Allow subclasses to access a snippet’s state

This commit updates each of the built-in snippet implementations to
provide protected getter methods for their fields. This allows
subclasses to access and work with the snippet’s state.

See gh-73

spring-restdocs-core/src/main/java/org/springframework/restdocs/hypermedia/LinksSnippet.java

@@ -47,8 +47,6 @@ public class LinksSnippet extends TemplatedSnippet {
 
 	private final Map<String, LinkDescriptor> descriptorsByRel = new LinkedHashMap<>();
 
-	private final Set<String> requiredRels = new HashSet<>();
-
 	private final LinkExtractor linkExtractor;
 
 	/**
@@ -79,9 +77,6 @@ public class LinksSnippet extends TemplatedSnippet {
 			Assert.hasText(descriptor.getRel());
 			Assert.hasText(descriptor.getDescription());
 			this.descriptorsByRel.put(descriptor.getRel(), descriptor);
-			if (!descriptor.isOptional()) {
-				this.requiredRels.add(descriptor.getRel());
-			}
 		}
 	}
 
@@ -105,7 +100,15 @@ public class LinksSnippet extends TemplatedSnippet {
 		Set<String> undocumentedRels = new HashSet<String>(actualRels);
 		undocumentedRels.removeAll(this.descriptorsByRel.keySet());
 
-		Set<String> missingRels = new HashSet<String>(this.requiredRels);
+		Set<String> requiredRels = new HashSet<>();
+		for (Entry<String, LinkDescriptor> relAndDescriptor : this.descriptorsByRel
+				.entrySet()) {
+			if (!relAndDescriptor.getValue().isOptional()) {
+				requiredRels.add(relAndDescriptor.getKey());
+			}
+		}
+
+		Set<String> missingRels = new HashSet<String>(requiredRels);
 		missingRels.removeAll(actualRels);
 
 		if (!undocumentedRels.isEmpty() || !missingRels.isEmpty()) {
@@ -133,4 +136,14 @@ public class LinksSnippet extends TemplatedSnippet {
 		return model;
 	}
 
+	/**
+	 * Returns a {@code Map} of {@link LinkDescriptor LinkDescriptors} keyed by their
+	 * {@link LinkDescriptor#getRel() rels}.
+	 * 
+	 * @return the link descriptors
+	 */
+	protected final Map<String, LinkDescriptor> getDescriptorsByRel() {
+		return this.descriptorsByRel;
+	}
+
 }

spring-restdocs-core/src/main/java/org/springframework/restdocs/payload/AbstractFieldsSnippet.java

@@ -146,4 +146,14 @@ public abstract class AbstractFieldsSnippet extends TemplatedSnippet {
 	 */
 	protected abstract byte[] getContent(Operation operation) throws IOException;
 
+	/**
+	 * Returns the list of {@link FieldDescriptor FieldDescriptors} that will be used to
+	 * generate the documentation.
+	 * 
+	 * @return the field descriptors
+	 */
+	protected final List<FieldDescriptor> getFieldDescriptors() {
+		return this.fieldDescriptors;
+	}
+
 }

spring-restdocs-core/src/main/java/org/springframework/restdocs/request/AbstractParametersSnippet.java

@@ -94,4 +94,15 @@ public abstract class AbstractParametersSnippet extends TemplatedSnippet {
 	protected abstract void verificationFailed(Set<String> undocumentedParameters,
 			Set<String> missingParameters);
 
+	/**
+	 * Returns a {@code Map} of {@link ParameterDescriptor ParameterDescriptors} that will
+	 * be used to generate the documentation key by their
+	 * {@link ParameterDescriptor#getName()}.
+	 * 
+	 * @return the map of path descriptors
+	 */
+	protected final Map<String, ParameterDescriptor> getFieldDescriptors() {
+		return this.descriptorsByName;
+	}
+
 }

spring-restdocs-core/src/main/java/org/springframework/restdocs/snippet/TemplatedSnippet.java

@@ -81,4 +81,23 @@ public abstract class TemplatedSnippet implements Snippet {
 	 */
 	protected abstract Map<String, Object> createModel(Operation operation);
 
+	/**
+	 * Returns the additional attributes that will be included in the model during
+	 * template rendering.
+	 * 
+	 * @return the additional attributes
+	 */
+	protected final Map<String, Object> getAttributes() {
+		return this.attributes;
+	}
+
+	/**
+	 * Returns the name of the snippet that will be created.
+	 * 
+	 * @return the snippet name
+	 */
+	protected final String getSnippetName() {
+		return this.snippetName;
+	}
+
 }