http://xml.apache.org/xalan-j/: Serializer to write out XML, HTML etc. as a stream of characters from an input DOM or from input SAX events. (The Apache Software Foundation) 
/*
 * 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.
 */
/*
 * $Id: DOMHelper.java 468655 2006-10-28 07:12:06Z minchau $
 */
package org.apache.xml.utils;

import java.util.Hashtable;
import java.util.Vector;

import javax.xml.XMLConstants;
import javax.xml.parsers.DocumentBuilder;
import javax.xml.parsers.DocumentBuilderFactory;
import javax.xml.parsers.ParserConfigurationException;

import org.apache.xml.dtm.ref.DTMNodeProxy;
import org.apache.xml.res.XMLErrorResources;
import org.apache.xml.res.XMLMessages;

import org.w3c.dom.Attr;
import org.w3c.dom.DOMImplementation;
import org.w3c.dom.Document;
import org.w3c.dom.DocumentType;
import org.w3c.dom.Element;
import org.w3c.dom.Entity;
import org.w3c.dom.NamedNodeMap;
import org.w3c.dom.Node;
import org.w3c.dom.Text;


Deprecated:Since the introduction of the DTM, this class will be removed.
This class provides a front-end to DOM implementations, providing
a number of utility functions that either aren't yet standardized
by the DOM spec or that are defined in optional DOM modules and
hence may not be present in all DOMs.
/**
 * @deprecated Since the introduction of the DTM, this class will be removed.
 * This class provides a front-end to DOM implementations, providing
 * a number of utility functions that either aren't yet standardized
 * by the DOM spec or that are defined in optional DOM modules and
 * hence may not be present in all DOMs.
 */
public class DOMHelper
{

  
DOM Level 1 did not have a standard mechanism for creating a new
Document object. This function provides a DOM-implementation-independent
abstraction for that for that concept. It's typically used when 
outputting a new DOM as the result of an operation.


TODO: This isn't directly compatable with DOM Level 2. 
The Level 2 createDocument call also creates the root 
element, and thus requires that you know what that element will be
before creating the Document. We should think about whether we want
to change this code, and the callers, so we can use the DOM's own 
method. (It's also possible that DOM Level 3 may relax this
sequence, but you may give up some intelligence in the DOM by
doing so; the intent was that knowing the document type and root
element might let the DOM automatically switch to a specialized
subclass for particular kinds of documents.)

Params:
  • isSecureProcessing – state of the secure processing feature.
Returns:The newly created DOM Document object, with no children, or
null if we can't find a DOM implementation that permits creating
new empty Documents.
/**
   * DOM Level 1 did not have a standard mechanism for creating a new
   * Document object. This function provides a DOM-implementation-independent
   * abstraction for that for that concept. It's typically used when 
   * outputting a new DOM as the result of an operation.
   * <p>
   * TODO: This isn't directly compatable with DOM Level 2. 
   * The Level 2 createDocument call also creates the root 
   * element, and thus requires that you know what that element will be
   * before creating the Document. We should think about whether we want
   * to change this code, and the callers, so we can use the DOM's own 
   * method. (It's also possible that DOM Level 3 may relax this
   * sequence, but you may give up some intelligence in the DOM by
   * doing so; the intent was that knowing the document type and root
   * element might let the DOM automatically switch to a specialized
   * subclass for particular kinds of documents.)
   *
   * @param isSecureProcessing state of the secure processing feature.
   * @return The newly created DOM Document object, with no children, or
   * null if we can't find a DOM implementation that permits creating
   * new empty Documents.
   */
  public static Document createDocument(boolean isSecureProcessing)
  {

    try
    {

      // Use an implementation of the JAVA API for XML Parsing 1.0 to
      // create a DOM Document node to contain the result.
      DocumentBuilderFactory dfactory = DocumentBuilderFactory.newInstance();

      dfactory.setNamespaceAware(true);
      dfactory.setValidating(true);
      
      if (isSecureProcessing)
      {
        try
        {
          dfactory.setFeature(XMLConstants.FEATURE_SECURE_PROCESSING, true);
        }
        catch (ParserConfigurationException pce) {}
      }
      
      DocumentBuilder docBuilder = dfactory.newDocumentBuilder();
      Document outNode = docBuilder.newDocument();

      return outNode;
    }
    catch (ParserConfigurationException pce)
    {
      throw new RuntimeException(
        XMLMessages.createXMLMessage(
          XMLErrorResources.ER_CREATEDOCUMENT_NOT_SUPPORTED, null));  //"createDocument() not supported in XPathContext!");

      // return null;
    }
  }

  
DOM Level 1 did not have a standard mechanism for creating a new
Document object. This function provides a DOM-implementation-independent
abstraction for that for that concept. It's typically used when 
outputting a new DOM as the result of an operation.

Returns:The newly created DOM Document object, with no children, or
null if we can't find a DOM implementation that permits creating
new empty Documents.
/**
   * DOM Level 1 did not have a standard mechanism for creating a new
   * Document object. This function provides a DOM-implementation-independent
   * abstraction for that for that concept. It's typically used when 
   * outputting a new DOM as the result of an operation.
   *
   * @return The newly created DOM Document object, with no children, or
   * null if we can't find a DOM implementation that permits creating
   * new empty Documents.
   */
  public static Document createDocument()
  {
    return createDocument(false);
  }
  
  
Tells, through the combination of the default-space attribute
on xsl:stylesheet, xsl:strip-space, xsl:preserve-space, and the
xml:space attribute, whether or not extra whitespace should be stripped
from the node.  Literal elements from template elements should
not be tested with this function.

Params:
  • textNode – A text node from the source tree.
Throws:
Returns:true if the text node should be stripped of extra whitespace.
@xsl.usageadvanced
/**
   * Tells, through the combination of the default-space attribute
   * on xsl:stylesheet, xsl:strip-space, xsl:preserve-space, and the
   * xml:space attribute, whether or not extra whitespace should be stripped
   * from the node.  Literal elements from template elements should
   * <em>not</em> be tested with this function.
   * @param textNode A text node from the source tree.
   * @return true if the text node should be stripped of extra whitespace.
   *
   * @throws javax.xml.transform.TransformerException
   * @xsl.usage advanced
   */
  public boolean shouldStripSourceNode(Node textNode)
          throws javax.xml.transform.TransformerException
  {

    // return (null == m_envSupport) ? false : m_envSupport.shouldStripSourceNode(textNode);
    return false;
  }

  
Supports the XPath function GenerateID by returning a unique
identifier string for any given DOM Node.


Warning: The base implementation uses the Node object's hashCode(),
which is NOT guaranteed to be unique. If that method hasn't been
overridden in this DOM ipmlementation, most Java implementions will
derive it from the object's address and should be OK... but if
your DOM uses a different definition of hashCode (eg hashing the
contents of the subtree), or if your DOM may have multiple objects
that represent a single Node in the data structure (eg via proxying),
you may need to find another way to assign a unique identifier.


