Issue/591 DSF FHIR Server UI XML Rendering Broken for Reference Elements

dsf-fhir/dsf-fhir-server/src/main/java/dev/dsf/fhir/adapter/ThymeleafTemplateServiceImpl.java

@@ -357,7 +357,7 @@ private String toXml(MediaType mediaType, Resource resource) throws IOException
 
 		Matcher referenceUuidMatcher = XML_REFERENCE_UUID_PATTERN.matcher(content);
 		content = referenceUuidMatcher.replaceAll(result -> "&lt;reference value=\"<a href=\"" + result.group(1)
-				+ "?_format=html\">" + result.group(1) + "</a>\"&gt");
+				+ "?_format=html\">" + result.group(1) + "</a>\"/&gt");
 
 		return content;
 	}

dsf-fhir/dsf-fhir-server/src/test/java/dev/dsf/fhir/adapter/ThymeleafTemplateServiceTest.java

@@ -0,0 +1,139 @@
+/*
+ * Copyright 2018-2025 Heilbronn University of Applied Sciences
+ *
+ * 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.
+ */
+package dev.dsf.fhir.adapter;
+
+import static org.junit.Assert.assertEquals;
+
+import java.io.ByteArrayOutputStream;
+import java.nio.charset.StandardCharsets;
+import java.util.List;
+import java.util.UUID;
+import java.util.regex.Matcher;
+import java.util.regex.Pattern;
+
+import org.hl7.fhir.r4.model.Organization;
+import org.hl7.fhir.r4.model.OrganizationAffiliation;
+import org.hl7.fhir.r4.model.Reference;
+import org.junit.Test;
+import org.junit.runner.RunWith;
+import org.mockito.Mock;
+import org.mockito.Mockito;
+import org.mockito.junit.MockitoJUnitRunner;
+
+import ca.uhn.fhir.context.FhirContext;
+import dev.dsf.common.ui.theme.Theme;
+import jakarta.ws.rs.core.MediaType;
+import jakarta.ws.rs.core.MultivaluedHashMap;
+import jakarta.ws.rs.core.SecurityContext;
+import jakarta.ws.rs.core.UriInfo;
+
+@RunWith(MockitoJUnitRunner.class)
+public class ThymeleafTemplateServiceTest
+{
+	private static final String BASE_URL = "http://test.local";
+	private static final MediaType MEDIA_TYPE = MediaType.TEXT_HTML_TYPE;
+	private static final String SELF_CLOSING_TAG_REGEX = "&lt;reference value=\"<a href=\"\\w+/.*_format=html\">\\w+/.*</a>\"/&gt";
+	private static final Pattern SELF_CLOSING_TAG_PATTERN = Pattern.compile(SELF_CLOSING_TAG_REGEX);
+	private static final String NO_SELF_CLOSING_TAG_REGEX = "\"&lt;reference value=\"<a href=\"\\w+/.*_format=html\">\\w+/.*</a>\"&gt\";";
+	public static final Pattern NO_SELF_CLOSING_TAG_PATTERN = Pattern.compile(NO_SELF_CLOSING_TAG_REGEX);
+
+	private final FhirContext fhirContext = FhirContext.forR4();
+
+	@Mock
+	private Theme theme;
+
+	@Mock
+	private List<? extends ThymeleafContext> contexts;
+
+	@Mock
+	private UriInfo uriInfo;
+
+	@Mock
+	private SecurityContext securityContext;
+
+	@Test
+	public void testSelfClosingReferenceTags() throws Exception
+	{
+		Mockito.when(uriInfo.getPath()).thenReturn("");
+		Mockito.when(uriInfo.getQueryParameters()).thenReturn(new MultivaluedHashMap<>());
+
+		ThymeleafTemplateService thymeleafTemplateService = new ThymeleafTemplateServiceImpl(BASE_URL, theme,
+				fhirContext, contexts, false, false);
+
+		ByteArrayOutputStream xmlOutputStream = new ByteArrayOutputStream();
+		thymeleafTemplateService.writeTo(getExampleOrganization(), Organization.class, MEDIA_TYPE, uriInfo,
+				securityContext, xmlOutputStream);
+		String xmlContent = toString(xmlOutputStream.toByteArray());
+
+		assertEquals(1, getNumSelfClosingReferencesWithSlash(xmlContent));
+		assertEquals(0, getNumSelfClosingReferencesMissingSlash(xmlContent));
+		xmlOutputStream.close();
+
+		xmlOutputStream = new ByteArrayOutputStream();
+		thymeleafTemplateService.writeTo(getExampleOrganizationAffiliation(), OrganizationAffiliation.class, MEDIA_TYPE,
+				uriInfo, securityContext, xmlOutputStream);
+		xmlContent = toString(xmlOutputStream.toByteArray());
+
+		assertEquals(3, getNumSelfClosingReferencesWithSlash(xmlContent));
+		assertEquals(0, getNumSelfClosingReferencesMissingSlash(xmlContent));
+	}
+
+	private Organization getExampleOrganization()
+	{
+		Organization organization = new Organization();
+		organization.setId(UUID.randomUUID().toString());
+		organization.addEndpoint().setReference("Endpoint/" + UUID.randomUUID());
+		return organization;
+	}
+
+	private OrganizationAffiliation getExampleOrganizationAffiliation()
+	{
+		OrganizationAffiliation organizationAffiliation = new OrganizationAffiliation();
+		organizationAffiliation.setId(UUID.randomUUID().toString());
+		organizationAffiliation.setOrganization(new Reference("Organization/" + UUID.randomUUID()));
+		organizationAffiliation.setParticipatingOrganization(new Reference("Organization/" + UUID.randomUUID()));
+		organizationAffiliation.addEndpoint().setReference("Endpoint/" + UUID.randomUUID());
+
+		return organizationAffiliation;
+	}
+
+	private String toString(byte[] content)
+	{
+		return new String(content, StandardCharsets.UTF_8);
+	}
+
+	private int getNumSelfClosingReferencesWithSlash(String content)
+	{
+		int matches = 0;
+		Matcher matcher = SELF_CLOSING_TAG_PATTERN.matcher(content);
+
+		while (matcher.find())
+			matches++;
+
+		return matches;
+	}
+
+	private int getNumSelfClosingReferencesMissingSlash(String content)
+	{
+		int matches = 0;
+		Matcher matcher = NO_SELF_CLOSING_TAG_PATTERN.matcher(content);
+
+		while (matcher.find())
+			matches++;
+
+		return matches;
+	}
+}