/*

 * reserved comment block

 * DO NOT REMOVE OR ALTER!

 */

/*

 * Licensed to the Apache Software Foundation (ASF) under one or more

 * contributor license agreements.  See the NOTICE file distributed with

 * this work for additional information regarding copyright ownership.

 * The ASF licenses this file to You 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.

 */

package com.sun.org.apache.xpath.internal.jaxp;

import javax.xml.transform.TransformerException;

import javax.xml.xpath.XPathVariableResolver;

import com.sun.org.apache.xml.internal.utils.QName;

import com.sun.org.apache.xpath.internal.VariableStack;

import com.sun.org.apache.xpath.internal.XPathContext;

import com.sun.org.apache.xpath.internal.objects.XObject;

import com.sun.org.apache.xpath.internal.res.XPATHErrorResources;

import com.sun.org.apache.xalan.internal.res.XSLMessages;

/**

 * Overrides {@link VariableStack} and delegates the call to

 * {@link javax.xml.xpath.XPathVariableResolver}.

 *

 * @author Ramesh Mandava

 */

public class JAXPVariableStack extends VariableStack {

    private final XPathVariableResolver resolver;

    public JAXPVariableStack(XPathVariableResolver resolver) {

        this.resolver = resolver;

    }

    public XObject getVariableOrParam(XPathContext xctxt, QName qname)

        throws TransformerException,IllegalArgumentException {

        if ( qname == null ) {

            //JAXP 1.3 spec says that if variable name is null then

            // we need to through IllegalArgumentException

            String fmsg = XSLMessages.createXPATHMessage(

                XPATHErrorResources.ER_ARG_CANNOT_BE_NULL,

                new Object[] {"Variable qname"} );

            throw new IllegalArgumentException( fmsg );

        }

        javax.xml.namespace.QName name =

            new javax.xml.namespace.QName(

                qname.getNamespace(),

                qname.getLocalPart());

        Object varValue = resolver.resolveVariable( name );

        if ( varValue == null ) {

            String fmsg = XSLMessages.createXPATHMessage(

                XPATHErrorResources.ER_RESOLVE_VARIABLE_RETURNS_NULL,

                new Object[] { name.toString()} );

            throw new TransformerException( fmsg );

        }

        return XObject.create( varValue, xctxt );

    }

}