From 436e898819498ec59c9834c0c6b330a6e6b32dc7 Mon Sep 17 00:00:00 2001
From: Diederik Muylwyk <diederik.muylwyk@gmail.com>
Date: Fri, 17 Mar 2017 17:02:05 -0400
Subject: [PATCH] Added a hook for post-processing request details and
 validation results on failure.

---
 .../rest/server/interceptor/BaseValidatingInterceptor.java  | 6 ++++++
 src/changes/changes.xml                                     | 5 +++++
 2 files changed, 11 insertions(+)

diff --git a/hapi-fhir-base/src/main/java/ca/uhn/fhir/rest/server/interceptor/BaseValidatingInterceptor.java b/hapi-fhir-base/src/main/java/ca/uhn/fhir/rest/server/interceptor/BaseValidatingInterceptor.java
index e6170c7e00d..e22d7e0f6d0 100644
--- a/hapi-fhir-base/src/main/java/ca/uhn/fhir/rest/server/interceptor/BaseValidatingInterceptor.java
+++ b/hapi-fhir-base/src/main/java/ca/uhn/fhir/rest/server/interceptor/BaseValidatingInterceptor.java
@@ -267,6 +267,11 @@ abstract class BaseValidatingInterceptor<T> extends InterceptorAdapter {
 	 */
 	protected void postProcessResult(RequestDetails theRequestDetails, ValidationResult theValidationResult) { }
 
+	/**
+	 * Hook for subclasses on failure (e.g. add a response header to an incoming resource upon rejection).
+	 */
+	protected void postProcessResultOnFailure(RequestDetails theRequestDetails, ValidationResult theValidationResult) { }
+
 	/**
 	 * Note: May return null
 	 */
@@ -314,6 +319,7 @@ abstract class BaseValidatingInterceptor<T> extends InterceptorAdapter {
 		if (myFailOnSeverity != null) {
 			for (SingleValidationMessage next : validationResult.getMessages()) {
 				if (next.getSeverity().ordinal() >= myFailOnSeverity) {
+					postProcessResultOnFailure(theRequestDetails, validationResult);
 					fail(theRequestDetails, validationResult);
 					return validationResult;
 				}
diff --git a/src/changes/changes.xml b/src/changes/changes.xml
index e4fa4eff160..3448d43e454 100644
--- a/src/changes/changes.xml
+++ b/src/changes/changes.xml
@@ -202,6 +202,11 @@
 				the JPA database, improving performance of this operation. Thanks to
 				Joel Schneider for the pull request and analysis!
 			</action>
+			<action type="add">
+				A new post-processing hook for subclasses of BaseValidatingInterceptor is now
+				available. The hook exposes the request details on validation failure prior to throwing an
+				UnprocessableEntityException.
+			</action>
 		</release>
 		<release version="2.2" date="2016-12-20">
 			<action type="add">