org.xwiki.gwt.wysiwyg.client.plugin.link.LinkMetaDataExtractor.java Source code

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Here is the source code for org.xwiki.gwt.wysiwyg.client.plugin.link.LinkMetaDataExtractor.java

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/*
 * See the NOTICE file distributed with this work for additional
 * information regarding copyright ownership.
 *
 * This is free software; you can redistribute it and/or modify it
 * under the terms of the GNU Lesser General Public License as
 * published by the Free Software Foundation; either version 2.1 of
 * the License, or (at your option) any later version.
 *
 * This software is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
 * Lesser General Public License for more details.
 *
 * You should have received a copy of the GNU Lesser General Public
 * License along with this software; if not, write to the Free
 * Software Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA
 * 02110-1301 USA, or see the FSF site: http://www.fsf.org.
 */
package org.xwiki.gwt.wysiwyg.client.plugin.link;

import org.xwiki.gwt.dom.client.DOMUtils;
import org.xwiki.gwt.dom.client.Document;
import org.xwiki.gwt.dom.client.DocumentFragment;
import org.xwiki.gwt.dom.client.Element;
import org.xwiki.gwt.dom.client.InnerHTMLListener;
import org.xwiki.gwt.dom.client.Text;

import com.google.gwt.dom.client.Node;
import com.google.gwt.dom.client.NodeList;

/**
 * Analyzes the passed subtree and detects the link structures and transforms them in minimal HTML elements with
 * metafragments attached, so that the editor operates with minimal HTML.
 * 
 * @version $Id: 6b7e494da013291247a089fc04e61b0ebe122f33 $
 */
public class LinkMetaDataExtractor implements InnerHTMLListener {
    /**
     * {@inheritDoc}
     * 
     * @see InnerHTMLListener#onInnerHTMLChange(Element)
     */
    public void onInnerHTMLChange(Element parent) {
        // look up all images in this subtree
        NodeList<com.google.gwt.dom.client.Element> anchors = parent.getElementsByTagName("a");
        for (int i = 0; i < anchors.getLength(); i++) {
            Element anchor = (Element) anchors.getItem(i);
            processElement(anchor);
        }
    }

    /**
     * Processes the passed anchor looking for the wrapping span and neighbour comments to encapsulate it all in a
     * metafragment and leave only the anchor in the tree.
     * 
     * @param anchor the anchor element found
     */
    private void processElement(Element anchor) {
        // search for parent span and surrounding comments
        Element parentNode = anchor.getParentElement().cast();
        boolean foundWikiLink = parentNode != null && parentNode.getNodeName().equalsIgnoreCase("span");
        String spanClass = parentNode.getClassName();
        foundWikiLink &= spanClass.contains("wikilink") || spanClass.contains("wikicreatelink")
                || spanClass.contains("wikiexternallink");
        Node previousSibling = null;
        Node nextSibling = null;
        if (foundWikiLink) {
            // test the surrounding comments
            previousSibling = parentNode.getPreviousSibling();
            foundWikiLink &= previousSibling != null && previousSibling.getNodeType() == DOMUtils.COMMENT_NODE
                    && previousSibling.getNodeValue().startsWith("startwikilink");
            nextSibling = parentNode.getNextSibling();
            foundWikiLink &= nextSibling != null && nextSibling.getNodeType() == DOMUtils.COMMENT_NODE
                    && nextSibling.getNodeValue().startsWith("stopwikilink");
        }

        if (!foundWikiLink) {
            return;
        }

        DocumentFragment metaFragment = ((Document) anchor.getOwnerDocument()).createDocumentFragment();
        // put the end comments in
        metaFragment.appendChild(previousSibling);
        // create the placeholder and replace the anchor
        Text placeholder = (Text) ((Document) anchor.getOwnerDocument())
                .createTextNode(Element.INNER_HTML_PLACEHOLDER);
        parentNode.replaceChild(placeholder, anchor);
        // replace the parent node with the anchor
        parentNode.getParentElement().replaceChild(anchor, parentNode);
        // put parent node in meta fragment
        metaFragment.appendChild(parentNode);
        // put the end comment in
        metaFragment.appendChild(nextSibling);
        anchor.setMetaData(metaFragment);
    }
}