Also, be aware that if nodes are destroyed and recreated, there is
an open issue regarding whether an ID may be reused. Currently
we're assuming that the input document is stable for the duration
of the XPath/XSLT operation, so this shouldn't arise in this context.


(DOM Level 3 is investigating providing a unique node "key", but
that won't help Level 1 and Level 2 implementations.)

Params:
  • node – whose identifier you want to obtain
Returns:a string which should be different for every Node object.
/**
   * Supports the XPath function GenerateID by returning a unique
   * identifier string for any given DOM Node.
   * <p>
   * Warning: The base implementation uses the Node object's hashCode(),
   * which is NOT guaranteed to be unique. If that method hasn't been
   * overridden in this DOM ipmlementation, most Java implementions will
   * derive it from the object's address and should be OK... but if
   * your DOM uses a different definition of hashCode (eg hashing the
   * contents of the subtree), or if your DOM may have multiple objects
   * that represent a single Node in the data structure (eg via proxying),
   * you may need to find another way to assign a unique identifier.
   * <p>
   * Also, be aware that if nodes are destroyed and recreated, there is
   * an open issue regarding whether an ID may be reused. Currently
   * we're assuming that the input document is stable for the duration
   * of the XPath/XSLT operation, so this shouldn't arise in this context.
   * <p>
   * (DOM Level 3 is investigating providing a unique node "key", but
   * that won't help Level 1 and Level 2 implementations.)
   *
   * @param node whose identifier you want to obtain
   *
   * @return a string which should be different for every Node object.
   */
  public String getUniqueID(Node node)
  {
    return "N" + Integer.toHexString(node.hashCode()).toUpperCase();
  }

  
Figure out whether node2 should be considered as being later
in the document than node1, in Document Order as defined
by the XPath model. This may not agree with the ordering defined
by other XML applications.


There are some cases where ordering isn't defined, and neither are
the results of this function -- though we'll generally return true.
TODO: Make sure this does the right thing with attribute nodes!!!

Params:
  • node1 – DOM Node to perform position comparison on.
  • node2 – DOM Node to perform position comparison on .
Returns:false if node2 comes before node1, otherwise return true.
You can think of this as 
(node1.documentOrderPosition <= node2.documentOrderPosition).
/**
   * Figure out whether node2 should be considered as being later
   * in the document than node1, in Document Order as defined
   * by the XPath model. This may not agree with the ordering defined
   * by other XML applications.
   * <p>
   * There are some cases where ordering isn't defined, and neither are
   * the results of this function -- though we'll generally return true.
   * 
   * TODO: Make sure this does the right thing with attribute nodes!!!
   *
   * @param node1 DOM Node to perform position comparison on.
   * @param node2 DOM Node to perform position comparison on .
   * 
   * @return false if node2 comes before node1, otherwise return true.
   * You can think of this as 
   * <code>(node1.documentOrderPosition &lt;= node2.documentOrderPosition)</code>.
   */
  public static boolean isNodeAfter(Node node1, Node node2)
  {
    if (node1 == node2 || isNodeTheSame(node1, node2))
      return true;

        // Default return value, if there is no defined ordering
    boolean isNodeAfter = true;
        
    Node parent1 = getParentOfNode(node1);
    Node parent2 = getParentOfNode(node2);          

    // Optimize for most common case
    if (parent1 == parent2 || isNodeTheSame(parent1, parent2))  // then we know they are siblings
    {
      if (null != parent1)
        isNodeAfter = isNodeAfterSibling(parent1, node1, node2);
      else
      {
                  // If both parents are null, ordering is not defined.
                  // We're returning a value in lieu of throwing an exception.
                  // Not a case we expect to arise in XPath, but beware if you
                  // try to reuse this method.
                  
                  // We can just fall through in this case, which allows us
                  // to hit the debugging code at the end of the function.
          //return isNodeAfter;
      }
    }
    else
    {

      // General strategy: Figure out the lengths of the two 
      // ancestor chains, reconcile the lengths, and look for
          // the lowest common ancestor. If that ancestor is one of
          // the nodes being compared, it comes before the other.
      // Otherwise perform a sibling compare. 
                //
                // NOTE: If no common ancestor is found, ordering is undefined
                // and we return the default value of isNodeAfter.
                
      // Count parents in each ancestor chain
      int nParents1 = 2, nParents2 = 2;  // include node & parent obtained above

      while (parent1 != null)
      {
        nParents1++;

        parent1 = getParentOfNode(parent1);
      }

      while (parent2 != null)
      {
        nParents2++;

        parent2 = getParentOfNode(parent2);
      }

          // Initially assume scan for common ancestor starts with
          // the input nodes.
      Node startNode1 = node1, startNode2 = node2;

      // If one ancestor chain is longer, adjust its start point
          // so we're comparing at the same depths
      if (nParents1 < nParents2)
      {
        // Adjust startNode2 to depth of startNode1
        int adjust = nParents2 - nParents1;

        for (int i = 0; i < adjust; i++)
        {
          startNode2 = getParentOfNode(startNode2);
        }
      }
      else if (nParents1 > nParents2)
      {
        // adjust startNode1 to depth of startNode2
        int adjust = nParents1 - nParents2;

        for (int i = 0; i < adjust; i++)
        {
          startNode1 = getParentOfNode(startNode1);
        }
      }

      Node prevChild1 = null, prevChild2 = null;  // so we can "back up"

      // Loop up the ancestor chain looking for common parent
      while (null != startNode1)
      {
        if (startNode1 == startNode2 || isNodeTheSame(startNode1, startNode2))  // common parent?
        {
          if (null == prevChild1)  // first time in loop?
          {

            // Edge condition: one is the ancestor of the other.
            isNodeAfter = (nParents1 < nParents2) ? true : false;

            break;  // from while loop
          }
          else 
          {
                        // Compare ancestors below lowest-common as siblings
            isNodeAfter = isNodeAfterSibling(startNode1, prevChild1,
                                             prevChild2);

            break;  // from while loop
          }
        }  // end if(startNode1 == startNode2)

                // Move up one level and try again
        prevChild1 = startNode1;
        startNode1 = getParentOfNode(startNode1);
        prevChild2 = startNode2;
        startNode2 = getParentOfNode(startNode2);
      }  // end while(parents exist to examine)
    }  // end big else (not immediate siblings)
        
        // WARNING: The following diagnostic won't report the early
        // "same node" case. Fix if/when needed.
        
