Package org.apache.xml.dtm.ref

Class DTMNodeIterator

java.lang.Object
org.apache.xml.dtm.ref.DTMNodeIterator
All Implemented Interfaces:
NodeIterator
public class DTMNodeIterator
extends Object
implements NodeIterator
DTMNodeIterator gives us an implementation of the DTMNodeIterator which returns DOM nodes. Please note that this is not necessarily equivlaent to a DOM NodeIterator 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 NodeIterator's "maintain current position" response to document mutation.
  • Since our design for XPath NodeIterators builds a stateful filter directly into the traversal object, getNodeFilter() is not supported.

State: In progress!!

  • Constructor Summary

    Constructors
    Constructor Description
    DTMNodeIterator​(DTMIterator dtmIterator)
    Public constructor: Wrap a DTMNodeIterator around an existing and preconfigured DTMIterator

  • Method Summary

    Modifier and Type Method Description
    void detach()
    Detaches the NodeIterator from the set which it iterated over, releasing any computational resources and placing the iterator in the INVALID state.
    DTMIterator getDTMIterator()
    Access the wrapped DTMIterator.
    boolean getExpandEntityReferences()
    The value of this flag determines whether the children of entity reference nodes are visible to the iterator.
    NodeFilter getFilter()
    Return a handle to the filter used to screen nodes.
    Node getRoot()
    The root node of the NodeIterator, as specified when it was created.
    int getWhatToShow()
    Return a mask describing which node types are presented via the iterator.
    Node nextNode()
    Returns the next node in the set and advances the position of the NodeIterator in the set.
    Node previousNode()
    Returns the previous node in the set and moves the position of the NodeIterator backwards in the set.

    Methods inherited from class java.lang.Object

    clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

  • Constructor Details

    • DTMNodeIterator

      public DTMNodeIterator​(DTMIterator dtmIterator)
      Public constructor: Wrap a DTMNodeIterator around an existing and preconfigured DTMIterator

  • Method Details

    • getDTMIterator

      public DTMIterator getDTMIterator()
      Access the wrapped DTMIterator. I'm not sure whether anyone will need this or not, but let's write it and think about it.

    • detach

      public void detach()
      Detaches the NodeIterator from the set which it iterated over, releasing any computational resources and placing the iterator in the INVALID state.
      Specified by:
      detach in interface NodeIterator

    • getExpandEntityReferences

      public boolean getExpandEntityReferences()
      The value of this flag determines whether the children of entity reference nodes are visible to the iterator.
      Specified by:
      getExpandEntityReferences in interface NodeIterator
      Returns:
      false, always (the DTM model flattens entity references)

    • getFilter

      public NodeFilter getFilter()
      Return a handle to the filter used to screen nodes. This is ill-defined in Xalan's usage of Nodeiterator, where we have built stateful XPath-based filtering directly into the traversal object. We could return something which supports the NodeFilter interface and allows querying whether a given node would be permitted if it appeared as our next node, but in the current implementation that would be very complex -- and just isn't all that useful.
      Specified by:
      getFilter in interface NodeIterator
      Throws:
      DOMException - -- NOT_SUPPORTED_ERROR because I can't think of anything more useful to do in this case

    • getRoot

      public Node getRoot()
      Description copied from interface: NodeIterator
      The root node of the NodeIterator, as specified when it was created.
      Specified by:
      getRoot in interface NodeIterator
      Returns:
      The root node of the NodeIterator, as specified when it was created.

    • getWhatToShow

      public int getWhatToShow()
      Return a mask describing which node types are presented via the iterator.
      Specified by:
      getWhatToShow in interface NodeIterator

    • nextNode

      public Node nextNode() throws DOMException
      Description copied from interface: NodeIterator
      Returns the next node in the set and advances the position of the NodeIterator in the set. After a NodeIterator is created, the first call to nextNode() returns the first node in the set.
      Specified by:
      nextNode in interface NodeIterator
      Returns:
      the next node in the set and advance the position of the iterator in the set.
      Throws:
      DOMException - - INVALID_STATE_ERR Raised if this method is called after the detach method was invoked.

    • previousNode

      public Node previousNode()
      Description copied from interface: NodeIterator
      Returns the previous node in the set and moves the position of the NodeIterator backwards in the set.
      Specified by:
      previousNode in interface NodeIterator
      Returns:
      the next previous in the set and advance the position of the iterator in the set.
      Throws:
      DOMException - - INVALID_STATE_ERR Raised if this method is called after the detach method was invoked.