parentresolver.java

Wicket一个开发Java Web应用程序框架。它使得开发web应用程序变得容易而轻松。 Wicket利用一个POJO data beans组件使得它可以与任何持久层技术相结合。

/*
 * Licensed to the Apache Software Foundation (ASF) under one or more
 * contributor license agreements.  See the NOTICE file distributed with
 * this work for additional information regarding copyright ownership.
 * The ASF licenses this file to You 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 org.apache.wicket.markup.resolver;

import org.apache.wicket.Component;
import org.apache.wicket.MarkupContainer;
import org.apache.wicket.markup.ComponentTag;
import org.apache.wicket.markup.MarkupStream;
import org.apache.wicket.markup.WicketTag;

/**
 * Some containers are transparent to the user (e.g. HtmlHeaderContainer or BodyOnLoadContainer) and
 * delegate component resolution to there parent.
 * 
 * @author Juergen Donnerstag
 */
public class ParentResolver implements IComponentResolver
{
	private static final long serialVersionUID = 1L;

	/**
	 * Try to resolve the tag, then create a component, add it to the container and render it.
	 * <p>
	 * Note: Special tags like &ltwicket:...&gt> and tags which id start with "_" are not resolved.
	 * 
	 * @see org.apache.wicket.markup.resolver.IComponentResolver#resolve(MarkupContainer,
	 *      MarkupStream, ComponentTag)
	 */
	public boolean resolve(final MarkupContainer container, final MarkupStream markupStream,
			final ComponentTag tag)
	{
		// Ignore special tags like _panel, _border, _extend etc.
		if ((tag instanceof WicketTag) || tag.isAutoComponentTag())
		{
			return false;
		}

		MarkupContainer parent = container;
		while ((parent != null) && (parent.isTransparentResolver()))
		{
			// Try to find the component with the parent component.
			parent = parent.getParent();
			if (parent != null)
			{
				Component component = parent.get(tag.getId());
				if (component != null)
				{
					component.render(markupStream);
					return true;
				}
			}
		}

		// If not yet found, restore the original parent and test if it
		// implement IComponentResolver
		parent = container.getParent();
		if (parent instanceof IComponentResolver)
		{
			return ((IComponentResolver)parent).resolve(container, markupStream, tag);
		}
		return false;
	}
}