMessage) {
+	public FhirPathExecutionException(String theMessage) {
 		super(theMessage);
 	}
 

hapi-fhir-base/src/main/java/ca/uhn/fhir/fhirpath/IFhirPath.java

@@ -1,4 +1,4 @@
-package ca.uhn.fhir.fluentpath;
+package ca.uhn.fhir.fhirpath;
 
 /*
  * #%L
@@ -25,7 +25,7 @@ import java.util.Optional;
 
 import org.hl7.fhir.instance.model.api.IBase;
 
-public interface IFluentPath {
+public interface IFhirPath {
 
 	/**
 	 * Apply the given FluentPath expression against the given input and return

hapi-fhir-base/src/main/java/ca/uhn/fhir/model/api/IFhirVersion.java

@@ -23,10 +23,10 @@ package ca.uhn.fhir.model.api;
 import java.io.InputStream;
 import java.util.Date;
 
+import ca.uhn.fhir.fhirpath.IFhirPath;
 import org.hl7.fhir.instance.model.api.*;
 
 import ca.uhn.fhir.context.*;
-import ca.uhn.fhir.fluentpath.IFluentPath;
 import ca.uhn.fhir.rest.api.IVersionSpecificBundleFactory;
 
 /**
@@ -38,7 +38,7 @@ import ca.uhn.fhir.rest.api.IVersionSpecificBundleFactory;
  */
 public interface IFhirVersion {
 
-	IFluentPath createFluentPathExecutor(FhirContext theFhirContext);
+	IFhirPath createFluentPathExecutor(FhirContext theFhirContext);
 
 	IBaseResource generateProfile(RuntimeResourceDefinition theRuntimeResourceDefinition, String theServerBase);
 

hapi-fhir-base/src/main/java/ca/uhn/fhir/narrative2/BaseNarrativeGenerator.java

@@ -24,7 +24,7 @@ import ca.uhn.fhir.context.BaseRuntimeChildDefinition;
 import ca.uhn.fhir.context.BaseRuntimeElementCompositeDefinition;
 import ca.uhn.fhir.context.FhirContext;
 import ca.uhn.fhir.context.FhirVersionEnum;
-import ca.uhn.fhir.fluentpath.IFluentPath;
+import ca.uhn.fhir.fhirpath.IFhirPath;
 import ca.uhn.fhir.narrative.INarrativeGenerator;
 import ca.uhn.fhir.rest.server.exceptions.InternalErrorException;
 import org.hl7.fhir.instance.model.api.IBase;
@@ -120,7 +120,7 @@ public abstract class BaseNarrativeGenerator implements INarrativeGenerator {
 		if (theFhirContext.getVersion().getVersion().isOlderThan(FhirVersionEnum.DSTU3)) {
 			return Collections.singletonList(theResource);
 		}
-		IFluentPath fhirPath = theFhirContext.newFluentPath();
+		IFhirPath fhirPath = theFhirContext.newFluentPath();
 		return fhirPath.evaluate(theResource, theContextPath, IBase.class);
 	}
 

hapi-fhir-base/src/main/java/ca/uhn/fhir/rest/api/Constants.java

@@ -259,6 +259,7 @@ public class Constants {
 	 * </p>
 	 */
 	public static final String EXT_META_SOURCE = "http://hapifhir.io/fhir/StructureDefinition/resource-meta-source";
+	public static final String PARAM_FHIRPATH = "_fhirpath";
 
 	static {
 		CHARSET_UTF8 = StandardCharsets.UTF_8;

hapi-fhir-base/src/main/java/ca/uhn/fhir/util/ParametersUtil.java

@@ -238,7 +238,7 @@ public class ParametersUtil {
 		addPart(theContext, theParameter, theName, coding);
 	}
 
-	private static void addPart(FhirContext theContext, IBase theParameter, String theName, IBase theValue) {
+	public static void addPart(FhirContext theContext, IBase theParameter, String theName, IBase theValue) {
 		BaseRuntimeElementCompositeDefinition<?> def = (BaseRuntimeElementCompositeDefinition<?>) theContext.getElementDefinition(theParameter.getClass());
 		BaseRuntimeChildDefinition partChild = def.getChildByName("part");
 
@@ -252,4 +252,19 @@ public class ParametersUtil {
 
 		partChildElem.getChildByName("value[x]").getMutator().addValue(part, theValue);
 	}
+
+	public static void addPartResource(FhirContext theContext, IBase theParameter, String theName, IBaseResource theValue) {
+		BaseRuntimeElementCompositeDefinition<?> def = (BaseRuntimeElementCompositeDefinition<?>) theContext.getElementDefinition(theParameter.getClass());
+		BaseRuntimeChildDefinition partChild = def.getChildByName("part");
+
+		BaseRuntimeElementCompositeDefinition<?> partChildElem = (BaseRuntimeElementCompositeDefinition<?>) partChild.getChildByName("part");
+		IBase part = partChildElem.newInstance();
+		partChild.getMutator().addValue(theParameter, part);
+
+		IPrimitiveType<String> name = (IPrimitiveType<String>) theContext.getElementDefinition("string").newInstance();
+		name.setValue(theName);
+		partChildElem.getChildByName("name").getMutator().addValue(part, name);
+
+		partChildElem.getChildByName("resource").getMutator().addValue(part, theValue);
+	}
 }

hapi-fhir-docs/src/main/java/ca/uhn/hapi/fhir/docs/ServletExamples.java

@@ -32,11 +32,11 @@ import javax.servlet.ServletException;
 import javax.servlet.annotation.WebServlet;
 import java.util.Arrays;
 
