Merge pull request #2850 from hapifhir/2849_add_new_mdm_param

Added new parameter to MDM processing

hapi-fhir-base/src/main/java/ca/uhn/fhir/interceptor/api/Pointcut.java

@@ -1986,13 +1986,17 @@ public enum Pointcut implements IPointcut {
 	 * <ul>
 	 * <li>ca.uhn.fhir.rest.server.messaging.ResourceOperationMessage - This parameter should not be modified as processing is complete when this hook is invoked.</li>
 	 * <li>ca.uhn.fhir.rest.server.TransactionLogMessages - This parameter is for informational messages provided by the MDM module during MDM processing.</li>
+	 * <li>ca.uhn.fhir.mdm.api.MdmLinkChangeEvent - Contains information about the change event, including target and golden resource IDs and the operation type.</li>
 	 * </ul>
 	 * </p>
 	 * <p>
 	 * Hooks should return <code>void</code>.
 	 * </p>
 	 */
-	MDM_AFTER_PERSISTED_RESOURCE_CHECKED(void.class, "ca.uhn.fhir.rest.server.messaging.ResourceOperationMessage", "ca.uhn.fhir.rest.server.TransactionLogMessages"),
+	MDM_AFTER_PERSISTED_RESOURCE_CHECKED(void.class,
+		"ca.uhn.fhir.rest.server.messaging.ResourceOperationMessage",
+		"ca.uhn.fhir.rest.server.TransactionLogMessages",
+		"ca.uhn.fhir.mdm.api.MdmLinkEvent"),
 
 	/**
 	 * <b>Performance Tracing Hook:</b>

hapi-fhir-docs/src/main/resources/ca/uhn/hapi/fhir/changelog/5_6_0/2850-updated-mdm-pointcut.yaml

@@ -0,0 +1,4 @@
+---
+type: add
+issue: 2850
+title: "Updated handling of MDM_AFTER_PERSISTED_RESOURCE_CHECKED pointcut to include additional MDM related info."

hapi-fhir-jpaserver-base/src/main/java/ca/uhn/fhir/jpa/entity/MdmLink.java

@@ -20,6 +20,7 @@ package ca.uhn.fhir.jpa.entity;
  * #L%
  */
 
+import ca.uhn.fhir.mdm.api.IMdmLink;
 import ca.uhn.fhir.mdm.api.MdmLinkSourceEnum;
 import ca.uhn.fhir.mdm.api.MdmMatchResultEnum;
 import ca.uhn.fhir.jpa.model.entity.ResourceTable;
@@ -47,7 +48,7 @@ import java.util.Date;
 @Table(name = "MPI_LINK", uniqueConstraints = {
 	@UniqueConstraint(name = "IDX_EMPI_PERSON_TGT", columnNames = {"PERSON_PID", "TARGET_PID"}),
 })
-public class MdmLink {
+public class MdmLink implements IMdmLink {
 	public static final int VERSION_LENGTH = 16;
 	private static final int MATCH_RESULT_LENGTH = 16;
 	private static final int LINK_SOURCE_LENGTH = 16;

hapi-fhir-jpaserver-mdm/src/main/java/ca/uhn/fhir/jpa/mdm/broker/MdmMessageHandler.java

@@ -24,18 +24,23 @@ import ca.uhn.fhir.context.FhirContext;
 import ca.uhn.fhir.interceptor.api.HookParams;
 import ca.uhn.fhir.interceptor.api.IInterceptorBroadcaster;
 import ca.uhn.fhir.interceptor.api.Pointcut;
+import ca.uhn.fhir.jpa.entity.MdmLink;
+import ca.uhn.fhir.jpa.mdm.dao.MdmLinkDaoSvc;
+import ca.uhn.fhir.jpa.mdm.svc.IMdmModelConverterSvc;
 import ca.uhn.fhir.jpa.mdm.svc.MdmMatchLinkSvc;
 import ca.uhn.fhir.jpa.mdm.svc.MdmResourceFilteringSvc;
 import ca.uhn.fhir.jpa.mdm.svc.candidate.TooManyCandidatesException;
 import ca.uhn.fhir.jpa.subscription.model.ResourceModifiedJsonMessage;
 import ca.uhn.fhir.jpa.subscription.model.ResourceModifiedMessage;
 import ca.uhn.fhir.mdm.api.IMdmSettings;
+import ca.uhn.fhir.mdm.api.MdmLinkEvent;
 import ca.uhn.fhir.mdm.log.Logs;
 import ca.uhn.fhir.mdm.model.MdmTransactionContext;
 import ca.uhn.fhir.rest.server.TransactionLogMessages;
 import ca.uhn.fhir.rest.server.exceptions.InvalidRequestException;
 import ca.uhn.fhir.rest.server.messaging.ResourceOperationMessage;
 import org.hl7.fhir.instance.model.api.IAnyResource;
+import org.hl7.fhir.instance.model.api.IBaseResource;
 import org.slf4j.Logger;
 import org.springframework.beans.factory.annotation.Autowired;
 import org.springframework.messaging.Message;
@@ -43,11 +48,15 @@ import org.springframework.messaging.MessageHandler;
 import org.springframework.messaging.MessagingException;
 import org.springframework.stereotype.Service;
 
+import java.util.Optional;
+
 @Service
 public class MdmMessageHandler implements MessageHandler {
 
 	private static final Logger ourLog = Logs.getMdmTroubleshootingLog();
 
