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DOMHelper.javaAPI DocJava SE 5 API43585Fri Aug 26 14:56:04 BST 2005com.sun.org.apache.xml.internal.utils

DOMHelper

public class DOMHelper extends Object
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.

Fields Summary
Hashtable
m_NSInfos
An experiment for the moment.
protected static final NSInfo
m_NSInfoUnProcWithXMLNS
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_NSInfoUnProcWithoutXMLNS
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_NSInfoUnProcNoAncestorXMLNS
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_NSInfoNullWithXMLNS
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_NSInfoNullWithoutXMLNS
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_NSInfoNullNoAncestorXMLNS
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 Vector
m_candidateNoAncestorXMLNS
Vector of node (odd indexes) and NSInfos (even indexes) that tell if the given node is a candidate for ancestor namespace processing.
protected Document
m_DOMFactory
The factory object used for creating nodes in the result tree.
Constructors Summary
Methods Summary
public static org.w3c.dom.DocumentcreateDocument()
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.)

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.


    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);

      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;
    }
public org.w3c.dom.DocumentgetDOMFactory()
Retrieve the factory object required to create DOM nodes in the result tree.

return
The result tree's DOM Document Node.


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

    return this.m_DOMFactory;
public org.w3c.dom.ElementgetElementByID(java.lang.String id, org.w3c.dom.Document doc)
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?

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.

    return null;
public java.lang.StringgetExpandedAttributeName(org.w3c.dom.Attr attr)
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


    String namespace = getNamespaceOfNode(attr);

    return (null != namespace)
           ? namespace + ":" + getLocalNameOfNode(attr)
           : getLocalNameOfNode(attr);
public java.lang.StringgetExpandedElementName(org.w3c.dom.Element elem)
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


    String namespace = getNamespaceOfNode(elem);

    return (null != namespace)
           ? namespace + ":" + getLocalNameOfNode(elem)
           : getLocalNameOfNode(elem);
public shortgetLevel(org.w3c.dom.Node n)
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


    short level = 1;

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

    return level;
public java.lang.StringgetLocalNameOfNode(org.w3c.dom.Node n)
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


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

    return (index < 0) ? qname : qname.substring(index + 1);
public java.lang.StringgetNamespaceForPrefix(java.lang.String prefix, org.w3c.dom.Element namespaceContext)
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.


    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;
public java.lang.StringgetNamespaceOfNode(org.w3c.dom.Node n)
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.


                                                                             
     
  

    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;
public static java.lang.StringgetNodeData(org.w3c.dom.Node 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)


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

    try
    {
      getNodeData(node, buf);

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

    return s;
public static voidgetNodeData(org.w3c.dom.Node node, com.sun.org.apache.xml.internal.utils.FastStringBuffer buf)
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.

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.


    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;
    }
public static org.w3c.dom.NodegetParentOfNode(org.w3c.dom.Node node)
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)

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

    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;
public org.w3c.dom.NodegetRoot(org.w3c.dom.Node node)
Get the first unparented node in the ancestor chain.

deprecated
param
node Starting node, to specify which chain to chase
return
the topmost ancestor.


    Node root = null;

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

    return root;
public org.w3c.dom.NodegetRootNode(org.w3c.dom.Node n)
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.

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.

    int nt = n.getNodeType();
    return ( (Node.DOCUMENT_NODE == nt) || (Node.DOCUMENT_FRAGMENT_NODE == nt) ) 
           ? n : n.getOwnerDocument();
public java.lang.StringgetUniqueID(org.w3c.dom.Node node)
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.)

param
node whose identifier you want to obtain
return
a string which should be different for every Node object.

    return "N" + Integer.toHexString(node.hashCode()).toUpperCase();
public java.lang.StringgetUnparsedEntityURI(java.lang.String name, org.w3c.dom.Document doc)
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.)

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.


    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;
public booleanisIgnorableWhitespace(org.w3c.dom.Text node)
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.)


    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;
public booleanisNamespaceNode(org.w3c.dom.Node n)
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.


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

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

    return false;
public static booleanisNodeAfter(org.w3c.dom.Node node1, org.w3c.dom.Node node2)
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!!!

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 (node1.documentOrderPosition <= node2.documentOrderPosition).

    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;
private static booleanisNodeAfterSibling(org.w3c.dom.Node parent, org.w3c.dom.Node child1, org.w3c.dom.Node child2)
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.

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.


    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;
public static booleanisNodeTheSame(org.w3c.dom.Node node1, org.w3c.dom.Node node2)
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.

    if (node1 instanceof DTMNodeProxy && node2 instanceof DTMNodeProxy)
      return ((DTMNodeProxy)node1).equals((DTMNodeProxy)node2);
    else
      return (node1 == node2);
private static org.w3c.dom.NodelocateAttrParent(org.w3c.dom.Element elem, org.w3c.dom.Node attr)
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.

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.)


    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;
public voidsetDOMFactory(org.w3c.dom.Document domFactory)
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.


                                          
     
  
    this.m_DOMFactory = domFactory;
public booleanshouldStripSourceNode(org.w3c.dom.Node textNode)
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.

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


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