-@SuppressWarnings("serial")
+@SuppressWarnings({"serial", "RedundantThrows", "InnerClassMayBeStatic"})
 public class ServletExamples {
 
    // START SNIPPET: loggingInterceptor
-   @WebServlet(urlPatterns = { "/fhir/*" }, displayName = "FHIR Server")
+	@WebServlet(urlPatterns = { "/fhir/*" }, displayName = "FHIR Server")
    public class RestfulServerWithLogging extends RestfulServer {
 
       @Override
@@ -121,6 +121,24 @@ public class ServletExamples {
    }
    // END SNIPPET: exceptionInterceptor
 
+	// START SNIPPET: fhirPathInterceptor
+	@WebServlet(urlPatterns = { "/fhir/*" }, displayName = "FHIR Server")
+	public class RestfulServerWithFhirPath extends RestfulServer {
+
+		@Override
+		protected void initialize() throws ServletException {
+
+			// ... define your resource providers here ...
+
+			// Now register the interceptor
+			FhirPathFilterInterceptor interceptor = new FhirPathFilterInterceptor();
+			registerInterceptor(interceptor);
+
+		}
+
+	}
+	// END SNIPPET: fhirPathInterceptor
+
    // START SNIPPET: responseHighlighterInterceptor
    @WebServlet(urlPatterns = { "/fhir/*" }, displayName = "FHIR Server")
    public class RestfulServerWithResponseHighlighter extends RestfulServer {

hapi-fhir-docs/src/main/resources/ca/uhn/hapi/fhir/changelog/4_3_0/1769-add-fhirpath-interceptor.yaml

@@ -0,0 +1,6 @@
+---
+type: add
+issue: 1769
+title: A new built-in server interceptor called FhirPathFilterInterceptor has been added. This interceptor
+   evaluates an arbitrary FHIRPath expression against the resource being returned and replaces the response
+   with a Parameters resource containing the results of the evaluation.

hapi-fhir-docs/src/main/resources/ca/uhn/hapi/fhir/changelog/4_3_0/changes.yaml

@@ -17,3 +17,11 @@
     [Migrating to HAPI FHIR 5.x](/hapi-fhir/docs/validation/instance_validator.html#migrating-to-hapi-fhir-5x)
     for details on how to account for this change in your code.
     "
+- item:
+     issue: "1769"
+     type: "change"
+     title: "**Breaking Change**:
+    The `IFluentPath` interface has been renamed to `IFhirPath`, and the `FhirContext#newFluentPath()` method
+    has been replaced with an equivalent `FhirContext.newFhirPath()`. The FhirPath expression language was initially
+    called FluentPath before being renamed, so this change brings HAPI FHIR inline with the correct naming.
+    "

hapi-fhir-docs/src/main/resources/ca/uhn/hapi/fhir/docs/interceptors/built_in_server_interceptors.md

