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DTMAxisIterNodeList.javaAPI DocJava SE 5 API4823Fri Aug 26 14:56:00 BST 2005com.sun.org.apache.xml.internal.dtm.ref

DTMAxisIterNodeList

public class DTMAxisIterNodeList extends DTMNodeListBase
DTMAxisNodeList gives us an implementation of the DOM's NodeList interface wrapped around a DTM Iterator. The author considers this something of an abominations, since NodeList was not intended to be a general purpose "list of nodes" API and is generally considered by the DOM WG to have be a mistake... but I'm told that some of the XPath/XSLT folks say they must have this solution. Please note that this is not necessarily equivlaent to a DOM NodeList operating over the same document. In particular:
  • If there are several Text nodes in logical succession (ie, across CDATASection and EntityReference boundaries), we will return only the first; the caller is responsible for stepping through them. (%REVIEW% Provide a convenience routine here to assist, pending proposed DOM Level 3 getAdjacentText() operation?)
  • Since the whole XPath/XSLT architecture assumes that the source document is not altered while we're working with it, we do not promise to implement the DOM NodeList's "live view" response to document mutation.

State: In progress!!

Fields Summary
private DTM
m_dtm
private DTMAxisIterator
m_iter
private IntVector
m_cachedNodes
private int
m_last
Constructors Summary
private DTMAxisIterNodeList()

    //================================================================
    // Methods unique to this class
public DTMAxisIterNodeList(DTM dtm, DTMAxisIterator dtmAxisIterator)
Public constructor: Wrap a DTMNodeList around an existing and preconfigured DTMAxisIterator

        if (dtmAxisIterator == null) {
            m_last = 0;
        } else {
            m_cachedNodes = new IntVector();
            m_dtm = dtm;
        }
        m_iter = dtmAxisIterator;
Methods Summary
public com.sun.org.apache.xml.internal.dtm.DTMAxisIteratorgetDTMAxisIterator()
Access the wrapped DTMIterator. I'm not sure whether anyone will need this or not, but let's write it and think about it.

        return m_iter;
public intgetLength()
The number of nodes in the list. The range of valid child node indices is 0 to length-1 inclusive.

        if (m_last == -1) {
            int node;
            while ((node = m_iter.next()) != DTMAxisIterator.END) {
                m_cachedNodes.addElement(node);
            }
            m_last = m_cachedNodes.size();
        }
        return m_last;
public org.w3c.dom.Nodeitem(int index)
Returns the indexth item in the collection. If index is greater than or equal to the number of nodes in the list, this returns null.

param
indexIndex into the collection.
return
The node at the indexth position in the NodeList, or null if that is not a valid index.

        if (m_iter != null) {
            int node;
            int count = m_cachedNodes.size();

            if (count > index) {
                node = m_cachedNodes.elementAt(index);
                return m_dtm.getNode(node);
            } else if (m_last == -1) {
                while (((node = m_iter.next()) != DTMAxisIterator.END)
                           && count <= index) {
                    m_cachedNodes.addElement(node);
                    count++;
                }
                if (node == DTMAxisIterator.END) {
                    m_last = count;
                } else {
                    return m_dtm.getNode(node);
                }
            }
        }
        return null;