Set text in a Node : DOM Edit « XML « Java






Set text in a Node

    
/*
 * Copyright (C) 2001  Christian Cryder [christianc@granitepeaks.com]
 *
 * This library 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 library 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 library; if not, write to the Free Software
 * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
 *
 * $Id: DOMUtil.java 114 2005-12-09 15:51:51Z christianc $
 */

import java.io.IOException;
import java.io.OutputStream;
import java.io.PrintWriter;
import java.util.Iterator;

import org.w3c.dom.Attr;
import org.w3c.dom.CharacterData;
import org.w3c.dom.Comment;
import org.w3c.dom.DOMException;
import org.w3c.dom.Element;
import org.w3c.dom.NamedNodeMap;
import org.w3c.dom.Node;
import org.w3c.dom.NodeList;
import org.w3c.dom.Text;

/**
 * DOM related utility functions.
 */
public class DOMUtil {

    private static byte[] sep = System.getProperty("line.separator").getBytes();

    /**
     * Find the first text descendent node of an element.
     * This recursively looks more than one level to search
     * for text in font nodes, etc.
     *
     * @param node The starting node for the search.
     * @return The text node or null if not found.
     */
    public static Text findFirstText(Node node) {
        if (node instanceof Text) return (Text) node;
        for (Node child = node.getFirstChild(); child!=null; child = child.getNextSibling()) {
            Text text = findFirstText(child);
            if (text!=null) return text;
        }
        return null;
    }

    /**
     * Gets the first text descendent node of an element.
     * This recursively looks more than one level to search
     * for text in font nodes, etc. Throws a DOMException
     * if the Text object is not found.
     *
     * @param node The starting node for the search.
     * @return The text node or null if not found.
     * @throws DOMException if the Text object is not found
     */
    public static Text getFirstText(Node node) {
        Text text = findFirstText(node);
        if (text==null) {
            String msg = "No child text mode found for element";
            String id = getID(node);
            throw new DOMException((short) -1, msg+(id!=null ? "; id=\""+id+"\"" : ""));
        }
        return text;
    }



    /**
     * Automatically set text in a Node. Basically we find the first
     * Text node beneath the current node and replace it with a
     * CDATASection for the incoming text. All other Text nodes are
     * removed. Throws a DOMException if it's illegal to add a Text
     * child to the particular node.
     *
     * @param node the starting node for the search.
     * @param text the text to be set
     * @param allowMarkupInText whether to allow markup in text to pass through unparsed
     * @return the updated node
     * @throws DOMException if the Text object is not found
     */
    public static Node setTextInNode(Node node, String text, boolean allowMarkupInText) {
        //start by setting the value in the first text node we find with a comment
        Comment comment = node.getOwnerDocument().createComment("");
        Node newNode = null;
        
        //csc_092701.1 - support both encoded/unencoded text
        if (allowMarkupInText) newNode = node.getOwnerDocument().createCDATASection(text);
        else newNode = node.getOwnerDocument().createTextNode(text);
//System.out.println ("newNode: "+newNode);
        
        Text textComp = DOMUtil.findFirstText((Element) node);
//System.out.println ("textComp:"+textComp);        
        if (textComp==null) {
            node.appendChild(comment);
        } else {
            Node parent = textComp.getParentNode();
            parent.replaceChild(comment, textComp);
        }
        
        //now remove all the rest of the text nodes
        removeAllTextNodes(node);        

        //now replace the comment with the newNode
        Node parent = comment.getParentNode();
        parent.replaceChild(newNode, comment);
//System.out.println ("parent:  "+parent);        
//System.out.println ("result:  "+DOMUtil.findFirstText((Element) parent));        
//DOMUtil.printStackTrace(parent.getOwnerDocument().getDocumentElement());
        return node;
    }
    
    /**
     * Remove all text nodes below this node
     *
     * @param node The starting node for the search.
     */
    public static void removeAllTextNodes(Node node) {
        if (node==null) return;
        if (!node.hasChildNodes()) return;
        NodeList nl = node.getChildNodes();
        for (int i=nl.getLength()-1; i>=0; i--) {
            Node n = (Node) nl.item(i);        
            if (n instanceof Text) node.removeChild(n);
            else removeAllTextNodes(n);
        }
    }
    
    /**
     * Given a Node name, return the "id" attribute if it exists.
     * If it does not exist, return null instead. This is basically
     * just a convenience method to cast the node to element and 
     * return the id from that.
     *
     * @param node the node name in question
     * @return the id value for the given node, if it exists. null if 
     *        doesn't
     */
    public static String getID(Node node) {
        return getID(node, null);
    }

    /**
     * Given a Node, return the "id" attribute if it exists.
     * If it does not exist, return nullResponse instead. This is basically
     * just a convenience method to cast the node to element and 
     * return the id from that.
     *
     * @param node the node in question
     * @param nullResponse the response to be returned if the id attribute
     *        does not exist
     * @return the id value for the given node, if it exists. null if 
     *        doesn't
     */
    public static String getID(Node node, String nullResponse) {
        String nodeName = nullResponse;
        if (node instanceof Element) {
            nodeName = ((Element) node).getAttribute("id");
        }
        return nodeName;
    }



    protected static void print(OutputStream out, String s) {
        if (out!=null) try {
            out.write(s.getBytes());
            out.write(sep);
        } catch (IOException ioe) {}
    }
}

   
    
    
    
  








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