@@ -50,6 +50,52 @@ The following example shows how to register the ExceptionHandlingInterceptor.
 {{snippet:classpath:/ca/uhn/hapi/fhir/docs/ServletExamples.java|exceptionInterceptor}}
 ```
 
+# Response Customizing: Evaluate FHIRPath
+
+The FhirPathFilterInterceptor looks for a request URL parameter in the form `_fhirpath=(expression)` in all REST requests. If this parameter is found, the value is treated as a [FHIRPath](http://hl7.org/fhirpath/) expression. The response resource will be replaced with a [Parameters](hl7.org/fhir/parameters.html) resource containing the results of the given expression applied against the response resource.   
+
+* [FhirPathFilterInterceptor JavaDoc](/apidocs/hapi-fhir-server/ca/uhn/fhir/rest/server/interceptor/FhirPathFilterInterceptor.html)
+* [FhirPathFilterInterceptor Source](https://github.com/jamesagnew/hapi-fhir/blob/master/hapi-fhir-server/src/main/java/ca/uhn/fhir/rest/server/interceptor/FhirPathFilterInterceptor.java)
+
+The following example shows how to register the ExceptionHandlingInterceptor.
+
+```java
+{{snippet:classpath:/ca/uhn/hapi/fhir/docs/ServletExamples.java|exceptionInterceptor}}
+```
+
+An example URL to invoke this function is shown below:
+
+```url
+https://hapi.fhir.org/baseR4/Patient?_fhirpath=Bundle.entry.resource.as(Patient).name&_pretty=true
+```
+
+A sample response to this query is shown below:
+
+```json
+{
+  "resourceType": "Parameters",
+  "parameter": [ {
+    "name": "result",
+    "part": [ {
+      "name": "expression",
+      "valueString": "Bundle.entry.resource.as(Patient).name"
+    }, {
+      "name": "result",
+      "valueHumanName": {
+        "family": "Simpson",
+        "given": [ "Homer", "Jay" ]
+      }
+    }, {
+      "name": "result",
+      "valueHumanName": {
+        "family": "Simpson",
+        "given": [ "Grandpa" ]
+      }
+    } ]
+  } ]
+}
+```
+
 # Validation: Request and Response Validation
 
 HAPI FHIR provides a pair of interceptors that can be used to validate incoming requests received by the server, as well as outgoing responses generated by the server.

hapi-fhir-jpaserver-uhnfhirtest/src/main/java/ca/uhn/fhirtest/TestRestfulServer.java

@@ -28,6 +28,7 @@ import ca.uhn.fhir.rest.server.HardcodedServerAddressStrategy;
 import ca.uhn.fhir.rest.server.RestfulServer;
 import ca.uhn.fhir.rest.server.interceptor.BanUnsupportedHttpMethodsInterceptor;
 import ca.uhn.fhir.rest.server.interceptor.CorsInterceptor;
+import ca.uhn.fhir.rest.server.interceptor.FhirPathFilterInterceptor;
 import ca.uhn.fhir.rest.server.interceptor.ResponseHighlighterInterceptor;
 import ca.uhn.fhirtest.config.TestDstu2Config;
 import ca.uhn.fhirtest.config.TestDstu3Config;
@@ -198,6 +199,11 @@ public class TestRestfulServer extends RestfulServer {
 		CorsInterceptor corsInterceptor = new CorsInterceptor();
 		registerInterceptor(corsInterceptor);
 
+		/*
+		 * Enable FHIRPath evaluation
+		 */
+		registerInterceptor(new FhirPathFilterInterceptor());
+
 		/*
 		 * Enable version conversion
 		 */

hapi-fhir-server/src/main/java/ca/uhn/fhir/rest/server/interceptor/FhirPathFilterInterceptor.java

@@ -0,0 +1,70 @@
+package ca.uhn.fhir.rest.server.interceptor;
+
+import ca.uhn.fhir.context.FhirContext;
+import ca.uhn.fhir.fhirpath.FhirPathExecutionException;
+import ca.uhn.fhir.fhirpath.IFhirPath;
+import ca.uhn.fhir.interceptor.api.Hook;
+import ca.uhn.fhir.interceptor.api.Pointcut;
+import ca.uhn.fhir.rest.api.Constants;
+import ca.uhn.fhir.rest.api.server.RequestDetails;
+import ca.uhn.fhir.rest.api.server.ResponseDetails;
+import ca.uhn.fhir.rest.server.exceptions.InvalidRequestException;
+import ca.uhn.fhir.util.ParametersUtil;
+import org.hl7.fhir.instance.model.api.IBase;
+import org.hl7.fhir.instance.model.api.IBaseParameters;
+import org.hl7.fhir.instance.model.api.IBaseResource;
+
+import java.util.List;
+
+import static org.apache.commons.lang3.StringUtils.isNotBlank;
+
+/**
+ * This interceptor looks for a URL parameter on requests called <code>_fhirpath</code> and
+ * replaces the resource being returned with a Parameters resource containing the results of
+ * the given FHIRPath expression evaluated against the resource that would otherwise
+ * have been returned.
+ *
+ * @see <a href="https://hapifhir.io/hapi-fhir/docs/interceptors/built_in_server_interceptors.html#response-customizing-evaluate-fhirpath">Interceptors - Response Customization: Evaluate FHIRPath</a>
+ * @since 5.0.0
+ */
+public class FhirPathFilterInterceptor {
+
+	@Hook(Pointcut.SERVER_OUTGOING_RESPONSE)
+	public void preProcessOutgoingResponse(RequestDetails theRequestDetails, ResponseDetails theResponseDetails) {
+		IBaseResource responseResource = theResponseDetails.getResponseResource();
+		if (responseResource != null) {
+			String[] fhirPathParams = theRequestDetails.getParameters().get(Constants.PARAM_FHIRPATH);
+			if (fhirPathParams != null) {
+
+				FhirContext ctx = theRequestDetails.getFhirContext();