    /* -- please do not remove... very useful for diagnostics --
    System.out.println("node1 = "+node1.getNodeName()+"("+node1.getNodeType()+")"+
    ", node2 = "+node2.getNodeName()
    +"("+node2.getNodeType()+")"+
    ", isNodeAfter = "+isNodeAfter); */
    return isNodeAfter;
  }  // end isNodeAfter(Node node1, Node node2)

  
Use DTMNodeProxy to determine whether two nodes are the same.

Params:
  • node1 – The first DOM node to compare.
  • node2 – The second DOM node to compare.
Returns:true if the two nodes are the same.
/**
   * Use DTMNodeProxy to determine whether two nodes are the same.
   * 
   * @param node1 The first DOM node to compare.
   * @param node2 The second DOM node to compare.
   * @return true if the two nodes are the same.
   */
  public static boolean isNodeTheSame(Node node1, Node node2)
  {
    if (node1 instanceof DTMNodeProxy && node2 instanceof DTMNodeProxy)
      return ((DTMNodeProxy)node1).equals((DTMNodeProxy)node2);
    else
      return (node1 == node2);
  }

  
Figure out if child2 is after child1 in document order.


Warning: Some aspects of "document order" are not well defined.
For example, the order of attributes is considered
meaningless in XML, and the order reported by our model will
be consistant for a given invocation but may not 
match that of either the source file or the serialized output.

Params:
  • parent – Must be the parent of both child1 and child2.
  • child1 – Must be the child of parent and not equal to child2.
  • child2 – Must be the child of parent and not equal to child1.
Returns:true if child 2 is after child1 in document order.
/**
   * Figure out if child2 is after child1 in document order.
   * <p>
   * Warning: Some aspects of "document order" are not well defined.
   * For example, the order of attributes is considered
   * meaningless in XML, and the order reported by our model will
   * be consistant for a given invocation but may not 
   * match that of either the source file or the serialized output.
   * 
   * @param parent Must be the parent of both child1 and child2.
   * @param child1 Must be the child of parent and not equal to child2.
   * @param child2 Must be the child of parent and not equal to child1.
   * @return true if child 2 is after child1 in document order.
   */
  private static boolean isNodeAfterSibling(Node parent, Node child1,
                                            Node child2)
  {

    boolean isNodeAfterSibling = false;
    short child1type = child1.getNodeType();
    short child2type = child2.getNodeType();

    if ((Node.ATTRIBUTE_NODE != child1type)
            && (Node.ATTRIBUTE_NODE == child2type))
    {

      // always sort attributes before non-attributes.
      isNodeAfterSibling = false;
    }
    else if ((Node.ATTRIBUTE_NODE == child1type)
             && (Node.ATTRIBUTE_NODE != child2type))
    {

      // always sort attributes before non-attributes.
      isNodeAfterSibling = true;
    }
    else if (Node.ATTRIBUTE_NODE == child1type)
    {
      NamedNodeMap children = parent.getAttributes();
      int nNodes = children.getLength();
      boolean found1 = false, found2 = false;

          // Count from the start until we find one or the other.
      for (int i = 0; i < nNodes; i++)
      {
        Node child = children.item(i);

        if (child1 == child || isNodeTheSame(child1, child))
        {
          if (found2)
          {
            isNodeAfterSibling = false;

            break;
          }

          found1 = true;
        }
        else if (child2 == child || isNodeTheSame(child2, child))
        {
          if (found1)
          {
            isNodeAfterSibling = true;

            break;
          }

          found2 = true;
        }
      }
    }
    else
    {
                // TODO: Check performance of alternate solution:
                // There are two choices here: Count from the start of
                // the document until we find one or the other, or count
                // from one until we find or fail to find the other.
                // Either can wind up scanning all the siblings in the worst
                // case, which on a wide document can be a lot of work but
                // is more typically is a short list. 
                // Scanning from the start involves two tests per iteration,
                // but it isn't clear that scanning from the middle doesn't
                // yield more iterations on average. 
                // We should run some testcases.
      Node child = parent.getFirstChild();
      boolean found1 = false, found2 = false;

      while (null != child)
      {

        // Node child = children.item(i);
        if (child1 == child || isNodeTheSame(child1, child))
        {
          if (found2)
          {
            isNodeAfterSibling = false;

            break;
          }

          found1 = true;
        }
        else if (child2 == child || isNodeTheSame(child2, child))
        {
          if (found1)
          {
            isNodeAfterSibling = true;

            break;
          }

          found2 = true;
        }

        child = child.getNextSibling();
      }
    }

    return isNodeAfterSibling;
  }  // end isNodeAfterSibling(Node parent, Node child1, Node child2)

  //==========================================================
  // SECTION: Namespace resolution
  //==========================================================

  
Get the depth level of this node in the tree (equals 1 for
a parentless node).

Params:
  • n – Node to be examined.
Returns:the number of ancestors, plus one
@xsl.usageinternal
/**
   * Get the depth level of this node in the tree (equals 1 for
   * a parentless node).
   *
   * @param n Node to be examined.
   * @return the number of ancestors, plus one
   * @xsl.usage internal
   */
  public short getLevel(Node n)
  {

    short level = 1;

    while (null != (n = getParentOfNode(n)))
    {
      level++;
    }

    return level;
  }

  
Given an XML Namespace prefix and a context in which the prefix
is to be evaluated, return the Namespace Name this prefix was 
bound to. Note that DOM Level 3 is expected to provide a version of
this which deals with the DOM's "early binding" behavior.
Default handling:

Params:
  • prefix – String containing namespace prefix to be resolved, 
without the ':' which separates it from the localname when used 
in a Node Name. The empty sting signifies the default namespace
at this point in the document.
  • namespaceContext – Element which provides context for resolution.
(We could extend this to work for other nodes by first seeking their
nearest Element ancestor.)
Returns:a String containing the Namespace URI which this prefix
represents in the specified context.
/**
   * Given an XML Namespace prefix and a context in which the prefix
   * is to be evaluated, return the Namespace Name this prefix was 
   * bound to. Note that DOM Level 3 is expected to provide a version of
   * this which deals with the DOM's "early binding" behavior.
   * 
   * Default handling:
   *
   * @param prefix String containing namespace prefix to be resolved, 
   * without the ':' which separates it from the localname when used 
   * in a Node Name. The empty sting signifies the default namespace
   * at this point in the document.
   * @param namespaceContext Element which provides context for resolution.
   * (We could extend this to work for other nodes by first seeking their
   * nearest Element ancestor.)
   *
   * @return a String containing the Namespace URI which this prefix
   * represents in the specified context.
   */
  public String getNamespaceForPrefix(String prefix, Element namespaceContext)
  {

    int type;
    Node parent = namespaceContext;
    String namespace = null;

    if (prefix.equals("xml"))
    {
      namespace = QName.S_XMLNAMESPACEURI; // Hardcoded, per Namespace spec
    }
        else if(prefix.equals("xmlns"))
    {
          // Hardcoded in the DOM spec, expected to be adopted by
          // Namespace spec. NOTE: Namespace declarations _must_ use
          // the xmlns: prefix; other prefixes declared as belonging
          // to this namespace will not be recognized and should
          // probably be rejected by parsers as erroneous declarations.
      namespace = "http://www.w3.org/2000/xmlns/"; 
    }
    else
    {
          // Attribute name for this prefix's declaration
          String declname=(prefix=="")
                        ? "xmlns"
                        : "xmlns:"+prefix;
                                           
