Allow operations to better work across multiple versions of FHIR

hapi-fhir-base/src/main/java/ca/uhn/fhir/rest/annotation/OperationParam.java

@@ -75,6 +75,14 @@ public @interface OperationParam {
 	 * </ul>
 	 */
 	Class<? extends IBase> type() default IBase.class;
+
+	/**
+	 * Optionally specifies the type of the parameter as a string, such as <code>Coding</code> or
+	 * <code>base64Binary</code>. This can be useful if you want to use a generic interface type
+	 * on the actual method,such as {@link org.hl7.fhir.instance.model.api.IPrimitiveType} or
+	 * {@link @org.hl7.fhir.instance.model.api.ICompositeType}.
+	 */
+	String typeName() default "";
 	
 	/**
 	 * The minimum number of repetitions allowed for this child (default is 0)

hapi-fhir-server/src/main/java/ca/uhn/fhir/rest/server/method/MethodUtil.java

@@ -219,7 +219,15 @@ public class MethodUtil {
 						param = new ConditionalParamBinder(theRestfulOperationTypeEnum, ((ConditionalUrlParam) nextAnnotation).supportsMultiple());
 					} else if (nextAnnotation instanceof OperationParam) {
 						Operation op = theMethod.getAnnotation(Operation.class);
-						param = new OperationParameter(theContext, op.name(), ((OperationParam) nextAnnotation));
+						OperationParam operationParam = (OperationParam) nextAnnotation;
+						param = new OperationParameter(theContext, op.name(), operationParam);
+						if (isNotBlank(operationParam.typeName())) {
+							Class<?> newParameterType = theContext.getElementDefinition(operationParam.typeName()).getImplementingClass();
+							if (!parameterType.isAssignableFrom(newParameterType)) {
+								throw new ConfigurationException("Non assignable parameter typeName=\"" + operationParam.typeName() + "\" specified on method " + theMethod);
+							}
+							parameterType = newParameterType;
+						}
 					} else if (nextAnnotation instanceof Validate.Mode) {
 						if (parameterType.equals(ValidationModeEnum.class) == false) {
 							throw new ConfigurationException(

hapi-fhir-server/src/main/java/ca/uhn/fhir/rest/server/method/OperationParameter.java

@@ -151,12 +151,10 @@ public class OperationParameter implements IParameter {
 
 		boolean typeIsConcrete = !myParameterType.isInterface() && !Modifier.isAbstract(myParameterType.getModifiers());
 
-		//@formatter:off
 		boolean isSearchParam =
 			IQueryParameterType.class.isAssignableFrom(myParameterType) ||
 				IQueryParameterOr.class.isAssignableFrom(myParameterType) ||
 				IQueryParameterAnd.class.isAssignableFrom(myParameterType);
-		//@formatter:off
 
 		/*
 		 * Note: We say here !IBase.class.isAssignableFrom because a bunch of DSTU1/2 datatypes also

hapi-fhir-structures-r4/src/test/java/ca/uhn/fhir/rest/server/OperationGenericServer2R4Test.java