+				IBaseParameters responseParameters = ParametersUtil.newInstance(ctx);
+
+				for (String expression : fhirPathParams) {
+					if (isNotBlank(expression)) {
+						IBase resultPart = ParametersUtil.addParameterToParameters(ctx, responseParameters, "result");
+						ParametersUtil.addPartString(ctx, resultPart, "expression", expression);
+
+						IFhirPath fhirPath = ctx.newFhirPath();
+						List<IBase> outputs;
+						try {
+							outputs = fhirPath.evaluate(responseResource, expression, IBase.class);
+						} catch (FhirPathExecutionException e) {
+							throw new InvalidRequestException("Error parsing FHIRPath expression: " + e.getMessage());
+						}
+
+						for (IBase nextOutput : outputs) {
+							if (nextOutput instanceof IBaseResource) {
+								ParametersUtil.addPartResource(ctx, resultPart, "result", (IBaseResource) nextOutput);
+							} else {
+								ParametersUtil.addPart(ctx, resultPart, "result", nextOutput);
+							}
+						}
+					}
+				}
+
+				theResponseDetails.setResponseResource(responseParameters);
+			}
+		}
+	}
+
+}

hapi-fhir-structures-dstu/src/main/java/ca/uhn/fhir/model/dstu/FhirDstu1.java

@@ -60,7 +60,7 @@ import ca.uhn.fhir.context.RuntimePrimitiveDatatypeDefinition;
 import ca.uhn.fhir.context.RuntimeResourceBlockDefinition;
 import ca.uhn.fhir.context.RuntimeResourceDefinition;
 import ca.uhn.fhir.context.support.IContextValidationSupport;
-import ca.uhn.fhir.fluentpath.IFluentPath;
+import ca.uhn.fhir.fhirpath.IFluentPath;
 import ca.uhn.fhir.model.api.ICompositeDatatype;
 import ca.uhn.fhir.model.api.IFhirVersion;
 import ca.uhn.fhir.model.api.IPrimitiveDatatype;

hapi-fhir-structures-dstu2.1/src/main/java/org/hl7/fhir/dstu2016may/hapi/ctx/FhirDstu2_1.java

@@ -30,7 +30,7 @@ import org.hl7.fhir.dstu2016may.model.*;
 import org.hl7.fhir.instance.model.api.*;
 
 import ca.uhn.fhir.context.*;
-import ca.uhn.fhir.fluentpath.IFluentPath;
+import ca.uhn.fhir.fhirpath.IFhirPath;
 import ca.uhn.fhir.model.api.IFhirVersion;
 import ca.uhn.fhir.model.primitive.IdDt;
 import ca.uhn.fhir.rest.api.IVersionSpecificBundleFactory;
@@ -41,7 +41,7 @@ public class FhirDstu2_1 implements IFhirVersion {
 	private String myId;
 
 	@Override
-	public IFluentPath createFluentPathExecutor(FhirContext theFhirContext) {
+	public IFhirPath createFluentPathExecutor(FhirContext theFhirContext) {
 		throw new UnsupportedOperationException("FluentPath is not supported in DSTU2 contexts");
 	}
 

hapi-fhir-structures-dstu2/src/main/java/ca/uhn/fhir/model/dstu2/FhirDstu2.java

@@ -23,11 +23,11 @@ package ca.uhn.fhir.model.dstu2;
 import java.io.InputStream;
 import java.util.Date;
 
+import ca.uhn.fhir.fhirpath.IFhirPath;
 import org.apache.commons.lang3.StringUtils;
 import org.hl7.fhir.instance.model.api.*;
 
 import ca.uhn.fhir.context.*;
-import ca.uhn.fhir.fluentpath.IFluentPath;
 import ca.uhn.fhir.model.api.*;
 import ca.uhn.fhir.model.base.composite.*;
 import ca.uhn.fhir.model.dstu2.composite.*;
@@ -42,7 +42,7 @@ public class FhirDstu2 implements IFhirVersion {
 	private String myId;
 
 	@Override
-	public IFluentPath createFluentPathExecutor(FhirContext theFhirContext) {
+	public IFhirPath createFluentPathExecutor(FhirContext theFhirContext) {
 		throw new UnsupportedOperationException("FluentPath is not supported in DSTU2 contexts");
 	}
 

hapi-fhir-structures-dstu3/src/main/java/org/hl7/fhir/dstu3/hapi/ctx/FhirDstu3.java

@@ -24,13 +24,13 @@ import ca.uhn.fhir.context.ConfigurationException;
 import ca.uhn.fhir.context.FhirContext;
 import ca.uhn.fhir.context.FhirVersionEnum;
 import ca.uhn.fhir.context.RuntimeResourceDefinition;
-import ca.uhn.fhir.fluentpath.IFluentPath;
+import ca.uhn.fhir.fhirpath.IFhirPath;
 import ca.uhn.fhir.model.api.IFhirVersion;
 import ca.uhn.fhir.model.primitive.IdDt;
 import ca.uhn.fhir.rest.api.IVersionSpecificBundleFactory;
 import ca.uhn.fhir.util.ReflectionUtil;
 import org.apache.commons.lang3.StringUtils;
-import org.hl7.fhir.dstu3.hapi.fluentpath.FluentPathDstu3;
+import org.hl7.fhir.dstu3.hapi.fluentpath.FhirPathDstu3;
 import org.hl7.fhir.dstu3.hapi.rest.server.Dstu3BundleFactory;
 import org.hl7.fhir.dstu3.model.*;
 import org.hl7.fhir.instance.model.api.*;
@@ -44,8 +44,8 @@ public class FhirDstu3 implements IFhirVersion {
   private String myId;
 
   @Override
-  public IFluentPath createFluentPathExecutor(FhirContext theFhirContext) {
+  public IFhirPath createFluentPathExecutor(FhirContext theFhirContext) {
-    return new FluentPathDstu3(theFhirContext);
+    return new FhirPathDstu3(theFhirContext);
   }
 
   @Override

hapi-fhir-structures-dstu3/src/main/java/org/hl7/fhir/dstu3/hapi/fluentpath/FhirPathDstu3.java

@@ -2,8 +2,8 @@ package org.hl7.fhir.dstu3.hapi.fluentpath;
 
 import ca.uhn.fhir.context.FhirContext;
 import ca.uhn.fhir.context.support.IValidationSupport;
-import ca.uhn.fhir.fluentpath.FluentPathExecutionException;
+import ca.uhn.fhir.fhirpath.FhirPathExecutionException;