+	@Autowired
+	private MdmLinkDaoSvc myMdmLinkDaoSvc;
 	@Autowired
 	private MdmMatchLinkSvc myMdmMatchLinkSvc;
 	@Autowired
@@ -58,6 +67,8 @@ public class MdmMessageHandler implements MessageHandler {
 	private MdmResourceFilteringSvc myMdmResourceFilteringSvc;
 	@Autowired
 	private IMdmSettings myMdmSettings;
+	@Autowired
+	private IMdmModelConverterSvc myModelConverter;
 
 	@Override
 	public void handleMessage(Message<?> theMessage) throws MessagingException {
@@ -89,11 +100,11 @@ public class MdmMessageHandler implements MessageHandler {
 		try {
 			switch (theMsg.getOperationType()) {
 				case CREATE:
-					handleCreatePatientOrPractitioner(theMsg, mdmContext);
+					handleCreateResource(theMsg, mdmContext);
 					break;
 				case UPDATE:
 				case MANUALLY_TRIGGERED:
-					handleUpdatePatientOrPractitioner(theMsg, mdmContext);
+					handleUpdateResource(theMsg, mdmContext);
 					break;
 				case DELETE:
 				default:
@@ -103,14 +114,23 @@ public class MdmMessageHandler implements MessageHandler {
 			log(mdmContext, "Failure during MDM processing: " + e.getMessage(), e);
 			mdmContext.addTransactionLogMessage(e.getMessage());
 		} finally {
-
 			// Interceptor call: MDM_AFTER_PERSISTED_RESOURCE_CHECKED
-			ResourceOperationMessage outgoingMsg = new ResourceOperationMessage(myFhirContext, theMsg.getPayload(myFhirContext), theMsg.getOperationType());
+			IBaseResource targetResource = theMsg.getPayload(myFhirContext);
+			ResourceOperationMessage outgoingMsg = new ResourceOperationMessage(myFhirContext, targetResource, theMsg.getOperationType());
 			outgoingMsg.setTransactionId(theMsg.getTransactionId());
 
+			MdmLinkEvent linkChangeEvent = new MdmLinkEvent();
+			mdmContext.getMdmLinks()
+				.stream()
+				.forEach(l -> {
+					linkChangeEvent.addMdmLink(myModelConverter.toJson((MdmLink) l));
+				});
+
 			HookParams params = new HookParams()
 				.add(ResourceOperationMessage.class, outgoingMsg)
-				.add(TransactionLogMessages.class, mdmContext.getTransactionLogMessages());
+				.add(TransactionLogMessages.class, mdmContext.getTransactionLogMessages())
+				.add(MdmLinkEvent.class, linkChangeEvent);
+
 			myInterceptorBroadcaster.callHooks(Pointcut.MDM_AFTER_PERSISTED_RESOURCE_CHECKED, params);
 		}
 	}
@@ -142,7 +162,7 @@ public class MdmMessageHandler implements MessageHandler {
 		}
 	}
 
-	private void handleCreatePatientOrPractitioner(ResourceModifiedMessage theMsg, MdmTransactionContext theMdmTransactionContext) {
+	private void handleCreateResource(ResourceModifiedMessage theMsg, MdmTransactionContext theMdmTransactionContext) {
 		myMdmMatchLinkSvc.updateMdmLinksForMdmSource(getResourceFromPayload(theMsg), theMdmTransactionContext);
 	}
 
@@ -150,7 +170,7 @@ public class MdmMessageHandler implements MessageHandler {
 		return (IAnyResource) theMsg.getNewPayload(myFhirContext);
 	}
 
-	private void handleUpdatePatientOrPractitioner(ResourceModifiedMessage theMsg, MdmTransactionContext theMdmTransactionContext) {
+	private void handleUpdateResource(ResourceModifiedMessage theMsg, MdmTransactionContext theMdmTransactionContext) {
 		myMdmMatchLinkSvc.updateMdmLinksForMdmSource(getResourceFromPayload(theMsg), theMdmTransactionContext);
 	}
 

hapi-fhir-jpaserver-mdm/src/main/java/ca/uhn/fhir/jpa/mdm/config/MdmConsumerConfig.java

@@ -32,13 +32,15 @@ import ca.uhn.fhir.jpa.mdm.dao.MdmLinkFactory;
 import ca.uhn.fhir.jpa.mdm.interceptor.IMdmStorageInterceptor;
 import ca.uhn.fhir.jpa.mdm.interceptor.MdmStorageInterceptor;
 import ca.uhn.fhir.jpa.mdm.svc.GoldenResourceMergerSvcImpl;
+import ca.uhn.fhir.jpa.mdm.svc.IMdmModelConverterSvc;
 import ca.uhn.fhir.jpa.mdm.svc.MdmControllerSvcImpl;
 import ca.uhn.fhir.jpa.mdm.svc.MdmEidUpdateService;
-import ca.uhn.fhir.jpa.mdm.svc.MdmLinkQuerySvcImpl;
+import ca.uhn.fhir.jpa.mdm.svc.MdmLinkQuerySvcImplSvc;
 import ca.uhn.fhir.jpa.mdm.svc.MdmLinkSvcImpl;
 import ca.uhn.fhir.jpa.mdm.svc.MdmLinkUpdaterSvcImpl;
 import ca.uhn.fhir.jpa.mdm.svc.MdmMatchFinderSvcImpl;
 import ca.uhn.fhir.jpa.mdm.svc.MdmMatchLinkSvc;
+import ca.uhn.fhir.jpa.mdm.svc.MdmModelConverterSvcImpl;
 import ca.uhn.fhir.jpa.mdm.svc.MdmResourceDaoSvc;
 import ca.uhn.fhir.jpa.mdm.svc.MdmResourceFilteringSvc;
 import ca.uhn.fhir.jpa.mdm.svc.MdmSearchParamSvc;
@@ -178,7 +180,12 @@ public class MdmConsumerConfig {
 