          // Scan until we run out of Elements or have resolved the namespace
      while ((null != parent) && (null == namespace)
             && (((type = parent.getNodeType()) == Node.ELEMENT_NODE)
                 || (type == Node.ENTITY_REFERENCE_NODE)))
      {
        if (type == Node.ELEMENT_NODE)
        {
                        
                        // Look for the appropriate Namespace Declaration attribute,
                        // either "xmlns:prefix" or (if prefix is "") "xmlns".
                        // TODO: This does not handle "implicit declarations"
                        // which may be created when the DOM is edited. DOM Level
                        // 3 will define how those should be interpreted. But
                        // this issue won't arise in freshly-parsed DOMs.
                        
                // NOTE: declname is set earlier, outside the loop.
                        Attr attr=((Element)parent).getAttributeNode(declname);
                        if(attr!=null)
                        {
                namespace = attr.getNodeValue();
                break;
                        }
                }

        parent = getParentOfNode(parent);
      }
    }

    return namespace;
  }

  
An experiment for the moment.

/**
   * An experiment for the moment.
   */
  Hashtable m_NSInfos = new Hashtable();

  
Object to put into the m_NSInfos table that tells that a node has not been 
 processed, but has xmlns namespace decls.  
/** Object to put into the m_NSInfos table that tells that a node has not been 
   *  processed, but has xmlns namespace decls.  */
  protected static final NSInfo m_NSInfoUnProcWithXMLNS = new NSInfo(false,
                                                            true);

  
Object to put into the m_NSInfos table that tells that a node has not been 
 processed, but has no xmlns namespace decls.  
/** Object to put into the m_NSInfos table that tells that a node has not been 
   *  processed, but has no xmlns namespace decls.  */
  protected static final NSInfo m_NSInfoUnProcWithoutXMLNS = new NSInfo(false,
                                                               false);

  
Object to put into the m_NSInfos table that tells that a node has not been 
 processed, and has no xmlns namespace decls, and has no ancestor decls.  
/** Object to put into the m_NSInfos table that tells that a node has not been 
   *  processed, and has no xmlns namespace decls, and has no ancestor decls.  */
  protected static final NSInfo m_NSInfoUnProcNoAncestorXMLNS =
    new NSInfo(false, false, NSInfo.ANCESTORNOXMLNS);

  
Object to put into the m_NSInfos table that tells that a node has been 
 processed, and has xmlns namespace decls.  
/** Object to put into the m_NSInfos table that tells that a node has been 
   *  processed, and has xmlns namespace decls.  */
  protected static final NSInfo m_NSInfoNullWithXMLNS = new NSInfo(true,
                                                          true);

  
Object to put into the m_NSInfos table that tells that a node has been 
 processed, and has no xmlns namespace decls.  
/** Object to put into the m_NSInfos table that tells that a node has been 
   *  processed, and has no xmlns namespace decls.  */
  protected static final NSInfo m_NSInfoNullWithoutXMLNS = new NSInfo(true,
                                                             false);

  
Object to put into the m_NSInfos table that tells that a node has been 
 processed, and has no xmlns namespace decls. and has no ancestor decls.  
/** Object to put into the m_NSInfos table that tells that a node has been 
   *  processed, and has no xmlns namespace decls. and has no ancestor decls.  */
  protected static final NSInfo m_NSInfoNullNoAncestorXMLNS =
    new NSInfo(true, false, NSInfo.ANCESTORNOXMLNS);

  
Vector of node (odd indexes) and NSInfos (even indexes) that tell if 
 the given node is a candidate for ancestor namespace processing.  
/** Vector of node (odd indexes) and NSInfos (even indexes) that tell if 
   *  the given node is a candidate for ancestor namespace processing.  */
  protected Vector m_candidateNoAncestorXMLNS = new Vector();

  
Returns the namespace of the given node. Differs from simply getting
the node's prefix and using getNamespaceForPrefix in that it attempts
to cache some of the data in NSINFO objects, to avoid repeated lookup.
TODO: Should we consider moving that logic into getNamespaceForPrefix?

Params:
  • n – Node to be examined.
Returns:String containing the Namespace Name (uri) for this node.
Note that this is undefined for any nodes other than Elements and
Attributes.
/**
   * Returns the namespace of the given node. Differs from simply getting
   * the node's prefix and using getNamespaceForPrefix in that it attempts
   * to cache some of the data in NSINFO objects, to avoid repeated lookup.
   * TODO: Should we consider moving that logic into getNamespaceForPrefix?
   *
   * @param n Node to be examined.
   *
   * @return String containing the Namespace Name (uri) for this node.
   * Note that this is undefined for any nodes other than Elements and
   * Attributes.
   */
  public String getNamespaceOfNode(Node n)
  {

    String namespaceOfPrefix;
    boolean hasProcessedNS;
    NSInfo nsInfo;
    short ntype = n.getNodeType();

    if (Node.ATTRIBUTE_NODE != ntype)
    {
      Object nsObj = m_NSInfos.get(n);  // return value

      nsInfo = (nsObj == null) ? null : (NSInfo) nsObj;
      hasProcessedNS = (nsInfo == null) ? false : nsInfo.m_hasProcessedNS;
    }
    else
    {
      hasProcessedNS = false;
      nsInfo = null;
    }

    if (hasProcessedNS)
    {
      namespaceOfPrefix = nsInfo.m_namespace;
    }
    else
    {
      namespaceOfPrefix = null;

      String nodeName = n.getNodeName();
      int indexOfNSSep = nodeName.indexOf(':');
      String prefix;

      if (Node.ATTRIBUTE_NODE == ntype)
      {
        if (indexOfNSSep > 0)
        {
          prefix = nodeName.substring(0, indexOfNSSep);
        }
        else
        {