-import ca.uhn.fhir.fluentpath.IFluentPath;
+import ca.uhn.fhir.fhirpath.IFhirPath;
 import org.hl7.fhir.dstu3.hapi.ctx.HapiWorkerContext;
 import org.hl7.fhir.dstu3.model.Base;
 import org.hl7.fhir.dstu3.utils.FHIRPathEngine;
@@ -13,11 +13,11 @@ import org.hl7.fhir.instance.model.api.IBase;
 import java.util.List;
 import java.util.Optional;
 
-public class FluentPathDstu3 implements IFluentPath {
+public class FhirPathDstu3 implements IFhirPath {
 
 	private FHIRPathEngine myEngine;
 
-	public FluentPathDstu3(FhirContext theCtx) {
+	public FhirPathDstu3(FhirContext theCtx) {
      IValidationSupport validationSupport = theCtx.getValidationSupport();
 		myEngine = new FHIRPathEngine(new HapiWorkerContext(theCtx, validationSupport));
 	}
@@ -29,12 +29,12 @@ public class FluentPathDstu3 implements IFluentPath {
 		try {
 			result = myEngine.evaluate((Base)theInput, thePath);
 		} catch (FHIRException e) {
-			throw new FluentPathExecutionException(e);
+			throw new FhirPathExecutionException(e);
 		}
 
 		for (Base next : result) {
 			if (!theReturnType.isAssignableFrom(next.getClass())) {
-				throw new FluentPathExecutionException("FluentPath expression \"" + thePath + "\" returned unexpected type " + next.getClass().getSimpleName() + " - Expected " + theReturnType.getName());
+				throw new FhirPathExecutionException("FluentPath expression \"" + thePath + "\" returned unexpected type " + next.getClass().getSimpleName() + " - Expected " + theReturnType.getName());
 			}
 		}
 		

hapi-fhir-structures-hl7org-dstu2/src/main/java/org/hl7/fhir/dstu2/hapi/ctx/FhirDstu2Hl7Org.java

@@ -24,12 +24,12 @@ import java.io.InputStream;
 import java.util.ArrayList;
 import java.util.Date;
 
+import ca.uhn.fhir.fhirpath.IFhirPath;
 import org.apache.commons.lang3.StringUtils;
 import org.hl7.fhir.dstu2.model.*;
 import org.hl7.fhir.instance.model.api.*;
 
 import ca.uhn.fhir.context.*;
-import ca.uhn.fhir.fluentpath.IFluentPath;
 import ca.uhn.fhir.model.api.IFhirVersion;
 import ca.uhn.fhir.model.base.composite.BaseCodingDt;
 import ca.uhn.fhir.rest.api.IVersionSpecificBundleFactory;
@@ -41,7 +41,7 @@ public class FhirDstu2Hl7Org implements IFhirVersion {
   private String myId;
 
   @Override
-  public IFluentPath createFluentPathExecutor(FhirContext theFhirContext) {
+  public IFhirPath createFluentPathExecutor(FhirContext theFhirContext) {
     throw new UnsupportedOperationException("FluentPath is not supported in DSTU2 contexts");
   }
 

hapi-fhir-structures-r4/src/main/java/org/hl7/fhir/r4/hapi/ctx/FhirR4.java

@@ -26,12 +26,12 @@ import java.util.List;
 
 import org.apache.commons.lang3.StringUtils;
 import org.hl7.fhir.instance.model.api.*;
-import org.hl7.fhir.r4.hapi.fluentpath.FluentPathR4;
+import org.hl7.fhir.r4.hapi.fluentpath.FhirPathR4;
 import org.hl7.fhir.r4.hapi.rest.server.R4BundleFactory;
 import org.hl7.fhir.r4.model.*;
 
 import ca.uhn.fhir.context.*;
-import ca.uhn.fhir.fluentpath.IFluentPath;
+import ca.uhn.fhir.fhirpath.IFhirPath;
 import ca.uhn.fhir.model.api.IFhirVersion;
 import ca.uhn.fhir.model.primitive.IdDt;
 import ca.uhn.fhir.rest.api.IVersionSpecificBundleFactory;
@@ -42,8 +42,8 @@ public class FhirR4 implements IFhirVersion {
 	private String myId;
 
 	@Override
-	public IFluentPath createFluentPathExecutor(FhirContext theFhirContext) {
+	public IFhirPath createFluentPathExecutor(FhirContext theFhirContext) {
-		return new FluentPathR4(theFhirContext);
+		return new FhirPathR4(theFhirContext);
 	}
 
 	@Override

hapi-fhir-structures-r4/src/main/java/org/hl7/fhir/r4/hapi/fluentpath/FhirPathR4.java

@@ -2,8 +2,8 @@ package org.hl7.fhir.r4.hapi.fluentpath;
 
 import ca.uhn.fhir.context.FhirContext;
 import ca.uhn.fhir.context.support.IValidationSupport;
-import ca.uhn.fhir.fluentpath.FluentPathExecutionException;
+import ca.uhn.fhir.fhirpath.FhirPathExecutionException;
-import ca.uhn.fhir.fluentpath.IFluentPath;
+import ca.uhn.fhir.fhirpath.IFhirPath;
 import org.hl7.fhir.exceptions.FHIRException;
 import org.hl7.fhir.instance.model.api.IBase;
 import org.hl7.fhir.r4.hapi.ctx.HapiWorkerContext;
@@ -13,11 +13,11 @@ import org.hl7.fhir.r4.utils.FHIRPathEngine;
 import java.util.List;
 import java.util.Optional;
 
-public class FluentPathR4 implements IFluentPath {
+public class FhirPathR4 implements IFhirPath {
 
   private FHIRPathEngine myEngine;
 
-  public FluentPathR4(FhirContext theCtx) {
+  public FhirPathR4(FhirContext theCtx) {
     IValidationSupport validationSupport = theCtx.getValidationSupport();
     myEngine = new FHIRPathEngine(new HapiWorkerContext(theCtx, validationSupport));
   }
@@ -29,12 +29,12 @@ public class FluentPathR4 implements IFluentPath {
     try {
       result = myEngine.evaluate((Base) theInput, thePath);
     } catch (FHIRException e) {
-      throw new FluentPathExecutionException(e);
+      throw new FhirPathExecutionException(e);
     }
 
     for (Base next : result) {
       if (!theReturnType.isAssignableFrom(next.getClass())) {