 	@Bean
 	IMdmLinkQuerySvc mdmLinkQuerySvc() {
-		return new MdmLinkQuerySvcImpl();
+		return new MdmLinkQuerySvcImplSvc();
+	}
+
+	@Bean
+	IMdmModelConverterSvc mdmModelConverterSvc() {
+		return new MdmModelConverterSvcImpl();
 	}
 
 	@Bean

hapi-fhir-jpaserver-mdm/src/main/java/ca/uhn/fhir/jpa/mdm/svc/IMdmModelConverterSvc.java

@@ -0,0 +1,39 @@
+package ca.uhn.fhir.jpa.mdm.svc;
+
+/*-
+ * #%L
+ * HAPI FHIR JPA Server - Master Data Management
+ * %%
+ * Copyright (C) 2014 - 2021 Smile CDR, Inc.
+ * %%
+ * 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 ca.uhn.fhir.jpa.entity.MdmLink;
+import ca.uhn.fhir.mdm.api.MdmLinkJson;
+
+/**
+ * Contract for decoupling API dependency from the base / JPA modules.
+ */
+public interface IMdmModelConverterSvc {
+
+	/**
+	 * Creates JSON representation of the provided MDM link
+	 *
+	 * @param theLink Link to convert
+	 * @return Returns the converted link
+	 */
+	public MdmLinkJson toJson(MdmLink theLink);
+
+}

hapi-fhir-jpaserver-mdm/src/main/java/ca/uhn/fhir/jpa/mdm/svc/MdmLinkQuerySvcImplSvc.java

@@ -36,20 +36,24 @@ import org.springframework.beans.factory.annotation.Autowired;
 import org.springframework.data.domain.Example;
 import org.springframework.data.domain.Page;
 
-public class MdmLinkQuerySvcImpl implements IMdmLinkQuerySvc {
+public class MdmLinkQuerySvcImplSvc implements IMdmLinkQuerySvc {
 
-	private static final Logger ourLog = LoggerFactory.getLogger(MdmLinkQuerySvcImpl.class);
+	private static final Logger ourLog = LoggerFactory.getLogger(MdmLinkQuerySvcImplSvc.class);
+
+	@Autowired
+	MdmLinkDaoSvc myMdmLinkDaoSvc;
 
 	@Autowired
 	IdHelperService myIdHelperService;
+
 	@Autowired
-	MdmLinkDaoSvc myMdmLinkDaoSvc;
+	IMdmModelConverterSvc myMdmModelConverterSvc;
 
 	@Override
 	public Page<MdmLinkJson> queryLinks(IIdType theGoldenResourceId, IIdType theSourceResourceId, MdmMatchResultEnum theMatchResult, MdmLinkSourceEnum theLinkSource, MdmTransactionContext theMdmContext, MdmPageRequest thePageRequest) {
 		Example<MdmLink> exampleLink = exampleLinkFromParameters(theGoldenResourceId, theSourceResourceId, theMatchResult, theLinkSource);
 		Page<MdmLink> mdmLinkByExample = myMdmLinkDaoSvc.findMdmLinkByExample(exampleLink, thePageRequest);
-		Page<MdmLinkJson> map = mdmLinkByExample.map(this::toJson);
+		Page<MdmLinkJson> map = mdmLinkByExample.map(myMdmModelConverterSvc::toJson);
 		return map;
 	}
 
@@ -57,28 +61,10 @@ public class MdmLinkQuerySvcImpl implements IMdmLinkQuerySvc {
 	public Page<MdmLinkJson> getDuplicateGoldenResources(MdmTransactionContext theMdmContext, MdmPageRequest thePageRequest) {
 		Example<MdmLink> exampleLink = exampleLinkFromParameters(null, null, MdmMatchResultEnum.POSSIBLE_DUPLICATE, null);
 		Page<MdmLink> mdmLinkPage = myMdmLinkDaoSvc.findMdmLinkByExample(exampleLink, thePageRequest);
-		Page<MdmLinkJson> map = mdmLinkPage.map(this::toJson);
+		Page<MdmLinkJson> map = mdmLinkPage.map(myMdmModelConverterSvc::toJson);
 		return map;
 	}
 
