SPR-3709

+ improved example to work with multi-nested declarations
+ used JDK 5 syntax
+ added documentation code into trunk (including unit test) for easier future reference

org.springframework.beans/src/test/java/com/foo/Component.java

@@ -0,0 +1,26 @@
+package com.foo;
+
+import java.util.ArrayList;
+import java.util.List;
+
+public class Component {
+	private String name;
+	private List<Component> components = new ArrayList<Component>();
+
+	// mmm, there is no setter method for the 'components'
+	public void addComponent(Component component) {
+		this.components.add(component);
+	}
+
+	public List<Component> getComponents() {
+		return components;
+	}
+
+	public String getName() {
+		return name;
+	}
+
+	public void setName(String name) {
+		this.name = name;
+	}
+}

org.springframework.beans/src/test/java/com/foo/ComponentBeanDefinitionParser.java

@@ -0,0 +1,52 @@
+package com.foo;
+
+import java.util.List;
+
+import org.springframework.beans.factory.config.BeanDefinition;
+import org.springframework.beans.factory.support.AbstractBeanDefinition;
+import org.springframework.beans.factory.support.BeanDefinitionBuilder;
+import org.springframework.beans.factory.support.ManagedList;
+import org.springframework.beans.factory.xml.AbstractBeanDefinitionParser;
+import org.springframework.beans.factory.xml.ParserContext;
+import org.springframework.util.xml.DomUtils;
+import org.w3c.dom.Element;
+
+public class ComponentBeanDefinitionParser extends AbstractBeanDefinitionParser {
+
+	protected AbstractBeanDefinition parseInternal(Element element,
+			ParserContext parserContext) {
+		return parseComponentElement(element);
+	}
+
+	private static AbstractBeanDefinition parseComponentElement(Element element) {
+		BeanDefinitionBuilder factory = BeanDefinitionBuilder
+				.rootBeanDefinition(ComponentFactoryBean.class);
+
+		factory.addPropertyValue("parent", parseComponent(element));
+
+		List<Element> childElements = DomUtils.getChildElementsByTagName(
+				element, "component");
+		if (childElements != null && childElements.size() > 0) {
+			parseChildComponents(childElements, factory);
+		}
+
+		return factory.getBeanDefinition();
+	}
+
+	private static BeanDefinition parseComponent(Element element) {
+		BeanDefinitionBuilder component = BeanDefinitionBuilder
+				.rootBeanDefinition(Component.class);
+		component.addPropertyValue("name", element.getAttribute("name"));
+		return component.getBeanDefinition();
+	}
+
+	private static void parseChildComponents(List<Element> childElements,
+			BeanDefinitionBuilder factory) {
+		ManagedList<BeanDefinition> children = new ManagedList<BeanDefinition>(
+				childElements.size());
+		for (Element element : childElements) {
+			children.add(parseComponentElement(element));
+		}
+		factory.addPropertyValue("children", children);
+	}
+}

org.springframework.beans/src/test/java/com/foo/ComponentBeanDefinitionParserTest.java

@@ -0,0 +1,74 @@
+/*
+ * Copyright 2006-2010 the original author or authors.
+ * 
+ * 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 com.foo;
+
+import java.util.List;
+
+import org.junit.AfterClass;
+import org.junit.BeforeClass;
+import org.junit.Test;
+import org.springframework.beans.factory.xml.XmlBeanFactory;
+import org.springframework.core.io.ClassPathResource;
+
+import static org.junit.Assert.*;
+import static org.hamcrest.CoreMatchers.*;
+
+/**
+ * @author Costin Leau
+ */
+public class ComponentBeanDefinitionParserTest {
+
+	private static XmlBeanFactory bf;
+
+	@BeforeClass
+	public static void setUpBeforeClass() throws Exception {
+		bf = new XmlBeanFactory(new ClassPathResource(
+				"com/foo/component-config.xml"));
+	}
+
+	@AfterClass
+	public static void tearDownAfterClass() throws Exception {
+		bf.destroySingletons();
+	}
+
+	private Component getBionicFamily() {
+		return bf.getBean("bionic-family", Component.class);
+	}
+
+	@Test
+	public void testBionicBasic() throws Exception {
+		Component cp = getBionicFamily();
+		assertThat("Bionic-1", equalTo(cp.getName()));
+	}
+
+	@Test
+	public void testBionicFirstLevelChildren() throws Exception {
+		Component cp = getBionicFamily();
+		List<Component> components = cp.getComponents();
+		assertThat(2, equalTo(components.size()));
+		assertThat("Mother-1", equalTo(components.get(0).getName()));
+		assertThat("Rock-1", equalTo(components.get(1).getName()));
+	}
+
+	@Test
+	public void testBionicSecondLevenChildren() throws Exception {
+		Component cp = getBionicFamily();
+		List<Component> components = cp.getComponents().get(0).getComponents();
+		assertThat(2, equalTo(components.size()));
+		assertThat("Karate-1", equalTo(components.get(0).getName()));
+		assertThat("Sport-1", equalTo(components.get(1).getName()));
+	}
+}

org.springframework.beans/src/test/java/com/foo/ComponentFactoryBean.java

@@ -0,0 +1,35 @@
+package com.foo;
+
+import java.util.List;
+
+import org.springframework.beans.factory.FactoryBean;
+
+public class ComponentFactoryBean implements FactoryBean<Component> {
+	private Component parent;
+	private List<Component> children;
+
+	public void setParent(Component parent) {
+		this.parent = parent;
+	}
+
+	public void setChildren(List<Component> children) {
+		this.children = children;
+	}
+
+	public Component getObject() throws Exception {
+		if (this.children != null && this.children.size() > 0) {
+			for (Component child : children) {
+				this.parent.addComponent(child);
+			}
+		}
+		return this.parent;
+	}
+
+	public Class<Component> getObjectType() {
+		return Component.class;
+	}
+
+	public boolean isSingleton() {
+		return true;
+	}
+}

org.springframework.beans/src/test/java/com/foo/ComponentNamespaceHandler.java

@@ -0,0 +1,10 @@
+package com.foo;
+
+import org.springframework.beans.factory.xml.NamespaceHandlerSupport;
+
+public class ComponentNamespaceHandler extends NamespaceHandlerSupport {
+	public void init() {
+		registerBeanDefinitionParser("component",
+				new ComponentBeanDefinitionParser());
+	}
+}