ajaxdisplaytag.java

这是AJAX的一个HTML实现！ HTML标签AJAX的实现！

/**
 * Copyright 2005 Darren L. Spurgeon
 *
 * 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 net.sourceforge.ajaxtags.tags;

import net.sourceforge.ajaxtags.helpers.Logger;

import org.w3c.dom.Attr;
import org.w3c.dom.Document;
import org.w3c.dom.Node;
import org.w3c.dom.NodeList;

/**
 * Wraps a DisplayTag (http://displaytag.org) table, enabling AJAX capabilities.
 * In the process, anchors in the navigation are rewritten on the fly so that
 * the DisplayTag table refreshes within the same region on the page without a
 * full-page reload.
 * 
 * @author Darren Spurgeon
 * @version $Revision$ $Date: 2007/07/08 17:52:30 $ $Author: jenskapitza $
 */
public class AjaxDisplayTag extends AjaxAreaTag {

    /**
     * 
     */
    private static final long serialVersionUID = 1L;

    private String pagelinksClass;
    private String columnClass;

    /**
     * @return Returns the pagelinksClass.
     */
    public String getPagelinksClass() {
	return this.pagelinksClass;
    }

    /**
     * @param pagelinksClass
     *            The pagelinksClass to set.
     */
    public void setPagelinksClass(String pagelinksClass) {
	this.pagelinksClass = pagelinksClass;
    }

    /**
     * @return Returns the columnClass.
     */
    public String getColumnClass() {
	return this.columnClass;
    }

    /**
     * @param columnClass
     *            The columnClass to set.
     */
    public void setColumnClass(String columnClass) {
	this.columnClass = columnClass;
    }

    /**
     * @see javax.servlet.jsp.tagext.Tag#release()
     */
    @Override
    public void releaseTag() {
	super.releaseTag();
	this.pagelinksClass = "pagelinks";
	this.columnClass = "sortable";
    }

    public void rewriteAnchors0(Document document) {

	NodeList links = document.getElementsByTagName("a");
	for (int i = 0; i < links.getLength(); i++) {
	    Node link = links.item(i);
	    Node parent = link.getParentNode();
	    boolean rewrite = false;
	    if (parent.getNodeName().equals("span")) {
		Attr clazz = (Attr) parent.getAttributes()
			.getNamedItem("class");
		rewrite = clazz != null
			&& clazz.getNodeValue().contains(getPagelinksClass());
	    }

	    if (parent.getNodeName().equals("th")) {
		Attr clazz = (Attr) parent.getAttributes()
			.getNamedItem("class");

		rewrite = clazz != null
			&& clazz.getNodeValue().contains(getColumnClass());
	    }

	    if (rewrite) {
		rewriteLink(link, getId(), null);
	    }
	}
    }

    /**
     * @throws Exception
     * @see net.sourceforge.ajaxtags.tags.AjaxAreaTag#processContent(java.lang.String)
     */
    @Override
    protected String processContent(String content) {
	try {
	    Document doc = getDocument(content);
	    rewriteAnchors0(doc);
	    return toString(doc);
	} catch (Exception e) {
	    Logger.error("rewrite links faild < is the content xhtml? >", e);
	    Logger.error(content, null);
	    return content;
	}
    }

}