/*
* Copyright 1999-2004 The Apache Software Foundation.
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
/*
* $Id: PrefixResolverDefault.java,v 1.2.4.1 2005/09/15 08:15:51 suresh_emailid Exp $
*/
package com.sun.org.apache.xml.internal.utils;
import org.w3c.dom.NamedNodeMap;
import org.w3c.dom.Node;
/**
* This class implements a generic PrefixResolver that
* can be used to perform prefix-to-namespace lookup
* for the XPath object.
* @xsl.usage general
*/
public class PrefixResolverDefault implements PrefixResolver
{
/**
* The context to resolve the prefix from, if the context
* is not given.
*/
Node m_context;
/**
* Construct a PrefixResolverDefault object.
* @param xpathExpressionContext The context from
* which XPath expression prefixes will be resolved.
* Warning: This will not work correctly if xpathExpressionContext
* is an attribute node.
*/
public PrefixResolverDefault(Node xpathExpressionContext)
{
m_context = xpathExpressionContext;
}
/**
* Given a namespace, get the corrisponding prefix. This assumes that
* the PrevixResolver hold's it's own namespace context, or is a namespace
* context itself.
* @param prefix Prefix to resolve.
* @return Namespace that prefix resolves to, or null if prefix
* is not bound.
*/
public String getNamespaceForPrefix(String prefix)
{
return getNamespaceForPrefix(prefix, m_context);
}
/**
* Given a namespace, get the corrisponding prefix.
* Warning: This will not work correctly if namespaceContext
* is an attribute node.
* @param prefix Prefix to resolve.
* @param namespaceContext Node from which to start searching for a
* xmlns attribute that binds a prefix to a namespace.
* @return Namespace that prefix resolves to, or null if prefix
* is not bound.
*/
public String getNamespaceForPrefix(String prefix,
org.w3c.dom.Node namespaceContext)
{
Node parent = namespaceContext;
String namespace = null;
if (prefix.equals("xml"))
{
namespace = Constants.S_XMLNAMESPACEURI;
}
else
{
int type;
while ((null != parent) && (null == namespace)
&& (((type = parent.getNodeType()) == Node.ELEMENT_NODE)
|| (type == Node.ENTITY_REFERENCE_NODE)))
{
if (type == Node.ELEMENT_NODE)
{
if (parent.getNodeName().indexOf(prefix+":") == 0)
return parent.getNamespaceURI();
NamedNodeMap nnm = parent.getAttributes();
for (int i = 0; i < nnm.getLength(); i++)
{
Node attr = nnm.item(i);
String aname = attr.getNodeName();
boolean isPrefix = aname.startsWith("xmlns:");
if (isPrefix || aname.equals("xmlns"))
{
int index = aname.indexOf(':');
String p = isPrefix ? aname.substring(index + 1) : "";
if (p.equals(prefix))
{
namespace = attr.getNodeValue();
break;
}
}
}
}
parent = parent.getParentNode();
}
}
return namespace;
}
/**
* Return the base identifier.
*
* @return null
*/
public String getBaseIdentifier()
{
return null;
}
/**
* @see PrefixResolver#handlesNullPrefixes()
*/
public boolean handlesNullPrefixes() {
return false;
}
}