-	private MdmLinkJson toJson(MdmLink theLink) {
-		MdmLinkJson retval = new MdmLinkJson();
-		String sourceId = myIdHelperService.resourceIdFromPidOrThrowException(theLink.getSourcePid()).toVersionless().getValue();
-		retval.setSourceId(sourceId);
-		String goldenResourceId = myIdHelperService.resourceIdFromPidOrThrowException(theLink.getGoldenResourcePid()).toVersionless().getValue();
-		retval.setGoldenResourceId(goldenResourceId);
-		retval.setCreated(theLink.getCreated());
-		retval.setEidMatch(theLink.getEidMatch());
-		retval.setLinkSource(theLink.getLinkSource());
-		retval.setMatchResult(theLink.getMatchResult());
-		retval.setLinkCreatedNewResource(theLink.getHadToCreateNewGoldenResource());
-		retval.setScore(theLink.getScore());
-		retval.setUpdated(theLink.getUpdated());
-		retval.setVector(theLink.getVector());
-		retval.setVersion(theLink.getVersion());
-		return retval;
-	}
-
 	private Example<MdmLink> exampleLinkFromParameters(IIdType theGoldenResourceId, IIdType theSourceId, MdmMatchResultEnum theMatchResult, MdmLinkSourceEnum theLinkSource) {
 		MdmLink mdmLink = myMdmLinkDaoSvc.newMdmLink();
 		if (theGoldenResourceId != null) {

hapi-fhir-jpaserver-mdm/src/main/java/ca/uhn/fhir/jpa/mdm/svc/MdmLinkSvcImpl.java

@@ -53,6 +53,8 @@ public class MdmLinkSvcImpl implements IMdmLinkSvc {
 	private MdmLinkDaoSvc myMdmLinkDaoSvc;
 	@Autowired
 	private IdHelperService myIdHelperService;
+	@Autowired
+	private IMdmModelConverterSvc myMdmModelConverterSvc;
 
 	@Override
 	@Transactional
@@ -69,7 +71,8 @@ public class MdmLinkSvcImpl implements IMdmLinkSvc {
 		validateRequestIsLegal(theGoldenResource, theSourceResource, matchResultEnum, theLinkSource);
 
 		myMdmResourceDaoSvc.upsertGoldenResource(theGoldenResource, theMdmTransactionContext.getResourceType());
-		createOrUpdateLinkEntity(theGoldenResource, theSourceResource, theMatchOutcome, theLinkSource, theMdmTransactionContext);
+		MdmLink link = createOrUpdateLinkEntity(theGoldenResource, theSourceResource, theMatchOutcome, theLinkSource, theMdmTransactionContext);
+		theMdmTransactionContext.addMdmLink(link);
 	}
 
 	private boolean goldenResourceLinkedAsNoMatch(IAnyResource theGoldenResource, IAnyResource theSourceResource) {
@@ -87,6 +90,7 @@ public class MdmLinkSvcImpl implements IMdmLinkSvc {
 			MdmLink mdmLink = optionalMdmLink.get();
 			log(theMdmTransactionContext, "Deleting MdmLink [" + theGoldenResource.getIdElement().toVersionless() + " -> " + theSourceResource.getIdElement().toVersionless() + "] with result: " + mdmLink.getMatchResult());
 			myMdmLinkDaoSvc.deleteLink(mdmLink);
+			theMdmTransactionContext.addMdmLink(mdmLink);
 		}
 	}
 
@@ -129,8 +133,8 @@ public class MdmLinkSvcImpl implements IMdmLinkSvc {
 		}
 	}
 
-	private void createOrUpdateLinkEntity(IBaseResource theGoldenResource, IBaseResource theSourceResource, MdmMatchOutcome theMatchOutcome, MdmLinkSourceEnum theLinkSource, MdmTransactionContext theMdmTransactionContext) {
+	private MdmLink createOrUpdateLinkEntity(IBaseResource theGoldenResource, IBaseResource theSourceResource, MdmMatchOutcome theMatchOutcome, MdmLinkSourceEnum theLinkSource, MdmTransactionContext theMdmTransactionContext) {
-		myMdmLinkDaoSvc.createOrUpdateLinkEntity(theGoldenResource, theSourceResource, theMatchOutcome, theLinkSource, theMdmTransactionContext);
+		return myMdmLinkDaoSvc.createOrUpdateLinkEntity(theGoldenResource, theSourceResource, theMatchOutcome, theLinkSource, theMdmTransactionContext);
 	}
 
 	private void log(MdmTransactionContext theMdmTransactionContext, String theMessage) {

hapi-fhir-jpaserver-mdm/src/main/java/ca/uhn/fhir/jpa/mdm/svc/MdmMatchLinkSvc.java

@@ -99,6 +99,7 @@ public class MdmMatchLinkSvc {
 			handleMdmWithSingleCandidate(theResource, firstMatch, theMdmTransactionContext);
 		} else {
 			log(theMdmTransactionContext, "MDM received multiple match candidates, that were linked to different Golden Resources. Setting POSSIBLE_DUPLICATES and POSSIBLE_MATCHES.");
+
 			//Set them all as POSSIBLE_MATCH
 			List<IAnyResource> goldenResources = new ArrayList<>();
 			for (MatchedGoldenResourceCandidate matchedGoldenResourceCandidate : theCandidateList.getCandidates()) {
@@ -112,6 +113,7 @@ public class MdmMatchLinkSvc {
 
