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package org.w3c.dom.traversal;

import org.w3c.dom.Node;
import org.w3c.dom.DOMException;

NodeIterators 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 NodeIterators are created by calling DocumentTraversal.createNodeIterator().

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

Since:9, DOM Level 2
/** * <code>NodeIterators</code> are used to step through a set of nodes, e.g. * the set of nodes in a <code>NodeList</code>, the document subtree * governed by a particular <code>Node</code>, 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 <code>NodeIterator</code>. DOM Level 2 * specifies a single <code>NodeIterator</code> implementation for * document-order traversal of a document subtree. Instances of these * <code>NodeIterators</code> are created by calling * <code>DocumentTraversal</code><code>.createNodeIterator()</code>. * <p>See also the <a href='http://www.w3.org/TR/2000/REC-DOM-Level-2-Traversal-Range-20001113'>Document Object Model (DOM) Level 2 Traversal and Range Specification</a>. * @since 9, DOM Level 2 */
public interface NodeIterator {
The root node of the NodeIterator, as specified when it was created.
/** * The root node of the <code>NodeIterator</code>, as specified when it * was created. */
public Node getRoot();
This attribute determines which node types are presented via the NodeIterator. 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.
/** * This attribute determines which node types are presented via the * <code>NodeIterator</code>. The available set of constants is defined * in the <code>NodeFilter</code> interface. Nodes not accepted by * <code>whatToShow</code> will be skipped, but their children may still * be considered. Note that this skip takes precedence over the filter, * if any. */
public int getWhatToShow();
The NodeFilter used to screen nodes.
/** * The <code>NodeFilter</code> used to screen nodes. */
public NodeFilter getFilter();
The value of this flag determines whether the children of entity reference nodes are visible to the NodeIterator. If false, these children 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 NodeIterator. 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.
/** * The value of this flag determines whether the children of entity * reference nodes are visible to the <code>NodeIterator</code>. If * false, these children and their descendants will be rejected. Note * that this rejection takes precedence over <code>whatToShow</code> and * the filter. Also note that this is currently the only situation where * <code>NodeIterators</code> may reject a complete subtree rather than * skipping individual nodes. * <br> * <br> To produce a view of the document that has entity references * expanded and does not expose the entity reference node itself, use * the <code>whatToShow</code> flags to hide the entity reference node * and set <code>expandEntityReferences</code> to true when creating the * <code>NodeIterator</code>. To produce a view of the document that has * entity reference nodes but no entity expansion, use the * <code>whatToShow</code> flags to show the entity reference node and * set <code>expandEntityReferences</code> to false. */
public boolean getExpandEntityReferences();
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.
Throws:
  • DOMException – INVALID_STATE_ERR: Raised if this method is called after the detach method was invoked.
Returns:The next Node in the set being iterated over, or null if there are no more members in that set.
/** * Returns the next node in the set and advances the position of the * <code>NodeIterator</code> in the set. After a * <code>NodeIterator</code> is created, the first call to * <code>nextNode()</code> returns the first node in the set. * @return The next <code>Node</code> in the set being iterated over, or * <code>null</code> if there are no more members in that set. * @exception DOMException * INVALID_STATE_ERR: Raised if this method is called after the * <code>detach</code> method was invoked. */
public Node nextNode() throws DOMException;
Returns the previous node in the set and moves the position of the NodeIterator backwards in the set.
Throws:
  • DOMException – INVALID_STATE_ERR: Raised if this method is called after the detach method was invoked.
Returns:The previous Node in the set being iterated over, or null if there are no more members in that set.
/** * Returns the previous node in the set and moves the position of the * <code>NodeIterator</code> backwards in the set. * @return The previous <code>Node</code> in the set being iterated over, * or <code>null</code> if there are no more members in that set. * @exception DOMException * INVALID_STATE_ERR: Raised if this method is called after the * <code>detach</code> method was invoked. */
public Node previousNode() throws DOMException;
Detaches the NodeIterator from the set which it iterated over, releasing any computational resources and placing the NodeIterator in the INVALID state. After detach has been invoked, calls to nextNode or previousNode will raise the exception INVALID_STATE_ERR.
/** * Detaches the <code>NodeIterator</code> from the set which it iterated * over, releasing any computational resources and placing the * <code>NodeIterator</code> in the INVALID state. After * <code>detach</code> has been invoked, calls to <code>nextNode</code> * or <code>previousNode</code> will raise the exception * INVALID_STATE_ERR. */
public void detach(); }