#229 - Added support for curies in HalEmbeddedBuilder.

HalEmbeddedBuilder now takes an optional CurieProvider to create namespaced rels for embeddededs.

Original pull request: #233.

Author: Jeff Stano

src/main/java/org/springframework/hateoas/hal/CurieProvider.java

@@ -25,6 +25,7 @@
  * 
  * @see http://tools.ietf.org/html/draft-kelly-json-hal#section-8.2
  * @author Oliver Gierke
+ * @author Jeff Stano
  * @since 0.9
  */
 public interface CurieProvider {
@@ -38,6 +39,16 @@ public interface CurieProvider {
 	 */
 	String getNamespacedRelFrom(Link link);
 
+	/**
+	 * Returns the rel to be rendered for the given rel. Will potentially prefix the rel but also might decide not to,
+	 * depending on the actual rel.
+	 * 
+	 * @param rel
+	 * @return
+	 * @since 0.17
+	 */
+	String getNamespacedRelFor(String rel);
+
 	/**
 	 * Returns an object to render as the base curie information. Implementations have to make sure, the retunred
 	 * instances renders as defined in the spec.

src/main/java/org/springframework/hateoas/hal/DefaultCurieProvider.java

@@ -28,6 +28,7 @@
  * Default implementation of {@link CurieProvider} rendering a single configurable {@link UriTemplate} based curie.
  * 
  * @author Oliver Gierke
+ * @author Jeff Stano
  * @since 0.9
  */
 public class DefaultCurieProvider implements CurieProvider {
@@ -65,8 +66,15 @@ public Collection<? extends Object> getCurieInformation(Links links) {
 	 */
 	@Override
 	public String getNamespacedRelFrom(Link link) {
+		return getNamespacedRelFor(link.getRel());
+	}
 
-		String rel = link.getRel();
+	/* 
+	 * (non-Javadoc)
+	 * @see org.springframework.hateoas.hal.CurieProvider#getNamespacedRelFrom(java.lang.String)
+	 */
+	@Override
+	public String getNamespacedRelFor(String rel) {
 
 		boolean prefixingNeeded = !IanaRels.isIanaRel(rel) && !rel.contains(":");
 		return prefixingNeeded ? String.format("%s:%s", curie.name, rel) : rel;

src/main/java/org/springframework/hateoas/hal/HalEmbeddedBuilder.java

@@ -42,6 +42,7 @@ class HalEmbeddedBuilder {
 
 	private final Map<String, Object> embeddeds = new HashMap<String, Object>();
 	private final RelProvider provider;
+	private final CurieProvider curieProvider;
 	private final EmbeddedWrappers wrappers;
 
 	/**
@@ -50,19 +51,20 @@ class HalEmbeddedBuilder {
 	 * @param provider can be {@literal null}.
 	 * @param preferCollectionRels whether to prefer to ask the provider for collection rels.
 	 */
-	public HalEmbeddedBuilder(RelProvider provider, boolean preferCollectionRels) {
+	public HalEmbeddedBuilder(RelProvider provider, CurieProvider curieProvider, boolean preferCollectionRels) {
 
 		Assert.notNull(provider, "Relprovider must not be null!");
 
 		this.provider = provider;
+		this.curieProvider = curieProvider;
 		this.wrappers = new EmbeddedWrappers(preferCollectionRels);
 	}
 
 	/**
 	 * Adds the given value to the embeddeds. Will skip doing so if the value is {@literal null} or the content of a
 	 * {@link Resource} is {@literal null}.
 	 * 
-	 * @param value can be {@literal null}.
+	 * @param source can be {@literal null}.
 	 */
 	public void add(Object source) {
 
@@ -116,6 +118,11 @@ private String getDefaultedRelFor(EmbeddedWrapper wrapper, boolean forCollection
 		Class<?> type = wrapper.getRelTargetType();
 
 		String rel = forCollection ? provider.getCollectionResourceRelFor(type) : provider.getItemResourceRelFor(type);
+
+		if (curieProvider != null) {
+			rel = curieProvider.getNamespacedRelFor(rel);
+		}
+
 		return rel == null ? DEFAULT_REL : rel;
 	}
 

src/main/java/org/springframework/hateoas/hal/Jackson2HalModule.java

@@ -238,18 +238,22 @@ public static class HalResourcesSerializer extends ContainerSerializer<Collectio
 
 		private final BeanProperty property;
 		private final RelProvider relProvider;
+		private final CurieProvider curieProvider;
 		private final boolean enforceEmbeddedCollections;
 
-		public HalResourcesSerializer(RelProvider relPorvider, boolean enforceEmbeddedCollections) {
-			this(null, relPorvider, enforceEmbeddedCollections);
+		public HalResourcesSerializer(RelProvider relPorvider, CurieProvider curieProvider,
+				boolean enforceEmbeddedCollections) {
+			this(null, relPorvider, curieProvider, enforceEmbeddedCollections);
 		}
 