 			//Set all GoldenResources as POSSIBLE_DUPLICATE of the last GoldenResource.
 			IAnyResource firstGoldenResource = goldenResources.get(0);
+
 			goldenResources.subList(1, goldenResources.size())
 				.forEach(possibleDuplicateGoldenResource -> {
 					MdmMatchOutcome outcome = MdmMatchOutcome.POSSIBLE_DUPLICATE;
@@ -138,6 +140,7 @@ public class MdmMatchLinkSvc {
 		if (myGoldenResourceHelper.isPotentialDuplicate(goldenResource, theTargetResource)) {
 			log(theMdmTransactionContext, "Duplicate detected based on the fact that both resources have different external EIDs.");
 			IAnyResource newGoldenResource = myGoldenResourceHelper.createGoldenResourceFromMdmSourceResource(theTargetResource, theMdmTransactionContext);
+
 			myMdmLinkSvc.updateLink(newGoldenResource, theTargetResource, MdmMatchOutcome.NEW_GOLDEN_RESOURCE_MATCH, MdmLinkSourceEnum.AUTO, theMdmTransactionContext);
 			myMdmLinkSvc.updateLink(newGoldenResource, goldenResource, MdmMatchOutcome.POSSIBLE_DUPLICATE, MdmLinkSourceEnum.AUTO, theMdmTransactionContext);
 		} else {
@@ -145,6 +148,7 @@ public class MdmMatchLinkSvc {
 				myGoldenResourceHelper.handleExternalEidAddition(goldenResource, theTargetResource, theMdmTransactionContext);
 				myEidUpdateService.applySurvivorshipRulesAndSaveGoldenResource(theTargetResource, goldenResource, theMdmTransactionContext);
 			}
+
 			myMdmLinkSvc.updateLink(goldenResource, theTargetResource, theGoldenResourceCandidate.getMatchResult(), MdmLinkSourceEnum.AUTO, theMdmTransactionContext);
 		}
 	}

hapi-fhir-jpaserver-mdm/src/main/java/ca/uhn/fhir/jpa/mdm/svc/MdmModelConverterSvcImpl.java

@@ -0,0 +1,52 @@
+package ca.uhn.fhir.jpa.mdm.svc;
+
+/*-
+ * #%L
+ * HAPI FHIR JPA Server - Master Data Management
+ * %%
+ * Copyright (C) 2014 - 2021 Smile CDR, Inc.
+ * %%
+ * 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 ca.uhn.fhir.jpa.dao.index.IdHelperService;
+import ca.uhn.fhir.jpa.entity.MdmLink;
+import ca.uhn.fhir.mdm.api.MdmLinkJson;
+import org.springframework.beans.factory.annotation.Autowired;
+
+public class MdmModelConverterSvcImpl implements IMdmModelConverterSvc {
+
+	@Autowired
+	IdHelperService myIdHelperService;
+
+	public MdmLinkJson toJson(MdmLink theLink) {
+		MdmLinkJson retVal = new MdmLinkJson();
+		String sourceId = myIdHelperService.resourceIdFromPidOrThrowException(theLink.getSourcePid()).toVersionless().getValue();
+		retVal.setSourceId(sourceId);
+		String goldenResourceId = myIdHelperService.resourceIdFromPidOrThrowException(theLink.getGoldenResourcePid()).toVersionless().getValue();
+		retVal.setGoldenResourceId(goldenResourceId);
+		retVal.setCreated(theLink.getCreated());
+		retVal.setEidMatch(theLink.getEidMatch());
+		retVal.setLinkSource(theLink.getLinkSource());
+		retVal.setMatchResult(theLink.getMatchResult());
+		retVal.setLinkCreatedNewResource(theLink.getHadToCreateNewGoldenResource());
+		retVal.setScore(theLink.getScore());
+		retVal.setUpdated(theLink.getUpdated());
+		retVal.setVector(theLink.getVector());
+		retVal.setVersion(theLink.getVersion());
+		retVal.setRuleCount(theLink.getRuleCount());
+		return retVal;
+	}
+
+}

hapi-fhir-jpaserver-mdm/src/main/java/ca/uhn/fhir/jpa/mdm/svc/candidate/FindCandidateByExampleSvc.java

@@ -54,9 +54,9 @@ public class FindCandidateByExampleSvc extends BaseCandidateFinder {
 	private IMdmMatchFinderSvc myMdmMatchFinderSvc;
 
 	/**
-	 * Attempt to find matching Golden Resources by resolving them from similar Matching target resources, where target resource
+	 * Attempt to find matching Golden Resources by resolving them from similar Matching target resources. Runs MDM logic
-	 * can be either Patient or Practitioner. Runs MDM logic over the existing target resources, then finds their
+	 * over the existing target resources, then finds their entries in the MdmLink table, and returns all the matches
-	 * entries in the MdmLink table, and returns all the matches found therein.
+	 * found therein.
 	 *
 	 * @param theTarget the {@link IBaseResource} which we want to find candidate Golden Resources for.
 	 * @return an Optional list of {@link MatchedGoldenResourceCandidate} indicating matches.

hapi-fhir-jpaserver-mdm/src/test/java/ca/uhn/fhir/jpa/mdm/BaseMdmR4Test.java

@@ -325,14 +325,14 @@ abstract public class BaseMdmR4Test extends BaseJpaR4Test {
 		assertEquals(theExpectedCount, myMdmLinkDao.count());
 	}
 
-	protected IAnyResource getGoldenResourceFromTargetResource(IAnyResource theBaseResource) {
+	protected <T extends IAnyResource> T getGoldenResourceFromTargetResource(T theBaseResource) {
 		String resourceType = theBaseResource.getIdElement().getResourceType();
 		IFhirResourceDao relevantDao = myDaoRegistry.getResourceDao(resourceType);
 