          // Attributes don't use the default namespace, so if 
          // there isn't a prefix, we're done.
          return namespaceOfPrefix;
        }
      }
      else
      {
        prefix = (indexOfNSSep >= 0)
                 ? nodeName.substring(0, indexOfNSSep) : "";
      }

      boolean ancestorsHaveXMLNS = false;
      boolean nHasXMLNS = false;

      if (prefix.equals("xml"))
      {
        namespaceOfPrefix = QName.S_XMLNAMESPACEURI;
      }
      else
      {
        int parentType;
        Node parent = n;

        while ((null != parent) && (null == namespaceOfPrefix))
        {
          if ((null != nsInfo)
                  && (nsInfo.m_ancestorHasXMLNSAttrs
                      == NSInfo.ANCESTORNOXMLNS))
          {
            break;
          }

          parentType = parent.getNodeType();

          if ((null == nsInfo) || nsInfo.m_hasXMLNSAttrs)
          {
            boolean elementHasXMLNS = false;

            if (parentType == Node.ELEMENT_NODE)
            {
              NamedNodeMap nnm = parent.getAttributes();

              for (int i = 0; i < nnm.getLength(); i++)
              {
                Node attr = nnm.item(i);
                String aname = attr.getNodeName();

                if (aname.charAt(0) == 'x')
                {
                  boolean isPrefix = aname.startsWith("xmlns:");

                  if (aname.equals("xmlns") || isPrefix)
                  {
                    if (n == parent)
                      nHasXMLNS = true;

                    elementHasXMLNS = true;
                    ancestorsHaveXMLNS = true;

                    String p = isPrefix ? aname.substring(6) : "";

                    if (p.equals(prefix))
                    {
                      namespaceOfPrefix = attr.getNodeValue();

                      break;
                    }
                  }
                }
              }
            }

            if ((Node.ATTRIBUTE_NODE != parentType) && (null == nsInfo)
                    && (n != parent))
            {
              nsInfo = elementHasXMLNS
                       ? m_NSInfoUnProcWithXMLNS : m_NSInfoUnProcWithoutXMLNS;

              m_NSInfos.put(parent, nsInfo);
            }
          }

          if (Node.ATTRIBUTE_NODE == parentType)
          {
            parent = getParentOfNode(parent);
          }
          else
          {
            m_candidateNoAncestorXMLNS.addElement(parent);
            m_candidateNoAncestorXMLNS.addElement(nsInfo);

            parent = parent.getParentNode();
          }

          if (null != parent)
          {
            Object nsObj = m_NSInfos.get(parent);  // return value

            nsInfo = (nsObj == null) ? null : (NSInfo) nsObj;
          }
        }

        int nCandidates = m_candidateNoAncestorXMLNS.size();

        if (nCandidates > 0)
        {
          if ((false == ancestorsHaveXMLNS) && (null == parent))
          {
            for (int i = 0; i < nCandidates; i += 2)
            {
              Object candidateInfo = m_candidateNoAncestorXMLNS.elementAt(i
                                       + 1);

              if (candidateInfo == m_NSInfoUnProcWithoutXMLNS)
              {
                m_NSInfos.put(m_candidateNoAncestorXMLNS.elementAt(i),
                              m_NSInfoUnProcNoAncestorXMLNS);
              }
              else if (candidateInfo == m_NSInfoNullWithoutXMLNS)
              {
                m_NSInfos.put(m_candidateNoAncestorXMLNS.elementAt(i),
                              m_NSInfoNullNoAncestorXMLNS);
              }
            }
          }

          m_candidateNoAncestorXMLNS.removeAllElements();
        }
      }

      if (Node.ATTRIBUTE_NODE != ntype)
      {
        if (null == namespaceOfPrefix)
        {
          if (ancestorsHaveXMLNS)
          {
            if (nHasXMLNS)
              m_NSInfos.put(n, m_NSInfoNullWithXMLNS);
            else
              m_NSInfos.put(n, m_NSInfoNullWithoutXMLNS);
          }
          else
          {
            m_NSInfos.put(n, m_NSInfoNullNoAncestorXMLNS);
          }
        }
        else
        {
          m_NSInfos.put(n, new NSInfo(namespaceOfPrefix, nHasXMLNS));
        }
      }
    }

    return namespaceOfPrefix;
  }

  
Returns the local name of the given node. If the node's name begins
with a namespace prefix, this is the part after the colon; otherwise
it's the full node name.

Params:
  • n – the node to be examined.
Returns:String containing the Local Name
/**
   * Returns the local name of the given node. If the node's name begins
   * with a namespace prefix, this is the part after the colon; otherwise
   * it's the full node name.
   *
   * @param n the node to be examined.
   *
   * @return String containing the Local Name
   */
  public String getLocalNameOfNode(Node n)
  {

    String qname = n.getNodeName();
    int index = qname.indexOf(':');

    return (index < 0) ? qname : qname.substring(index + 1);
  }

  
Returns the element name with the namespace prefix (if any) replaced
by the Namespace URI it was bound to. This is not a standard 
representation of a node name, but it allows convenient 
single-string comparison of the "universal" names of two nodes.

Params:
  • elem – Element to be examined.
See Also:
Returns:String in the form "namespaceURI:localname" if the node
belongs to a namespace, or simply "localname" if it doesn't.
/**
   * Returns the element name with the namespace prefix (if any) replaced
   * by the Namespace URI it was bound to. This is not a standard 
   * representation of a node name, but it allows convenient 
   * single-string comparison of the "universal" names of two nodes.
   *
   * @param elem Element to be examined.
   *
   * @return String in the form "namespaceURI:localname" if the node
   * belongs to a namespace, or simply "localname" if it doesn't.
   * @see #getExpandedAttributeName
   */
  public String getExpandedElementName(Element elem)
  {

    String namespace = getNamespaceOfNode(elem);

    return (null != namespace)
           ? namespace + ":" + getLocalNameOfNode(elem)
           : getLocalNameOfNode(elem);
  }

  
Returns the attribute name with the namespace prefix (if any) replaced
by the Namespace URI it was bound to. This is not a standard 
representation of a node name, but it allows convenient 
single-string comparison of the "universal" names of two nodes.

Params:
  • attr – Attr to be examined
See Also:
Returns:String in the form "namespaceURI:localname" if the node
belongs to a namespace, or simply "localname" if it doesn't.
/**
   * Returns the attribute name with the namespace prefix (if any) replaced
   * by the Namespace URI it was bound to. This is not a standard 
   * representation of a node name, but it allows convenient 
   * single-string comparison of the "universal" names of two nodes.
   *
   * @param attr Attr to be examined
   *
   * @return String in the form "namespaceURI:localname" if the node
   * belongs to a namespace, or simply "localname" if it doesn't.
   * @see #getExpandedElementName
   */
  public String getExpandedAttributeName(Attr attr)
  {

    String namespace = getNamespaceOfNode(attr);

    return (null != namespace)
           ? namespace + ":" + getLocalNameOfNode(attr)
           : getLocalNameOfNode(attr);
  }

  //==========================================================
  // SECTION: DOM Helper Functions
  //==========================================================

  
Tell if the node is ignorable whitespace. Note that this can
be determined only in the context of a DTD or other Schema,
and that DOM Level 2 has nostandardized DOM API which can
return that information.