-		public HalResourcesSerializer(BeanProperty property, RelProvider relProvider, boolean enforceEmbeddedCollections) {
+		public HalResourcesSerializer(BeanProperty property, RelProvider relProvider, CurieProvider curieProvider,
+				boolean enforceEmbeddedCollections) {
 
 			super(Collection.class, false);
 
 			this.property = property;
 			this.relProvider = relProvider;
+			this.curieProvider = curieProvider;
 			this.enforceEmbeddedCollections = enforceEmbeddedCollections;
 		}
 
@@ -263,7 +267,7 @@ public HalResourcesSerializer(BeanProperty property, RelProvider relProvider, bo
 		public void serialize(Collection<?> value, JsonGenerator jgen, SerializerProvider provider) throws IOException,
 				JsonGenerationException {
 
-			HalEmbeddedBuilder builder = new HalEmbeddedBuilder(relProvider, enforceEmbeddedCollections);
+			HalEmbeddedBuilder builder = new HalEmbeddedBuilder(relProvider, curieProvider, enforceEmbeddedCollections);
 
 			for (Object resource : value) {
 				builder.add(resource);
@@ -275,7 +279,7 @@ public void serialize(Collection<?> value, JsonGenerator jgen, SerializerProvide
 		@Override
 		public JsonSerializer<?> createContextual(SerializerProvider prov, BeanProperty property)
 				throws JsonMappingException {
-			return new HalResourcesSerializer(property, relProvider, enforceEmbeddedCollections);
+			return new HalResourcesSerializer(property, relProvider, curieProvider, enforceEmbeddedCollections);
 		}
 
 		@Override
@@ -600,7 +604,7 @@ public HalHandlerInstantiator(RelProvider resolver, CurieProvider curieProvider)
 		public HalHandlerInstantiator(RelProvider resolver, CurieProvider curieProvider, boolean enforceEmbeddedCollections) {
 
 			Assert.notNull(resolver, "RelProvider must not be null!");
-			this.instanceMap.put(HalResourcesSerializer.class, new HalResourcesSerializer(resolver,
+			this.instanceMap.put(HalResourcesSerializer.class, new HalResourcesSerializer(resolver, curieProvider,
 					enforceEmbeddedCollections));
 			this.instanceMap.put(HalLinkListSerializer.class, new HalLinkListSerializer(curieProvider));
 		}

src/test/java/org/springframework/hateoas/hal/DefaultCurieProviderUnitTest.java

@@ -72,4 +72,28 @@ public void prefixesNormalRels() {
 	public void doesNotPrefixQualifiedRels() {
 		assertThat(provider.getNamespacedRelFrom(new Link("http://amazon.com", "custom:rel")), is("custom:rel"));
 	}
+
+	/**
+	 * @see #229
+	 */
+	@Test
+	public void doesNotPrefixIanaRelsForRelAsString() {
+		assertThat(provider.getNamespacedRelFor("self"), is("self"));
+	}
+
+	/**
+	 * @see #229
+	 */
+	@Test
+	public void prefixesNormalRelsForRelAsString() {
+		assertThat(provider.getNamespacedRelFor("book"), is("acme:book"));
+	}
+
+	/**
+	 * @see #229
+	 */
+	@Test
+	public void doesNotPrefixQualifiedRelsForRelAsString() {
+		assertThat(provider.getNamespacedRelFor("custom:rel"), is("custom:rel"));
+	}
 }

src/test/java/org/springframework/hateoas/hal/DefaultCurieProviderUnitTests.java

@@ -25,28 +25,31 @@
 import org.junit.Before;
 import org.junit.Test;
 import org.springframework.hateoas.RelProvider;
+import org.springframework.hateoas.UriTemplate;
 import org.springframework.hateoas.core.EmbeddedWrappers;
 import org.springframework.hateoas.core.EvoInflectorRelProvider;
 
 /**
  * Unit tests for {@link HalEmbeddedBuilder}.
- * 
+ *
  * @author Oliver Gierke
  * @author Dietrich Schulten
  */
 public class HalEmbeddedBuilderUnitTest {
 
 	RelProvider provider;
+	CurieProvider curieProvider;
 
 	@Before
 	public void setUp() {
 		provider = new EvoInflectorRelProvider();
+		curieProvider = new DefaultCurieProvider("curie", new UriTemplate("http://localhost/{rel}"));
 	}
 
 	@Test
 	public void rendersSingleElementsWithSingleEntityRel() {
 
-		Map<String, Object> map = setUpBuilder("foo", 1L);
+		Map<String, Object> map = setUpBuilder(null, "foo", 1L);
 
 		assertThat(map.get("string"), is((Object) "foo"));
 		assertThat(map.get("long"), is((Object) 1L));
@@ -55,7 +58,7 @@ public void rendersSingleElementsWithSingleEntityRel() {
 	@Test
 	public void rendersMultipleElementsWithCollectionResourceRel() {
 
