/*
 $Id: NamedAccessNavigator.java,v 1.4 2006/02/05 21:47:41 elharo Exp $

 Copyright 2003 The Werken Company. All Rights Reserved.

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modification, are permitted provided that the following conditions are
met:

  * Redistributions of source code must retain the above copyright
    notice, this list of conditions and the following disclaimer.

  * Redistributions in binary form must reproduce the above copyright
    notice, this list of conditions and the following disclaimer in the
    documentation and/or other materials provided with the distribution.

  * Neither the name of the Jaxen Project nor the names of its
    contributors may be used to endorse or promote products derived
    from this software without specific prior written permission.

THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS
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 */
package org.orbeon.jaxen;

import java.util.Iterator;

/**
 * Interface for navigating around an arbitrary object model
 * accessing certain parts by name for performance.
 * <p>
 * This interface must only be implemented by those models that
 * can support this named access behavior.
 *
 * @author Stephen Colebourne
 */
public interface NamedAccessNavigator extends Navigator {

    /**
     * Retrieve an <code>Iterator</code> that returns the <code>child</code>
     * XPath axis where the names of the children match the supplied name
     * and optional namespace.
     * <p>
     * This method must only return element nodes with the correct name.
     * <p>
     * If the namespaceURI is null, no namespace should be used.
     * The prefix will never be null.
     *
     * @param contextNode  the origin context node
     * @param localName  the local name of the children to return, always present
     * @param namespacePrefix  the prefix of the namespace of the children to return
     * @param namespaceURI  the namespace URI of the children to return
     *
     * @return an Iterator capable of traversing the named children, or null if none
     *
     * @throws UnsupportedAxisException if the child axis is
     *         not supported by this object model
     */
    Iterator getChildAxisIterator(
        Object contextNode,
        String localName, String namespacePrefix, String namespaceURI)
            throws UnsupportedAxisException;

    /**
     * Retrieve an <code>Iterator</code> that returns the <code>attribute</code>
     * XPath axis where the names of the attributes match the supplied name
     * and optional namespace.
     * <p>
     * This method must only return attribute nodes with the correct name.
     * <p>
     * If the namespaceURI is null, no namespace should be used.
     * The prefix will never be null.
     *
     * @param contextNode  the origin context node
     * @param localName  the local name of the attributes to return, always present
     * @param namespacePrefix  the prefix of the namespace of the attributes to return
     * @param namespaceURI  the URI of the namespace of the attributes to return
     *
     * @return an Iterator capable of traversing the named attributes, or null if none
     *
     * @throws UnsupportedAxisException if the attribute axis is
     *         not supported by this object model
     */
    Iterator getAttributeAxisIterator(
        Object contextNode,
        String localName, String namespacePrefix, String namespaceURI)
            throws UnsupportedAxisException;

}