Params:
  • node – Node to be examined
Deprecated:
Returns:CURRENTLY HARDCODED TO FALSE, but should return true if
and only if the node is of type Text, contains only whitespace,
and does not appear as part of the #PCDATA content of an element.
(Note that determining this last may require allowing for 
Entity References.)
/**
   * Tell if the node is ignorable whitespace. Note that this can
   * be determined only in the context of a DTD or other Schema,
   * and that DOM Level 2 has nostandardized DOM API which can
   * return that information.
   * @deprecated

   *
   * @param node Node to be examined
   *
   * @return CURRENTLY HARDCODED TO FALSE, but should return true if
   * and only if the node is of type Text, contains only whitespace,
   * and does not appear as part of the #PCDATA content of an element.
   * (Note that determining this last may require allowing for 
   * Entity References.)
   */
  public boolean isIgnorableWhitespace(Text node)
  {

    boolean isIgnorable = false;  // return value

    // TODO: I can probably do something to figure out if this 
    // space is ignorable from just the information in
    // the DOM tree.
        // -- You need to be able to distinguish whitespace
        // that is #PCDATA from whitespace that isn't.  That requires
        // DTD support, which won't be standardized until DOM Level 3.
    return isIgnorable;
  }

  
Get the first unparented node in the ancestor chain.

Params:
  • node – Starting node, to specify which chain to chase
Deprecated:
Returns:the topmost ancestor.
/**
   * Get the first unparented node in the ancestor chain.
   * @deprecated

   *
   * @param node Starting node, to specify which chain to chase
   *
   * @return the topmost ancestor.
   */
  public Node getRoot(Node node)
  {

    Node root = null;

    while (node != null)
    {
      root = node;
      node = getParentOfNode(node);
    }

    return root;
  }

  
Get the root node of the document tree, regardless of
whether or not the node passed in is a document node.


TODO: This doesn't handle DocumentFragments or "orphaned" subtrees
-- it's currently returning ownerDocument even when the tree is
not actually part of the main Document tree. We should either
rewrite the description to say that it finds the Document node,
or change the code to walk up the ancestor chain.

Params:
  • n – Node to be examined
Returns:the Document node. Note that this is not the correct answer
if n was (or was a child of) a DocumentFragment or an orphaned node,
as can arise if the DOM has been edited rather than being generated
by a parser.
/**
   * Get the root node of the document tree, regardless of
   * whether or not the node passed in is a document node.
   * <p>
   * TODO: This doesn't handle DocumentFragments or "orphaned" subtrees
   * -- it's currently returning ownerDocument even when the tree is
   * not actually part of the main Document tree. We should either
   * rewrite the description to say that it finds the Document node,
   * or change the code to walk up the ancestor chain.

   *
   * @param n Node to be examined
   *
   * @return the Document node. Note that this is not the correct answer
   * if n was (or was a child of) a DocumentFragment or an orphaned node,
   * as can arise if the DOM has been edited rather than being generated
   * by a parser.
   */
  public Node getRootNode(Node n)
  {
    int nt = n.getNodeType();
    return ( (Node.DOCUMENT_NODE == nt) || (Node.DOCUMENT_FRAGMENT_NODE == nt) ) 
           ? n : n.getOwnerDocument();
  }

  
Test whether the given node is a namespace decl node. In DOM Level 2
this can be done in a namespace-aware manner, but in Level 1 DOMs
it has to be done by testing the node name.

Params:
  • n – Node to be examined.
Returns:boolean -- true iff the node is an Attr whose name is 
"xmlns" or has the "xmlns:" prefix.
/**
   * Test whether the given node is a namespace decl node. In DOM Level 2
   * this can be done in a namespace-aware manner, but in Level 1 DOMs
   * it has to be done by testing the node name.
   *
   * @param n Node to be examined.
   *
   * @return boolean -- true iff the node is an Attr whose name is 
   * "xmlns" or has the "xmlns:" prefix.
   */
  public boolean isNamespaceNode(Node n)
  {

    if (Node.ATTRIBUTE_NODE == n.getNodeType())
    {
      String attrName = n.getNodeName();

      return (attrName.startsWith("xmlns:") || attrName.equals("xmlns"));
    }

    return false;
  }

  
Obtain the XPath-model parent of a DOM node -- ownerElement for Attrs,
parent for other nodes. 


Background: The DOM believes that you must be your Parent's
Child, and thus Attrs don't have parents. XPath said that Attrs
do have their owning Element as their parent. This function
bridges the difference, either by using the DOM Level 2 ownerElement
function or by using a "silly and expensive function" in Level 1
DOMs.


(There's some discussion of future DOMs generalizing ownerElement 
into ownerNode and making it work on all types of nodes. This
still wouldn't help the users of Level 1 or Level 2 DOMs)



Params:
  • node – Node whose XPath parent we want to obtain
Throws:
  • RuntimeException – if the Document has no root element.
This can't arise if the Document was created
via the DOM Level 2 factory methods, but is possible if other
mechanisms were used to obtain it
Returns:the parent of the node, or the ownerElement if it's an
Attr node, or null if the node is an orphan.
/**
   * Obtain the XPath-model parent of a DOM node -- ownerElement for Attrs,
   * parent for other nodes. 
   * <p>
   * Background: The DOM believes that you must be your Parent's
   * Child, and thus Attrs don't have parents. XPath said that Attrs
   * do have their owning Element as their parent. This function
   * bridges the difference, either by using the DOM Level 2 ownerElement
   * function or by using a "silly and expensive function" in Level 1
   * DOMs.
   * <p>
   * (There's some discussion of future DOMs generalizing ownerElement 
   * into ownerNode and making it work on all types of nodes. This
   * still wouldn't help the users of Level 1 or Level 2 DOMs)
   * <p>
   *
   * @param node Node whose XPath parent we want to obtain
   *
   * @return the parent of the node, or the ownerElement if it's an
   * Attr node, or null if the node is an orphan.
   *
   * @throws RuntimeException if the Document has no root element.
   * This can't arise if the Document was created
   * via the DOM Level 2 factory methods, but is possible if other
   * mechanisms were used to obtain it
   */
  public static Node getParentOfNode(Node node) throws RuntimeException
  {
    Node parent;
    short nodeType = node.getNodeType();

    if (Node.ATTRIBUTE_NODE == nodeType)
    {
      Document doc = node.getOwnerDocument();
          /*
      TBD:
      if(null == doc)
      {
        throw new RuntimeException(XSLMessages.createXPATHMessage(XPATHErrorResources.ER_CHILD_HAS_NO_OWNER_DOCUMENT, null));//"Attribute child does not have an owner document!");
      }
      */

          // Given how expensive the tree walk may be, we should first ask 
          // whether this DOM can answer the question for us. The additional
          // test does slow down Level 1 DOMs slightly. DOMHelper2, which
          // is currently specialized for Xerces, assumes it can use the
          // Level 2 solution. We might want to have an intermediate stage,
          // which would assume DOM Level 2 but not assume Xerces.
          //
          // (Shouldn't have to check whether impl is null in a compliant DOM,
          // but let's be paranoid for a moment...)
          DOMImplementation impl=doc.getImplementation();
          if(impl!=null && impl.hasFeature("Core","2.0"))
          {
                  parent=((Attr)node).getOwnerElement();
                  return parent;
          }

          // DOM Level 1 solution, as fallback. Hugely expensive. 