-		Map<String, Object> map = setUpBuilder("foo", "bar", 1L);
+		Map<String, Object> map = setUpBuilder(null, "foo", "bar", 1L);
 
 		assertThat(map.containsKey("string"), is(false));
 		assertThat(map.get("long"), is((Object) 1L));
@@ -68,7 +71,7 @@ public void rendersMultipleElementsWithCollectionResourceRel() {
 	@Test
 	public void correctlyPilesUpResourcesInCollectionRel() {
 
-		Map<String, Object> map = setUpBuilder("foo", "bar", "foobar", 1L);
+		Map<String, Object> map = setUpBuilder(null, "foo", "bar", "foobar", 1L);
 
 		assertThat(map.containsKey("string"), is(false));
 		assertHasValues(map, "strings", "foo", "bar", "foobar");
@@ -81,7 +84,7 @@ public void correctlyPilesUpResourcesInCollectionRel() {
 	@Test
 	public void forcesCollectionRelToBeUsedIfConfigured() {
 
-		HalEmbeddedBuilder builder = new HalEmbeddedBuilder(provider, true);
+		HalEmbeddedBuilder builder = new HalEmbeddedBuilder(provider, null, true);
 		builder.add("Sample");
 
 		assertThat(builder.asMap().get("string"), is(nullValue()));
@@ -96,7 +99,7 @@ public void doesNotPreferCollectionsIfRelAwareWasAdded() {
 
 		EmbeddedWrappers wrappers = new EmbeddedWrappers(false);
 
-		HalEmbeddedBuilder builder = new HalEmbeddedBuilder(provider, true);
+		HalEmbeddedBuilder builder = new HalEmbeddedBuilder(provider, null, true);
 		builder.add(wrappers.wrap("MyValue", "foo"));
 
 		assertThat(builder.asMap().get("foo"), is(instanceOf(String.class)));
@@ -107,9 +110,61 @@ public void doesNotPreferCollectionsIfRelAwareWasAdded() {
 	 */
 	@Test(expected = IllegalArgumentException.class)
 	public void rejectsNullRelProvider() {
-		new HalEmbeddedBuilder(null, false);
+		new HalEmbeddedBuilder(null, null, false);
+	}
+
+	/**
+	 * @see #229
+	 */
+	@Test
+	public void rendersSingleElementsWithSingleEntityRelWithCurieProvider() {
+
+		Map<String, Object> map = setUpBuilder(curieProvider, "foo", 1L);
+
+		assertThat(map.get("curie:string"), is((Object) "foo"));
+		assertThat(map.get("curie:long"), is((Object) 1L));
+	}
+
+	/**
+	 * @see #229
+	 */
+	@Test
+	public void rendersMultipleElementsWithCollectionResourceRelWithCurieProvider() {
+
+		Map<String, Object> map = setUpBuilder(curieProvider, "foo", "bar", 1L);
+
+		assertThat(map.containsKey("curie:string"), is(false));
+		assertThat(map.get("curie:long"), is((Object) 1L));
+		assertHasValues(map, "curie:strings", "foo", "bar");
+	}
+
+	/**
+	 * @see #229
+	 */
+	@Test
+	public void correctlyPilesUpResourcesInCollectionRelWithCurieprovider() {
+
+		Map<String, Object> map = setUpBuilder(curieProvider, "foo", "bar", "foobar", 1L);
+
+		assertThat(map.containsKey("curie:string"), is(false));
+		assertHasValues(map, "curie:strings", "foo", "bar", "foobar");
+		assertThat(map.get("curie:long"), is((Object) 1L));
+	}
+
+	/**
+	 * @see #229
+	 */
+	@Test
+	public void forcesCollectionRelToBeUsedIfConfiguredWithCurieProvider() {
+
+		HalEmbeddedBuilder builder = new HalEmbeddedBuilder(provider, curieProvider, true);
+		builder.add("Sample");
+
+		assertThat(builder.asMap().get("curie:string"), is(nullValue()));
+		assertHasValues(builder.asMap(), "curie:strings", "Sample");
 	}
 
+	@SuppressWarnings("unchecked")
 	private static void assertHasValues(Map<String, Object> source, String rel, Object... values) {
 
 		Object value = source.get(rel);
@@ -118,9 +173,9 @@ private static void assertHasValues(Map<String, Object> source, String rel, Obje
 		assertThat((List<Object>) value, Matchers.<List<Object>> allOf(hasSize(values.length), hasItems(values)));
 	}
 
-	private Map<String, Object> setUpBuilder(Object... values) {
+	private Map<String, Object> setUpBuilder(CurieProvider curieProvider, Object... values) {
 
-		HalEmbeddedBuilder builder = new HalEmbeddedBuilder(provider, false);
+		HalEmbeddedBuilder builder = new HalEmbeddedBuilder(provider, curieProvider, false);
 
 		for (Object value : values) {
 			builder.add(value);