org.w3c.dom.traversal
Interface NodeIterator

All Known Implementing Classes:

LocPathIterator, NodeSet, UnionPathIterator, XStatement

public interface NodeIterator

Iterators are used to step through a set of nodes, e.g. the set of nodes in a NodeList, the document subtree governed by a particular Node, the results of a query, or any other set of nodes. The set of nodes to be iterated is determined by the implementation of the NodeIterator. DOM Level 2 specifies a single NodeIterator implementation for document-order traversal of a document subtree. Instances of these iterators are created by calling DocumentTraversal .createNodeIterator().

See also the Document Object Model (DOM) Level 2 Traversal and Range Specification.

Since:

DOM Level 2

Method Summary

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

Method Detail

getRoot

public Node getRoot()

The root node of the NodeIterator, as specified when it was created.

getWhatToShow

public int getWhatToShow()

This attribute determines which node types are presented via the iterator. The available set of constants is defined in the NodeFilter interface. Nodes not accepted by whatToShow will be skipped, but their children may still be considered. Note that this skip takes precedence over the filter, if any.

getFilter

public NodeFilter getFilter()

The NodeFilter used to screen nodes.

getExpandEntityReferences

public boolean getExpandEntityReferences()

The value of this flag determines whether the children of entity reference nodes are visible to the iterator. If false, they and their descendants will be rejected. Note that this rejection takes precedence over whatToShow and the filter. Also note that this is currently the only situation where NodeIterators may reject a complete subtree rather than skipping individual nodes.

To produce a view of the document that has entity references expanded and does not expose the entity reference node itself, use the whatToShow flags to hide the entity reference node and set expandEntityReferences to true when creating the iterator. To produce a view of the document that has entity reference nodes but no entity expansion, use the whatToShow flags to show the entity reference node and set expandEntityReferences to false.

nextNode

public Node nextNode()
              throws DOMException

Returns the next node in the set and advances the position of the iterator in the set. After a NodeIterator is created, the first call to nextNode() returns the first node in the set.

Returns:

The next Node in the set being iterated over, or null if there are no more members in that set.

Throws:

DOMException - INVALID_STATE_ERR: Raised if this method is called after the detach method was invoked.

previousNode

public Node previousNode()
                  throws DOMException

Returns the previous node in the set and moves the position of the NodeIterator backwards in the set.

Returns:

The previous Node in the set being iterated over, or null if there are no more members in that set.

Throws:

DOMException - INVALID_STATE_ERR: Raised if this method is called after the detach method was invoked.

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. After detach has been invoked, calls to nextNode or previousNode will raise the exception INVALID_STATE_ERR.