 		Optional<MdmLink> matchedLinkForTargetPid = myMdmLinkDaoSvc.getMatchedLinkForSourcePid(myIdHelperService.getPidOrNull(theBaseResource));
 		if (matchedLinkForTargetPid.isPresent()) {
 			Long goldenResourcePid = matchedLinkForTargetPid.get().getGoldenResourcePid();
-			return (IAnyResource) relevantDao.readByPid(new ResourcePersistentId(goldenResourcePid));
+			return (T) relevantDao.readByPid(new ResourcePersistentId(goldenResourcePid));
 		} else {
 			return null;
 		}

hapi-fhir-jpaserver-mdm/src/test/java/ca/uhn/fhir/jpa/mdm/helper/BaseMdmHelper.java

@@ -106,5 +106,8 @@ public abstract class BaseMdmHelper implements BeforeEachCallback, AfterEachCall
 		return channel.getQueueSizeForUnitTest();
 	}
 
+	public PointcutLatch getAfterMdmLatch() {
+		return myAfterMdmLatch;
+	}
 
 }

hapi-fhir-jpaserver-mdm/src/test/java/ca/uhn/fhir/jpa/mdm/interceptor/MdmEventIT.java

@@ -0,0 +1,142 @@
+package ca.uhn.fhir.jpa.mdm.interceptor;
+
+import ca.uhn.fhir.jpa.dao.index.IdHelperService;
+import ca.uhn.fhir.jpa.entity.MdmLink;
+import ca.uhn.fhir.jpa.mdm.BaseMdmR4Test;
+import ca.uhn.fhir.jpa.mdm.helper.MdmHelperConfig;
+import ca.uhn.fhir.jpa.mdm.helper.MdmHelperR4;
+import ca.uhn.fhir.jpa.search.HapiLuceneAnalysisConfigurer;
+import ca.uhn.fhir.mdm.api.IMdmLink;
+import ca.uhn.fhir.mdm.api.MdmLinkEvent;
+import ca.uhn.fhir.mdm.api.MdmLinkJson;
+import ca.uhn.fhir.mdm.api.MdmMatchResultEnum;
+import ca.uhn.fhir.mdm.model.MdmTransactionContext;
+import ca.uhn.fhir.model.primitive.IdDt;
+import ca.uhn.fhir.rest.server.messaging.ResourceOperationMessage;
+import org.hibernate.dialect.H2Dialect;
+import org.hibernate.search.backend.lucene.cfg.LuceneBackendSettings;
+import org.hibernate.search.backend.lucene.cfg.LuceneIndexSettings;
+import org.hibernate.search.engine.cfg.BackendSettings;
+import org.hibernate.search.mapper.orm.cfg.HibernateOrmMapperSettings;
+import org.hl7.fhir.instance.model.api.IBaseResource;
+import org.hl7.fhir.r4.model.Patient;
+import org.hl7.fhir.r4.model.Practitioner;
+import org.junit.jupiter.api.Test;
+import org.junit.jupiter.api.extension.RegisterExtension;
+import org.slf4j.Logger;
+import org.springframework.beans.factory.annotation.Autowired;
+import org.springframework.context.annotation.Bean;
+import org.springframework.context.annotation.Primary;
+import org.springframework.data.domain.Example;
+import org.springframework.test.annotation.DirtiesContext;
+import org.springframework.test.context.ContextConfiguration;
+import org.springframework.test.context.TestPropertySource;
+
+import java.util.List;
+import java.util.Properties;
+
+import static org.junit.jupiter.api.Assertions.assertEquals;
+import static org.junit.jupiter.api.Assertions.assertFalse;
+import static org.junit.jupiter.api.Assertions.assertNotNull;
+import static org.slf4j.LoggerFactory.getLogger;
+
+@TestPropertySource(properties = {
+	"mdm.prevent_multiple_eids=false"
+})
+@DirtiesContext(classMode = DirtiesContext.ClassMode.AFTER_CLASS)
+@ContextConfiguration(classes = {MdmHelperConfig.class})
+public class MdmEventIT extends BaseMdmR4Test {
+
+	private static final Logger ourLog = getLogger(MdmEventIT.class);
+
+	@RegisterExtension
+	@Autowired
+	public MdmHelperR4 myMdmHelper;
+	@Autowired
+	private IdHelperService myIdHelperService;
+
+	@Test
+	public void testDuplicateLinkChangeEvent() throws InterruptedException {
+		Patient patient1 = buildJanePatient();
+		addExternalEID(patient1, "eid-1");
+		addExternalEID(patient1, "eid-11");
+		myMdmHelper.createWithLatch(patient1);
+
+		Patient patient2 = buildPaulPatient();
+		addExternalEID(patient2, "eid-2");
+		addExternalEID(patient2, "eid-22");
+		myMdmHelper.createWithLatch(patient2);
+
+		Patient patient3 = buildPaulPatient();
+		addExternalEID(patient3, "eid-22");
+		myMdmHelper.createWithLatch(patient3);
+
+		patient2.getIdentifier().clear();
+		addExternalEID(patient2, "eid-11");
+		addExternalEID(patient2, "eid-22");
+
+		myMdmHelper.updateWithLatch(patient2);
+
+		MdmLinkEvent linkChangeEvent = myMdmHelper.getAfterMdmLatch().getLatchInvocationParameterOfType(MdmLinkEvent.class);
+		assertNotNull(linkChangeEvent);
+
+		ourLog.info("Got event: {}", linkChangeEvent);
+
+		long expectTwoPossibleMatchesForPatientTwo = linkChangeEvent.getMdmLinks()
+			.stream()
+			.filter(l -> l.getSourceId().equals(patient2.getIdElement().toVersionless().getValueAsString()) && l.getMatchResult() == MdmMatchResultEnum.POSSIBLE_MATCH)
+			.count();
+		assertEquals(2, expectTwoPossibleMatchesForPatientTwo);
+
+		long expectOnePossibleDuplicate = linkChangeEvent.getMdmLinks()
+			.stream()
+			.filter(l -> l.getMatchResult() == MdmMatchResultEnum.POSSIBLE_DUPLICATE)
+			.count();
+		assertEquals(1, expectOnePossibleDuplicate);
+
+		List<MdmLinkJson> mdmLinkEvent = linkChangeEvent.getMdmLinks();
+		assertEquals(3, mdmLinkEvent.size());
+	}
+
+	@Test
+	public void testCreateLinkChangeEvent() throws InterruptedException {
+		Practitioner pr = buildPractitionerWithNameAndId("Young", "AC-DC");
+		myMdmHelper.createWithLatch(pr);
+
+		ResourceOperationMessage resourceOperationMessage = myMdmHelper.getAfterMdmLatch().getLatchInvocationParameterOfType(ResourceOperationMessage.class);
+		assertNotNull(resourceOperationMessage);
+		assertEquals(pr.getId(), resourceOperationMessage.getId());
+
+		MdmLink link = getLinkByTargetId(pr);
+
+		MdmLinkEvent linkChangeEvent = myMdmHelper.getAfterMdmLatch().getLatchInvocationParameterOfType(MdmLinkEvent.class);
+		assertNotNull(linkChangeEvent);
+
+		assertEquals(1, linkChangeEvent.getMdmLinks().size());
+		MdmLinkJson l = linkChangeEvent.getMdmLinks().get(0);
+		assertEquals(link.getGoldenResourcePid(), new IdDt(l.getGoldenResourceId()).getIdPartAsLong());
+		assertEquals(link.getSourcePid(), new IdDt(l.getSourceId()).getIdPartAsLong());
+	}
+
+	private MdmLink getLinkByTargetId(IBaseResource theResource) {
+		MdmLink example = new MdmLink();
+		example.setSourcePid(theResource.getIdElement().getIdPartAsLong());
+		return myMdmLinkDao.findAll(Example.of(example)).get(0);
+	}
+
+	@Test
+	public void testUpdateLinkChangeEvent() throws InterruptedException {
+		Patient patient1 = addExternalEID(buildJanePatient(), "eid-1");
+		myMdmHelper.createWithLatch(patient1);
+
+		MdmLinkEvent linkChangeEvent = myMdmHelper.getAfterMdmLatch().getLatchInvocationParameterOfType(MdmLinkEvent.class);
+		assertNotNull(linkChangeEvent);
+		assertEquals(1, linkChangeEvent.getMdmLinks().size());
+
+		MdmLinkJson link = linkChangeEvent.getMdmLinks().get(0);
+		assertEquals(patient1.getIdElement().toVersionless().getValueAsString(), link.getSourceId());
+		assertEquals(getLinkByTargetId(patient1).getGoldenResourcePid(), new IdDt(link.getGoldenResourceId()).getIdPartAsLong());
+		assertEquals(MdmMatchResultEnum.MATCH, link.getMatchResult());
+	}
+
+}