      Element rootElem = doc.getDocumentElement();

      if (null == rootElem)
      {
        throw new RuntimeException(
          XMLMessages.createXMLMessage(
            XMLErrorResources.ER_CHILD_HAS_NO_OWNER_DOCUMENT_ELEMENT,
            null));  //"Attribute child does not have an owner document element!");
      }

      parent = locateAttrParent(rootElem, node);

        }
    else
    {
      parent = node.getParentNode();

      // if((Node.DOCUMENT_NODE != nodeType) && (null == parent))
      // {
      //   throw new RuntimeException("Child does not have parent!");
      // }
    }

    return parent;
  }

  
Given an ID, return the element. This can work only if the document
is interpreted in the context of a DTD or Schema, since otherwise
we don't know which attributes are or aren't IDs.


Note that DOM Level 1 had no ability to retrieve this information.
DOM Level 2 introduced it but does not promise that it will be
supported in all DOMs; those which can't support it will always
return null.


TODO: getElementByID is currently unimplemented. Support DOM Level 2?

Params:
  • id – The unique identifier to be searched for.
  • doc – The document to search within.
Returns:CURRENTLY HARDCODED TO NULL, but it should be:
The node which has this unique identifier, or null if there
is no such node or this DOM can't reliably recognize it.
/**
   * Given an ID, return the element. This can work only if the document
   * is interpreted in the context of a DTD or Schema, since otherwise
   * we don't know which attributes are or aren't IDs.
   * <p>
   * Note that DOM Level 1 had no ability to retrieve this information.
   * DOM Level 2 introduced it but does not promise that it will be
   * supported in all DOMs; those which can't support it will always
   * return null.
   * <p>
   * TODO: getElementByID is currently unimplemented. Support DOM Level 2?
   *
   * @param id The unique identifier to be searched for.
   * @param doc The document to search within.
   * @return CURRENTLY HARDCODED TO NULL, but it should be:
   * The node which has this unique identifier, or null if there
   * is no such node or this DOM can't reliably recognize it.
   */
  public Element getElementByID(String id, Document doc)
  {
    return null;
  }

  
The getUnparsedEntityURI function returns the URI of the unparsed
entity with the specified name in the same document as the context
node (see [3.3 Unparsed Entities]). It returns the empty string if
there is no such entity.


XML processors may choose to use the System Identifier (if one
is provided) to resolve the entity, rather than the URI in the
Public Identifier. The details are dependent on the processor, and
we would have to support some form of plug-in resolver to handle
this properly. Currently, we simply return the System Identifier if
present, and hope that it a usable URI or that our caller can
map it to one.
TODO: Resolve Public Identifiers... or consider changing function name.


If we find a relative URI 
reference, XML expects it to be resolved in terms of the base URI 
of the document. The DOM doesn't do that for us, and it isn't 
entirely clear whether that should be done here; currently that's
pushed up to a higher levelof our application. (Note that DOM Level 
1 didn't store the document's base URI.)
TODO: Consider resolving Relative URIs.


(The DOM's statement that "An XML processor may choose to
completely expand entities before the structure model is passed
to the DOM" refers only to parsed entities, not unparsed, and hence
doesn't affect this function.)

Params:
  • name – A string containing the Entity Name of the unparsed
entity.
  • doc – Document node for the document to be searched.
Returns:String containing the URI of the Unparsed Entity, or an
empty string if no such entity exists.
/**
   * The getUnparsedEntityURI function returns the URI of the unparsed
   * entity with the specified name in the same document as the context
   * node (see [3.3 Unparsed Entities]). It returns the empty string if
   * there is no such entity.
   * <p>
   * XML processors may choose to use the System Identifier (if one
   * is provided) to resolve the entity, rather than the URI in the
   * Public Identifier. The details are dependent on the processor, and
   * we would have to support some form of plug-in resolver to handle
   * this properly. Currently, we simply return the System Identifier if
   * present, and hope that it a usable URI or that our caller can
   * map it to one.
   * TODO: Resolve Public Identifiers... or consider changing function name.
   * <p>
   * If we find a relative URI 
   * reference, XML expects it to be resolved in terms of the base URI 
   * of the document. The DOM doesn't do that for us, and it isn't 
   * entirely clear whether that should be done here; currently that's
   * pushed up to a higher levelof our application. (Note that DOM Level 
   * 1 didn't store the document's base URI.)
   * TODO: Consider resolving Relative URIs.
   * <p>
   * (The DOM's statement that "An XML processor may choose to
   * completely expand entities before the structure model is passed
   * to the DOM" refers only to parsed entities, not unparsed, and hence
   * doesn't affect this function.)
   *
   * @param name A string containing the Entity Name of the unparsed
   * entity.
   * @param doc Document node for the document to be searched.
   *
   * @return String containing the URI of the Unparsed Entity, or an
   * empty string if no such entity exists.
   */
  public String getUnparsedEntityURI(String name, Document doc)
  {

    String url = "";
    DocumentType doctype = doc.getDoctype();

    if (null != doctype)
    {
      NamedNodeMap entities = doctype.getEntities();
      if(null == entities)
        return url;
      Entity entity = (Entity) entities.getNamedItem(name);
      if(null == entity)
        return url;
      
      String notationName = entity.getNotationName();

      if (null != notationName)  // then it's unparsed
      {
        // The draft says: "The XSLT processor may use the public 
        // identifier to generate a URI for the entity instead of the URI 
        // specified in the system identifier. If the XSLT processor does 
        // not use the public identifier to generate the URI, it must use 
        // the system identifier; if the system identifier is a relative 
        // URI, it must be resolved into an absolute URI using the URI of 
        // the resource containing the entity declaration as the base 
        // URI [RFC2396]."
        // So I'm falling a bit short here.
        url = entity.getSystemId();

        if (null == url)
        {
          url = entity.getPublicId();
        }
        else
        {
          // This should be resolved to an absolute URL, but that's hard 
          // to do from here.
        }        
      }
    }

    return url;
  }

  
Support for getParentOfNode; walks a DOM tree until it finds
the Element which owns the Attr. This is hugely expensive, and
if at all possible you should use the DOM Level 2 Attr.ownerElement()
method instead.
 