-        throw new FluentPathExecutionException("FluentPath expression \"" + thePath + "\" returned unexpected type " + next.getClass().getSimpleName() + " - Expected " + theReturnType.getName());
+        throw new FhirPathExecutionException("FluentPath expression \"" + thePath + "\" returned unexpected type " + next.getClass().getSimpleName() + " - Expected " + theReturnType.getName());
       }
     }
 

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

@@ -0,0 +1,170 @@
+package ca.uhn.fhir.rest.server.interceptor;
+
+import ca.uhn.fhir.context.FhirContext;
+import ca.uhn.fhir.rest.api.Constants;
+import ca.uhn.fhir.rest.client.api.IGenericClient;
+import ca.uhn.fhir.test.utilities.HttpClientRule;
+import ca.uhn.fhir.test.utilities.server.HashMapResourceProviderRule;
+import ca.uhn.fhir.test.utilities.server.RestfulServerRule;
+import ca.uhn.fhir.util.UrlUtil;
+import com.google.common.base.Charsets;
+import org.apache.commons.io.IOUtils;
+import org.apache.http.client.methods.CloseableHttpResponse;
+import org.apache.http.client.methods.HttpGet;
+import org.apache.http.impl.client.CloseableHttpClient;
+import org.hl7.fhir.instance.model.api.IIdType;
+import org.hl7.fhir.r4.model.Patient;
+import org.junit.Before;
+import org.junit.ClassRule;
+import org.junit.Test;
+import org.slf4j.Logger;
+import org.slf4j.LoggerFactory;
+
+import java.io.IOException;
+
+import static org.hamcrest.Matchers.containsString;
+import static org.hamcrest.Matchers.not;
+import static org.junit.Assert.assertEquals;
+import static org.junit.Assert.assertThat;
+
+public class FhirPathFilterInterceptorTest {
+
+	private static final Logger ourLog = LoggerFactory.getLogger(FhirPathFilterInterceptorTest.class);
+	@ClassRule
+	public static HttpClientRule ourClientRule = new HttpClientRule();
+	private static FhirContext ourCtx = FhirContext.forR4();
+	@ClassRule
+	public static RestfulServerRule ourServerRule = new RestfulServerRule(ourCtx);
+	@ClassRule
+	public static HashMapResourceProviderRule<Patient> ourProviderRule = new HashMapResourceProviderRule<>(ourServerRule, Patient.class);
+	private IGenericClient myClient;
+	private String myBaseUrl;
+	private CloseableHttpClient myHttpClient;
+	private IIdType myPatientId;
+
+	@Before
+	public void before() {
+		ourProviderRule.clear();
+		ourServerRule.getRestfulServer().getInterceptorService().unregisterAllInterceptors();
+		ourServerRule.getRestfulServer().getInterceptorService().registerInterceptor(new FhirPathFilterInterceptor());
+
+		myClient = ourServerRule.getFhirClient();
+		myBaseUrl = "http://localhost:" + ourServerRule.getPort();
+		myHttpClient = ourClientRule.getClient();
+	}
+
+	@Test
+	public void testUnfilteredResponse() throws IOException {
+		createPatient();
+
+		HttpGet request = new HttpGet(myPatientId.getValue());
+		try (CloseableHttpResponse response = myHttpClient.execute(request)) {
+			String responseText = IOUtils.toString(response.getEntity().getContent(), Charsets.UTF_8);
+			ourLog.info("Response:\n{}", responseText);
+			assertThat(responseText, containsString("\"system\": \"http://identifiers/1\""));
+			assertThat(responseText, containsString("\"given\": [ \"Homer\", \"Jay\" ]"));
+		}
+	}
+
+
+	@Test
+	public void testUnfilteredResponse_WithResponseHighlightingInterceptor() throws IOException {
+		ourServerRule.getRestfulServer().registerInterceptor(new ResponseHighlighterInterceptor());
+		createPatient();
+
+		HttpGet request = new HttpGet(myPatientId.getValue() + "?_format=" + Constants.FORMATS_HTML_JSON);
+		try (CloseableHttpResponse response = myHttpClient.execute(request)) {
+			String responseText = IOUtils.toString(response.getEntity().getContent(), Charsets.UTF_8);
+			ourLog.info("Response:\n{}", responseText);
+			assertThat(responseText, containsString("<span class='hlTagName'>&quot;system&quot;</span>: <span class='hlQuot'>&quot;http://identifiers/1&quot;"));
+			assertThat(responseText, containsString("<span class='hlTagName'>&quot;given&quot;</span>: <span class='hlControl'>[</span> <span class='hlTagName'>&quot;Homer&quot;</span><span class='hlControl'>,</span> <span class='hlTagName'>&quot;Jay&quot;</span> ]</div>"));
+		}
+	}
+
+	@Test
+	public void testFilteredResponse() throws IOException {
+		createPatient();
+
+		HttpGet request = new HttpGet(myPatientId + "?_fhirpath=Patient.identifier&_pretty=true");
+		try (CloseableHttpResponse response = myHttpClient.execute(request)) {
+			String responseText = IOUtils.toString(response.getEntity().getContent(), Charsets.UTF_8);
+			ourLog.info("Response:\n{}", responseText);
+			assertThat(responseText, containsString("\"system\": \"http://identifiers/1\""));
+			assertThat(responseText, not(containsString("\"given\": [ \"Homer\", \"Jay\" ]")));
+		}
+
+	}
+
+	@Test
+	public void testFilteredResponse_ExpressionReturnsResource() throws IOException {
+		createPatient();
+
