DefaultNamespaceContext.java

/*
 * Copyright 2001-2005 (C) MetaStuff, Ltd. All Rights Reserved.
 *
 * This software is open source.
 * See the bottom of this file for the licence.
 */

package org.dom4j.xpath;

import java.io.Serializable;

import org.dom4j.Document;
import org.dom4j.Element;
import org.dom4j.Namespace;
import org.dom4j.Node;

import org.jaxen.NamespaceContext;

/**
 * <p>
 * <code>DefaultNamespaceContext</code> implements a Jaxen NamespaceContext
 * such that a context node is used to determine the current XPath namespace
 * prefixes and namespace URIs available.
 * </p>
 * 
 * @author <a href="mailto:jstrachan@apache.org">James Strachan </a>
 */
public class DefaultNamespaceContext implements NamespaceContext, Serializable {
    private final Element element;

    public DefaultNamespaceContext(Element element) {
        this.element = element;
    }

    public static DefaultNamespaceContext create(Object node) {
        Element element = null;

        if (node instanceof Element) {
            element = (Element) node;
        } else if (node instanceof Document) {
            Document doc = (Document) node;
            element = doc.getRootElement();
        } else if (node instanceof Node) {
            element = ((Node) node).getParent();
        }

        if (element != null) {
            return new DefaultNamespaceContext(element);
        }

        return null;
    }

    public String translateNamespacePrefixToUri(String prefix) {
        if ((prefix != null) && (prefix.length() > 0)) {
            Namespace ns = element.getNamespaceForPrefix(prefix);

            if (ns != null) {
                return ns.getURI();
            }
        }

        return null;
    }
}

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 * Ltd. DOM4J is a registered trademark of MetaStuff, Ltd.
 * 
 * 5. Due credit should be given to the DOM4J Project - http://www.dom4j.org
 * 
 * THIS SOFTWARE IS PROVIDED BY METASTUFF, LTD. AND CONTRIBUTORS ``AS IS'' AND
 * ANY EXPRESSED OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
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 * 
 * Copyright 2001-2005 (C) MetaStuff, Ltd. All Rights Reserved.
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