@@ -0,0 +1,185 @@
+package ca.uhn.fhir.rest.server;
+
+import ca.uhn.fhir.context.ConfigurationException;
+import ca.uhn.fhir.context.FhirContext;
+import ca.uhn.fhir.rest.annotation.IdParam;
+import ca.uhn.fhir.rest.annotation.Operation;
+import ca.uhn.fhir.rest.annotation.OperationParam;
+import ca.uhn.fhir.rest.annotation.ResourceParam;
+import ca.uhn.fhir.rest.api.Constants;
+import ca.uhn.fhir.rest.api.EncodingEnum;
+import ca.uhn.fhir.test.utilities.JettyUtil;
+import ca.uhn.fhir.util.TestUtil;
+import org.apache.commons.io.IOUtils;
+import org.apache.http.client.methods.CloseableHttpResponse;
+import org.apache.http.client.methods.HttpPost;
+import org.apache.http.entity.ContentType;
+import org.apache.http.entity.StringEntity;
+import org.apache.http.impl.client.CloseableHttpClient;
+import org.apache.http.impl.client.HttpClientBuilder;
+import org.apache.http.impl.conn.PoolingHttpClientConnectionManager;
+import org.eclipse.jetty.server.Server;
+import org.eclipse.jetty.servlet.ServletHandler;
+import org.eclipse.jetty.servlet.ServletHolder;
+import org.hl7.fhir.instance.model.api.IBaseResource;
+import org.hl7.fhir.instance.model.api.ICompositeType;
+import org.hl7.fhir.instance.model.api.IPrimitiveType;
+import org.hl7.fhir.r4.model.*;
+import org.junit.*;
+
+import javax.servlet.ServletException;
+import java.nio.charset.StandardCharsets;
+import java.util.concurrent.TimeUnit;
+
+import static org.junit.Assert.assertEquals;
+import static org.junit.Assert.fail;
+
+public class OperationGenericServer2R4Test {
+	private static final org.slf4j.Logger ourLog = org.slf4j.LoggerFactory.getLogger(OperationGenericServer2R4Test.class);
+	private static CloseableHttpClient ourClient;
+	private static FhirContext ourCtx;
+	private static IdType ourLastId;
+	private static Object ourLastParam1;
+	private static Object ourLastParam2;
+	private static Parameters ourLastResourceParam;
+	private int myPort;
+	private Server myServer;
+
+	@Before
+	public void before() {
+		ourLastParam1 = null;
+		ourLastParam2 = null;
+		ourLastId = null;
+		ourLastResourceParam = null;
+	}
+
+
+	@Test
+	public void testDeclarativeTypedParameters() throws Exception {
+
+		@SuppressWarnings("unused")
+		class PatientProvider implements IResourceProvider {
+
+			@Override
+			public Class<Patient> getResourceType() {
+				return Patient.class;
+			}
+
+			@Operation(name = "$OP_INSTANCE")
+			public Parameters opInstance(
+				@ResourceParam() IBaseResource theResourceParam,
+				@IdParam IdType theId,
+				@OperationParam(name = "PARAM1", typeName = "code") IPrimitiveType<String> theParam1,
+				@OperationParam(name = "PARAM2", typeName = "Coding") ICompositeType theParam2
+			) {
+
+				ourLastId = theId;
+				ourLastParam1 = theParam1;
+				ourLastParam2 = theParam2;
+				ourLastResourceParam = (Parameters) theResourceParam;
+
+				Parameters retVal = new Parameters();
+				retVal.addParameter().setName("RET1").setValue(new StringType("RETVAL1"));
+				return retVal;
+			}
+
+		}
+
+		PatientProvider provider = new PatientProvider();
+		startServer(provider);
+
+		Parameters p = new Parameters();
+		p.addParameter().setName("PARAM1").setValue(new CodeType("PARAM1val"));
+		p.addParameter().setName("PARAM2").setValue(new Coding("sys", "val", "dis"));
+		String inParamsStr = ourCtx.newXmlParser().encodeResourceToString(p);
+
+		HttpPost httpPost = new HttpPost("http://localhost:" + myPort + "/Patient/123/$OP_INSTANCE");
+		httpPost.setEntity(new StringEntity(inParamsStr, ContentType.create(Constants.CT_FHIR_XML, "UTF-8")));
+		try (CloseableHttpResponse status = ourClient.execute(httpPost)) {
+			assertEquals(200, status.getStatusLine().getStatusCode());
+			String response = IOUtils.toString(status.getEntity().getContent(), StandardCharsets.UTF_8);
+			ourLog.info(response);
+			status.getEntity().getContent().close();
+
+			CodeType param1 = (CodeType) ourLastParam1;
+			assertEquals("PARAM1val", param1.getValue());
+
+			Coding param2 = (Coding) ourLastParam2;
+			assertEquals("sys", param2.getSystem());
+			assertEquals("val", param2.getCode());
+			assertEquals("dis", param2.getDisplay());
+		}
+
+	}
+
+	@Test
+	public void testDeclarativeTypedParametersInvalid() throws Exception {
+
+		@SuppressWarnings("unused")
+		class PatientProvider implements IResourceProvider {
+
+			@Override
+			public Class<Patient> getResourceType() {
+				return Patient.class;
+			}
+
+			@Operation(name = "$OP_INSTANCE")
+			public Parameters opInstance(
+				@OperationParam(name = "PARAM2", typeName = "code") ICompositeType theParam2
+			) {
+				return new Parameters();
+			}
+
+		}
+
+		try {
+			PatientProvider provider = new PatientProvider();
+			startServer(provider);
+			fail();
+		} catch (ServletException e) {
+			ConfigurationException ce = (ConfigurationException) e.getCause();
+			assertEquals("Failure scanning class PatientProvider: Non assignable parameter typeName=\"code\" specified on method public org.hl7.fhir.r4.model.Parameters ca.uhn.fhir.rest.server.OperationGenericServer2R4Test$2PatientProvider.opInstance(org.hl7.fhir.instance.model.api.ICompositeType)", ce.getMessage());
+		}
+	}
+
+	private void startServer(Object theProvider) throws Exception {
+		myServer = new Server(0);
+
+		ServletHandler proxyHandler = new ServletHandler();
+		RestfulServer servlet = new RestfulServer(ourCtx);
+		servlet.setDefaultResponseEncoding(EncodingEnum.XML);
+
+		servlet.setPagingProvider(new FifoMemoryPagingProvider(10).setDefaultPageSize(2));
+
+		servlet.setFhirContext(ourCtx);
+		servlet.registerProvider(theProvider);
+		ServletHolder servletHolder = new ServletHolder(servlet);
+		proxyHandler.addServletWithMapping(servletHolder, "/*");
+		myServer.setHandler(proxyHandler);
+		JettyUtil.startServer(myServer);
+		myPort = JettyUtil.getPortForStartedServer(myServer);
+	}
+
+
+	@After
+	public void after() throws Exception {
+		JettyUtil.closeServer(myServer);
+	}
+
+	@AfterClass
+	public static void afterClassClearContext() {
+		TestUtil.clearAllStaticFieldsForUnitTest();
+	}
+
+	@BeforeClass
+	public static void beforeClass() {
+		ourCtx = FhirContext.forR4();
+
+		PoolingHttpClientConnectionManager connectionManager = new PoolingHttpClientConnectionManager(5000, TimeUnit.MILLISECONDS);
+		HttpClientBuilder builder = HttpClientBuilder.create();
+		builder.setConnectionManager(connectionManager);
+		ourClient = builder.build();
+
+	}
+
+}

src/changes/changes.xml

@@ -310,6 +310,11 @@
 				apply to all resource types (or instances of all resource types) if they
 				are found on a plain provider.
 			</action>
+			<action type="add">
+				@Operation method parameters may now declare their type via a String name such as
+				"code" or "Coding" in an attribute in @OperationParam. This is useful if you want
+				to make operation methods that can operate across different versions of FHIR.
+			</action>
 			<action type="add">
 				A new resource provider for JPA servers called
 				<![CDATA[<code>BinaryAccessProvider</code>]]>
@@ -335,7 +340,6 @@
 				a narrative on an untitled DiagnosticReport were fixed. Thanks to GitHub
 				user @navyflower for reporting!
 			</action>
-
 		</release>
 		<release version="3.8.0" date="2019-05-30" description="Hippo">
 			<action type="fix">