+		HttpGet request = new HttpGet(myPatientId + "?_fhirpath=Patient&_pretty=true");
+		try (CloseableHttpResponse response = myHttpClient.execute(request)) {
+			String responseText = IOUtils.toString(response.getEntity().getContent(), Charsets.UTF_8);
+			ourLog.info("Response:\n{}", responseText);
+			assertThat(responseText, containsString("\"resource\": {"));
+			assertThat(responseText, containsString("\"system\": \"http://identifiers/1\""));
+			assertThat(responseText, containsString("\"given\": [ \"Homer\", \"Jay\" ]"));
+		}
+
+	}
+
+	@Test
+	public void testFilteredResponse_ExpressionIsInvalid() throws IOException {
+		createPatient();
+
+		HttpGet request = new HttpGet(myPatientId + "?_fhirpath=" + UrlUtil.escapeUrlParam("***"));
+		try (CloseableHttpResponse response = myHttpClient.execute(request)) {
+			String responseText = IOUtils.toString(response.getEntity().getContent(), Charsets.UTF_8);
+			ourLog.info("Response:\n{}", responseText);
+			assertEquals(400, response.getStatusLine().getStatusCode());
+			assertThat(responseText, containsString("Error parsing FHIRPath expression: Error performing *: left operand has more than one value"));
+		}
+
+	}
+
+	@Test
+	public void testFilteredResponseBundle() throws IOException {
+		createPatient();
+
+		HttpGet request = new HttpGet(myBaseUrl + "/Patient?_fhirpath=Bundle.entry.resource.as(Patient).name&_pretty=true");
+		try (CloseableHttpResponse response = myHttpClient.execute(request)) {
+			String responseText = IOUtils.toString(response.getEntity().getContent(), Charsets.UTF_8);
+			ourLog.info("Response:\n{}", responseText);
+			assertThat(responseText, containsString(
+				"      \"valueHumanName\": {\n" +
+					"        \"family\": \"Simpson\",\n" +
+					"        \"given\": [ \"Homer\", \"Jay\" ]\n" +
+					"      }"
+			));
+		}
+
+	}
+
+	@Test
+	public void testFilteredResponse_WithResponseHighlightingInterceptor() throws IOException {
+		ourServerRule.getRestfulServer().registerInterceptor(new ResponseHighlighterInterceptor());
+		createPatient();
+
+		HttpGet request = new HttpGet(myPatientId + "?_fhirpath=Patient.identifier&_format=" + Constants.FORMATS_HTML_JSON);
+		try (CloseableHttpResponse response = myHttpClient.execute(request)) {
+			String responseText = IOUtils.toString(response.getEntity().getContent(), Charsets.UTF_8);
+			ourLog.info("Response:\n{}", responseText);
+			assertThat(responseText, containsString("<span class='hlTagName'>&quot;system&quot;</span>: <span class='hlQuot'>&quot;http://identifiers/1&quot;"));
+			assertThat(responseText, not(containsString("<span class='hlTagName'>&quot;given&quot;</span>: <span class='hlControl'>[</span> <span class='hlTagName'>&quot;Homer&quot;</span><span class='hlControl'>,</span> <span class='hlTagName'>&quot;Jay&quot;</span> ]</div>")));
+		}
+
+	}
+
+	private void createPatient() {
+		Patient p = new Patient();
+		p.setActive(true);
+		p.addIdentifier().setSystem("http://identifiers/1").setValue("value-1");
+		p.addIdentifier().setSystem("http://identifiers/2").setValue("value-2");
+		p.addName().setFamily("Simpson").addGiven("Homer").addGiven("Jay");
+		p.addName().setFamily("Simpson").addGiven("Grandpa");
+		myPatientId = myClient.create().resource(p).execute().getId().withServerBase(myBaseUrl, "Patient");
+	}
+
+}

hapi-fhir-structures-r5/src/main/java/org/hl7/fhir/r5/hapi/ctx/FhirR5.java

@@ -24,7 +24,7 @@ import ca.uhn.fhir.context.ConfigurationException;
 import ca.uhn.fhir.context.FhirContext;
 import ca.uhn.fhir.context.FhirVersionEnum;
 import ca.uhn.fhir.context.RuntimeResourceDefinition;
-import ca.uhn.fhir.fluentpath.IFluentPath;
+import ca.uhn.fhir.fhirpath.IFhirPath;
 import ca.uhn.fhir.model.api.IFhirVersion;
 import ca.uhn.fhir.model.primitive.IdDt;
 import ca.uhn.fhir.rest.api.IVersionSpecificBundleFactory;
@@ -52,7 +52,7 @@ public class FhirR5 implements IFhirVersion {
 	private String myId;
 
 	@Override
-	public IFluentPath createFluentPathExecutor(FhirContext theFhirContext) {
+	public IFhirPath createFluentPathExecutor(FhirContext theFhirContext) {
 		return new FhirPathR5(theFhirContext);
 	}
 

hapi-fhir-structures-r5/src/main/java/org/hl7/fhir/r5/hapi/fhirpath/FhirPathR5.java

@@ -2,8 +2,8 @@ package org.hl7.fhir.r5.hapi.fhirpath;
 
 import ca.uhn.fhir.context.FhirContext;
 import ca.uhn.fhir.context.support.IValidationSupport;
-import ca.uhn.fhir.fluentpath.FluentPathExecutionException;
+import ca.uhn.fhir.fhirpath.FhirPathExecutionException;
-import ca.uhn.fhir.fluentpath.IFluentPath;
+import ca.uhn.fhir.fhirpath.IFhirPath;
 import org.hl7.fhir.exceptions.FHIRException;
 import org.hl7.fhir.instance.model.api.IBase;
 import org.hl7.fhir.r5.hapi.ctx.HapiWorkerContext;
@@ -13,7 +13,7 @@ import org.hl7.fhir.r5.utils.FHIRPathEngine;
 import java.util.List;
 import java.util.Optional;
 
-public class FhirPathR5 implements IFluentPath {
+public class FhirPathR5 implements IFhirPath {
 
   private FHIRPathEngine myEngine;
 