hapi-fhir-jpaserver-mdm/src/test/java/ca/uhn/fhir/jpa/mdm/interceptor/MdmStorageInterceptorIT.java

@@ -8,7 +8,9 @@ import ca.uhn.fhir.jpa.mdm.helper.MdmHelperConfig;
 import ca.uhn.fhir.jpa.mdm.helper.MdmHelperR4;
 import ca.uhn.fhir.jpa.searchparam.SearchParameterMap;
 import ca.uhn.fhir.mdm.model.CanonicalEID;
+import ca.uhn.fhir.mdm.model.MdmTransactionContext;
 import ca.uhn.fhir.mdm.rules.config.MdmSettings;
+import ca.uhn.fhir.model.primitive.IdDt;
 import ca.uhn.fhir.rest.api.server.IBundleProvider;
 import ca.uhn.fhir.rest.api.server.storage.ResourcePersistentId;
 import ca.uhn.fhir.rest.param.ReferenceParam;
@@ -26,6 +28,7 @@ import org.junit.jupiter.api.Test;
 import org.junit.jupiter.api.extension.RegisterExtension;
 import org.slf4j.Logger;
 import org.springframework.beans.factory.annotation.Autowired;
+import org.springframework.data.domain.Example;
 import org.springframework.test.annotation.DirtiesContext;
 import org.springframework.test.context.ContextConfiguration;
 
@@ -67,6 +70,12 @@ public class MdmStorageInterceptorIT extends BaseMdmR4Test {
 		assertLinkCount(1);
 	}
 