The DOM Level 1 developers expected that folks would keep track
of the last Element they'd seen and could recover the info from
that source. Obviously that doesn't work very well if the only
information you've been presented with is the Attr. The DOM Level 2
getOwnerElement() method fixes that, but only for Level 2 and
later DOMs.

Params:
  • elem – Element whose subtree is to be searched for this Attr
  • attr – Attr whose owner is to be located.
Returns:the first Element whose attribute list includes the provided
attr. In modern DOMs, this will also be the only such Element. (Early
DOMs had some hope that Attrs might be sharable, but this idea has
been abandoned.)
/**
   * Support for getParentOfNode; walks a DOM tree until it finds
   * the Element which owns the Attr. This is hugely expensive, and
   * if at all possible you should use the DOM Level 2 Attr.ownerElement()
   * method instead.
   *  <p>
   * The DOM Level 1 developers expected that folks would keep track
   * of the last Element they'd seen and could recover the info from
   * that source. Obviously that doesn't work very well if the only
   * information you've been presented with is the Attr. The DOM Level 2
   * getOwnerElement() method fixes that, but only for Level 2 and
   * later DOMs.
   *
   * @param elem Element whose subtree is to be searched for this Attr
   * @param attr Attr whose owner is to be located.
   *
   * @return the first Element whose attribute list includes the provided
   * attr. In modern DOMs, this will also be the only such Element. (Early
   * DOMs had some hope that Attrs might be sharable, but this idea has
   * been abandoned.)
   */
  private static Node locateAttrParent(Element elem, Node attr)
  {

    Node parent = null;

        // This should only be called for Level 1 DOMs, so we don't have to
        // worry about namespace issues. In later levels, it's possible
        // for a DOM to have two Attrs with the same NodeName but
        // different namespaces, and we'd need to get getAttributeNodeNS...
        // but later levels also have Attr.getOwnerElement.
        Attr check=elem.getAttributeNode(attr.getNodeName());
        if(check==attr)
                parent = elem;

    if (null == parent)
    {
      for (Node node = elem.getFirstChild(); null != node;
              node = node.getNextSibling())
      {
        if (Node.ELEMENT_NODE == node.getNodeType())
        {
          parent = locateAttrParent((Element) node, attr);

          if (null != parent)
            break;
        }
      }
    }

    return parent;
  }

  
The factory object used for creating nodes
in the result tree.

/**
   * The factory object used for creating nodes
   * in the result tree.
   */
  protected Document m_DOMFactory = null;

  
Store the factory object required to create DOM nodes
in the result tree. In fact, that's just the result tree's
Document node...

Params:
  • domFactory – The DOM Document Node within whose context
the result tree will be built.
/**
   * Store the factory object required to create DOM nodes
   * in the result tree. In fact, that's just the result tree's
   * Document node...
   *
   * @param domFactory The DOM Document Node within whose context
   * the result tree will be built.
   */
  public void setDOMFactory(Document domFactory)
  {
    this.m_DOMFactory = domFactory;
  }

  
Retrieve the factory object required to create DOM nodes
in the result tree.

Returns:The result tree's DOM Document Node.
/**
   * Retrieve the factory object required to create DOM nodes
   * in the result tree.
   *
   * @return The result tree's DOM Document Node.
   */
  public Document getDOMFactory()
  {

    if (null == this.m_DOMFactory)
    {
      this.m_DOMFactory = createDocument();
    }

    return this.m_DOMFactory;
  }

  
Get the textual contents of the node. See
getNodeData(Node,FastStringBuffer) for discussion of how
whitespace nodes are handled.

Params:
  • node – DOM Node to be examined
See Also:
Returns:String containing a concatenation of all the 
textual content within that node.
/**
   * Get the textual contents of the node. See
   * getNodeData(Node,FastStringBuffer) for discussion of how
   * whitespace nodes are handled.
   *
   * @param node DOM Node to be examined
   * @return String containing a concatenation of all the 
   * textual content within that node. 
   * @see #getNodeData(Node,FastStringBuffer)
   * 
   */
  public static String getNodeData(Node node)
  {

    FastStringBuffer buf = StringBufferPool.get();
    String s;

    try
    {
      getNodeData(node, buf);

      s = (buf.length() > 0) ? buf.toString() : "";
    }
    finally
    {
      StringBufferPool.free(buf);
    }

    return s;
  }

  
Retrieve the text content of a DOM subtree, appending it into a
user-supplied FastStringBuffer object. Note that attributes are
not considered part of the content of an element.


There are open questions regarding whitespace stripping. 
Currently we make no special effort in that regard, since the standard
DOM doesn't yet provide DTD-based information to distinguish
whitespace-in-element-context from genuine #PCDATA. Note that we
should probably also consider xml:space if/when we address this.
DOM Level 3 may solve the problem for us.

Params:
  • node – Node whose subtree is to be walked, gathering the
contents of all Text or CDATASection nodes.
  • buf – FastStringBuffer into which the contents of the text
nodes are to be concatenated.
/**
   * Retrieve the text content of a DOM subtree, appending it into a
   * user-supplied FastStringBuffer object. Note that attributes are
   * not considered part of the content of an element.
   * <p>
   * There are open questions regarding whitespace stripping. 
   * Currently we make no special effort in that regard, since the standard
   * DOM doesn't yet provide DTD-based information to distinguish
   * whitespace-in-element-context from genuine #PCDATA. Note that we
   * should probably also consider xml:space if/when we address this.
   * DOM Level 3 may solve the problem for us.
   *
   * @param node Node whose subtree is to be walked, gathering the
   * contents of all Text or CDATASection nodes.
   * @param buf FastStringBuffer into which the contents of the text
   * nodes are to be concatenated.
   */
  public static void getNodeData(Node node, FastStringBuffer buf)
  {

    switch (node.getNodeType())
    {
    case Node.DOCUMENT_FRAGMENT_NODE :
    case Node.DOCUMENT_NODE :
    case Node.ELEMENT_NODE :
    {
      for (Node child = node.getFirstChild(); null != child;
              child = child.getNextSibling())
      {
        getNodeData(child, buf);
      }
    }
    break;
    case Node.TEXT_NODE :
    case Node.CDATA_SECTION_NODE :
      buf.append(node.getNodeValue());
      break;
    case Node.ATTRIBUTE_NODE :
      buf.append(node.getNodeValue());
      break;
    case Node.PROCESSING_INSTRUCTION_NODE :
      // warning(XPATHErrorResources.WG_PARSING_AND_PREPARING);        
      break;
    default :
      // ignore
      break;
    }
  }
}