@@ -29,12 +29,12 @@ public class FhirPathR5 implements IFluentPath {
     try {
       result = myEngine.evaluate((Base) theInput, thePath);
     } catch (FHIRException e) {
-      throw new FluentPathExecutionException(e);
+      throw new FhirPathExecutionException(e);
     }
 
     for (Base next : result) {
       if (!theReturnType.isAssignableFrom(next.getClass())) {
-        throw new FluentPathExecutionException("FluentPath expression \"" + thePath + "\" returned unexpected type " + next.getClass().getSimpleName() + " - Expected " + theReturnType.getName());
+        throw new FhirPathExecutionException("FluentPath expression \"" + thePath + "\" returned unexpected type " + next.getClass().getSimpleName() + " - Expected " + theReturnType.getName());
       }
     }
 

hapi-fhir-test-utilities/src/main/java/ca/uhn/fhir/test/utilities/HttpClientRule.java

@@ -0,0 +1,58 @@
+package ca.uhn.fhir.test.utilities;
+
+/*-
+ * #%L
+ * HAPI FHIR Test Utilities
+ * %%
+ * Copyright (C) 2014 - 2020 University Health Network
+ * %%
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ * #L%
+ */
+
+import org.apache.http.impl.client.CloseableHttpClient;
+import org.apache.http.impl.client.HttpClientBuilder;
+import org.junit.rules.TestRule;
+import org.junit.runner.Description;
+import org.junit.runners.model.Statement;
+
+public class HttpClientRule implements TestRule {
+	private CloseableHttpClient myClient;
+
+	@Override
+	public Statement apply(Statement theBase, Description theDescription) {
+		return new Statement() {
+			@Override
+			public void evaluate() throws Throwable {
+				startClient();
+				theBase.evaluate();
+				stopClient();
+			}
+		};
+	}
+
+
+	private void stopClient() throws Exception {
+		myClient.close();
+	}
+
+	private void startClient() {
+		myClient = HttpClientBuilder
+			.create()
+			.build();
+	}
+
+	public CloseableHttpClient getClient() {
+		return myClient;
+	}
+}

hapi-fhir-validation/src/test/java/ca/uhn/fhir/fhirpath/FluentPathTest.java

@@ -1,4 +1,4 @@
-package ca.uhn.fhir.fluentpath;
+package ca.uhn.fhir.fhirpath;
 
 import ca.uhn.fhir.context.FhirContext;
 import ca.uhn.fhir.util.TestUtil;
@@ -21,7 +21,7 @@ public class FluentPathTest {
 		p.addName().setFamily("N1F1").addGiven("N1G1").addGiven("N1G2");
 		p.addName().setFamily("N2F1").addGiven("N2G1").addGiven("N2G2");
 		
-		IFluentPath fp = ourCtx.newFluentPath();
+		IFhirPath fp = ourCtx.newFluentPath();
 		List<HumanName> names = fp.evaluate(p, "Patient.name", HumanName.class);
 		assertEquals(2, names.size());
 		assertEquals("N1F1", names.get(0).getFamily());
@@ -36,7 +36,7 @@ public class FluentPathTest {
 		p.addName().setFamily("N1F1").addGiven("N1G1").addGiven("N1G2");
 		p.addName().setFamily("N2F1").addGiven("N2G1").addGiven("N2G2");
 		
-		IFluentPath fp = ourCtx.newFluentPath();
+		IFhirPath fp = ourCtx.newFluentPath();
 		List<HumanName> names = fp.evaluate(p, "Patient.nameFOO", HumanName.class);
 		assertEquals(0, names.size());
 	}
@@ -47,10 +47,10 @@ public class FluentPathTest {
 		p.addName().setFamily("N1F1").addGiven("N1G1").addGiven("N1G2");
 		p.addName().setFamily("N2F1").addGiven("N2G1").addGiven("N2G2");
 		
-		IFluentPath fp = ourCtx.newFluentPath();
+		IFhirPath fp = ourCtx.newFluentPath();
 		try {
 			fp.evaluate(p, "Patient....nameFOO", HumanName.class);
-		} catch (FluentPathExecutionException e) {
+		} catch (FhirPathExecutionException e) {
 			assertThat(e.getMessage(), containsString("termination at unexpected token"));
 		}
 	}
@@ -61,10 +61,10 @@ public class FluentPathTest {
 		p.addName().setFamily("N1F1").addGiven("N1G1").addGiven("N1G2");
 		p.addName().setFamily("N2F1").addGiven("N2G1").addGiven("N2G2");
 		
-		IFluentPath fp = ourCtx.newFluentPath();
+		IFhirPath fp = ourCtx.newFluentPath();
 		try {
 			fp.evaluate(p, "Patient.name", StringType.class);
-		} catch (FluentPathExecutionException e) {
+		} catch (FhirPathExecutionException e) {
 			assertEquals("FluentPath expression \"Patient.name\" returned unexpected type HumanName - Expected org.hl7.fhir.dstu3.model.StringType", e.getMessage());
 		}
 	}

hapi-tinder-plugin/src/main/java/ca/uhn/fhir/model/dstu2/FhirDstu2.java

@@ -23,11 +23,11 @@ package ca.uhn.fhir.model.dstu2;
 import java.io.InputStream;
 import java.util.Date;
 
+import ca.uhn.fhir.fhirpath.IFhirPath;
 import org.apache.commons.lang3.StringUtils;
 import org.hl7.fhir.instance.model.api.*;
 
 import ca.uhn.fhir.context.*;
-import ca.uhn.fhir.fluentpath.IFluentPath;
 import ca.uhn.fhir.model.api.*;
 import ca.uhn.fhir.model.base.composite.*;
 import ca.uhn.fhir.model.dstu2.composite.*;
@@ -41,7 +41,7 @@ public class FhirDstu2 implements IFhirVersion {
 	private String myId;
 
 	@Override
-	public IFluentPath createFluentPathExecutor(FhirContext theFhirContext) {
+	public IFhirPath createFluentPathExecutor(FhirContext theFhirContext) {
 		throw new UnsupportedOperationException("FluentPath is not supported in DSTU2 contexts");
 	}