+	private MdmLink getLinkByTargetId(IBaseResource theResource) {
+		MdmLink example = new MdmLink();
+		example.setSourcePid(theResource.getIdElement().getIdPartAsLong());
+		return myMdmLinkDao.findAll(Example.of(example)).get(0);
+	}
+
 	@Test
 	public void testSearchExpandingInterceptorWorks() {
 		SearchParameterMap subject = new SearchParameterMap("subject", new ReferenceParam("Patient/123").setMdmExpand(true)).setLoadSynchronous(true);

hapi-fhir-server-mdm/src/main/java/ca/uhn/fhir/mdm/api/IMdmLink.java

@@ -0,0 +1,24 @@
+package ca.uhn.fhir.mdm.api;
+
+/*-
+ * #%L
+ * HAPI FHIR - Master Data Management
+ * %%
+ * Copyright (C) 2014 - 2021 Smile CDR, Inc.
+ * %%
+ * 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%
+ */
+
+public interface IMdmLink {
+}

hapi-fhir-server-mdm/src/main/java/ca/uhn/fhir/mdm/api/MdmLinkEvent.java

@@ -0,0 +1,56 @@
+package ca.uhn.fhir.mdm.api;
+
+/*-
+ * #%L
+ * HAPI FHIR - Master Data Management
+ * %%
+ * Copyright (C) 2014 - 2021 Smile CDR, Inc.
+ * %%
+ * 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 ca.uhn.fhir.model.api.IModelJson;
+import com.fasterxml.jackson.annotation.JsonProperty;
+import org.hl7.fhir.instance.model.api.IBaseResource;
+import org.hl7.fhir.instance.model.api.IIdType;
+
+import java.util.ArrayList;
+import java.util.HashSet;
+import java.util.List;
+import java.util.Set;
+
+public class MdmLinkEvent implements IModelJson {
+
+	private List<MdmLinkJson> myMdmLinks = new ArrayList<>();
+
+	public List<MdmLinkJson> getMdmLinks() {
+		return myMdmLinks;
+	}
+
+	public void setMdmLinks(List<MdmLinkJson> theMdmLinks) {
+		myMdmLinks = theMdmLinks;
+	}
+
+	public MdmLinkEvent addMdmLink(MdmLinkJson theMdmLink) {
+		getMdmLinks().add(theMdmLink);
+		return this;
+	}
+
+	@Override
+	public String toString() {
+		return "MdmLinkEvent{" +
+			"myMdmLinks=" + myMdmLinks +
+			'}';
+	}
+}

hapi-fhir-server-mdm/src/main/java/ca/uhn/fhir/mdm/api/MdmLinkJson.java

@@ -48,11 +48,15 @@ public class MdmLinkJson implements IModelJson {
 	@JsonProperty("version")
 	private String myVersion;
 
-	/** This link was created as a result of an eid match **/
+	/**
+	 * This link was created as a result of an eid match
+	 **/
 	@JsonProperty("eidMatch")
 	private Boolean myEidMatch;
 
-	/** This link created a new golden resource **/
+	/**
+	 * This link created a new golden resource
+	 **/
 	@JsonProperty("linkCreatedNewGoldenResource")
 	private Boolean myLinkCreatedNewResource;
 
@@ -62,6 +66,9 @@ public class MdmLinkJson implements IModelJson {
 	@JsonProperty("score")
 	private Double myScore;
 
+	@JsonProperty("ruleCount")
+	private Long myRuleCount;
+
 	public String getGoldenResourceId() {
 		return myGoldenResourceId;
 	}
@@ -160,4 +167,30 @@ public class MdmLinkJson implements IModelJson {
 		myScore = theScore;
 		return this;
 	}
+
+	public Long getRuleCount() {
+		return myRuleCount;
+	}
+
+	public void setRuleCount(Long theRuleCount) {
+		myRuleCount = theRuleCount;
+	}
+
+	@Override
+	public String toString() {
+		return "MdmLinkJson{" +
+			"myGoldenResourceId='" + myGoldenResourceId + '\'' +
+			", mySourceId='" + mySourceId + '\'' +
+			", myMatchResult=" + myMatchResult +
+			", myLinkSource=" + myLinkSource +
+			", myCreated=" + myCreated +
+			", myUpdated=" + myUpdated +
+			", myVersion='" + myVersion + '\'' +
+			", myEidMatch=" + myEidMatch +
+			", myLinkCreatedNewResource=" + myLinkCreatedNewResource +
+			", myVector=" + myVector +
+			", myScore=" + myScore +
+			", myRuleCount=" + myRuleCount +
+			'}';
+	}
 }

hapi-fhir-server-mdm/src/main/java/ca/uhn/fhir/mdm/model/MdmTransactionContext.java

@@ -20,8 +20,13 @@ package ca.uhn.fhir.mdm.model;
  * #L%
  */
 
+import ca.uhn.fhir.mdm.api.IMdmLink;
+import ca.uhn.fhir.mdm.api.MdmLinkEvent;
 import ca.uhn.fhir.rest.server.TransactionLogMessages;
 
+import java.util.ArrayList;
+import java.util.List;
+
 public class MdmTransactionContext {
 
 	public enum OperationType {
@@ -45,6 +50,8 @@ public class MdmTransactionContext {
 
 	private String myResourceType;
 
+	private List<IMdmLink> myMdmLinkEvents = new ArrayList<>();
+
 	public TransactionLogMessages getTransactionLogMessages() {
 		return myTransactionLogMessages;
 	}
@@ -92,4 +99,17 @@ public class MdmTransactionContext {
 	public void setResourceType(String myResourceType) {
 		this.myResourceType = myResourceType;
 	}
+
+	public List<IMdmLink> getMdmLinks() {
+		return myMdmLinkEvents;
+	}
+
+	public MdmTransactionContext addMdmLink(IMdmLink theMdmLinkEvent) {
+		getMdmLinks().add(theMdmLinkEvent);
+		return this;
+	}
+
+	public void setMdmLinks(List<IMdmLink> theMdmLinkEvents) {
+		myMdmLinkEvents = theMdmLinkEvents;
+	}
 }