10.4Server Interceptors

 

There are many different Pointcuts available to server developers. In general, a server can be thought of as playing two roles: Server and Storage.

In the case of a Plain Server, HAPI FHIR itself performs the role of the Server and your Resource Provider classes perform the role of Storage.

In the case of a JPA Server, HAPI FHIR itself performs both roles. This means that SERVER_xxx Pointcuts may be intercepted by interceptors on any HAPI FHIR server. However, if you want to intercept STORAGE_xxx Pointcuts on a plain server, you will need to trigger them yourself.

10.4.1Example: Clearing Tags

 

The following example shows an interceptor that clears all tags, profiles, and security labels from a resource prior to storage in the JPA server.

/**
 * This is a simple interceptor for the JPA server that trims all tags, profiles, and security labels from
 * resources before they are saved.
 */
@Interceptor
public class TagTrimmingInterceptor {

   /** Handle creates */
   @Hook(Pointcut.STORAGE_PRESTORAGE_RESOURCE_CREATED)
   public void insert(IBaseResource theResource) {
      theResource.getMeta().getTag().clear();
      theResource.getMeta().getProfile().clear();
      theResource.getMeta().getSecurity().clear();
   }

   /** Handle updates */
   @Hook(Pointcut.STORAGE_PRESTORAGE_RESOURCE_UPDATED)
   public void update(IBaseResource theOldResource, IBaseResource theResource) {
      theResource.getMeta().getTag().clear();
      theResource.getMeta().getProfile().clear();
      theResource.getMeta().getSecurity().clear();
   }

}