DeleteInterceptor.java

import ca.uhn.fhir.interceptor.api.Hook;
import ca.uhn.fhir.interceptor.api.Pointcut;
import ca.uhn.fhir.interceptor.api.Interceptor;
import ca.uhn.fhir.jpa.api.dao.DaoRegistry;
import ca.uhn.fhir.jpa.api.dao.IFhirResourceDao;
import ca.uhn.fhir.jpa.partition.SystemRequestDetails;
import ca.uhn.fhir.jpa.subscription.channel.subscription.ISubscriptionDeliveryChannelNamer;
import ca.uhn.fhir.jpa.subscription.channel.subscription.SubscriptionChannelRegistry;
import ca.uhn.fhir.jpa.subscription.model.CanonicalSubscription;
import ca.uhn.fhir.jpa.subscription.model.ResourceDeliveryJsonMessage;
import ca.uhn.fhir.jpa.subscription.model.ResourceDeliveryMessage;
import ca.uhn.fhir.rest.server.messaging.BaseResourceMessage;
import org.hl7.fhir.instance.model.api.IBaseResource;
import org.hl7.fhir.r4.model.IdType;
import org.hl7.fhir.r4.model.Subscription;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.messaging.MessageChannel;

@Interceptor
public class DeleteInterceptor {

	@Autowired
	private DaoRegistry myDaoRegistry;
	@Autowired
	private SubscriptionCanonicalizer mySubscriptionCanonicalizer;
	@Autowired
	private ISubscriptionDeliveryChannelNamer mySubscriptionDeliveryChannelNamer;
	@Autowired
	private SubscriptionChannelRegistry mySubscriptionChannelRegistry;
	private volatile CanonicalSubscription myCanonicalSubscription;

	@Hook(Pointcut.STORAGE_PRECOMMIT_RESOURCE_DELETED)
	public void delete(IBaseResource theResource) {

		String subscriptionId = "Subscription/the-subscription-id"; // TODO: change this

		// Lazy load this once
		CanonicalSubscription canonicalSubscription = myCanonicalSubscription;
		if (canonicalSubscription == null) {
			IFhirResourceDao<Subscription> dao = myDaoRegistry.getResourceDao(Subscription.class);
			Subscription subscription = dao.read(new IdType(subscriptionId), new SystemRequestDetails());

			canonicalSubscription = mySubscriptionCanonicalizer.canonicalize(subscription);
			myCanonicalSubscription = canonicalSubscription;
		}
		
		// Create a deletion message
		ResourceDeliveryMessage deliveryMsg = new ResourceDeliveryMessage();
		deliveryMsg.setSubscription(canonicalSubscription);
		deliveryMsg.setPayloadId(theResource.getIdElement());
		deliveryMsg.setOperationType(BaseResourceMessage.OperationTypeEnum.DELETE);

		// Figure out the channel name and send a delivery message to it
		String channelName = mySubscriptionDeliveryChannelNamer.nameFromSubscription(canonicalSubscription);
		MessageChannel channel = mySubscriptionChannelRegistry.getDeliverySenderChannel(channelName);
		ResourceDeliveryJsonMessage wrappedMsg = new ResourceDeliveryJsonMessage(deliveryMsg);
		channel.send(wrappedMsg);
		
	}
	
	
}