/*
 * @(#)$Id: AttPoolRefState.java,v 1.2 2001/05/01 18:13:07 Bear Exp $
 *
 * Copyright 2001 Sun Microsystems, Inc. All Rights Reserved.
 * 
 * This software is the proprietary information of Sun Microsystems, Inc.  
 * Use is subject to license terms.
 * 
 */
package com.sun.msv.reader.relax.core;

import com.sun.msv.grammar.Expression;
import com.sun.msv.reader.ExpressionWithoutChildState;

/**
 * parses <ref role="..." />.
 * 
 * @author <a href="mailto:kohsuke.kawaguchi@eng.sun.com">Kohsuke KAWAGUCHI</a>
 */
public class AttPoolRefState extends ExpressionWithoutChildState
{
	protected Expression makeExpression()
	{
		final String role = startTag.getAttribute("role");
		if( role==null )
		{
			reader.reportError( reader.ERR_MISSING_ATTRIBUTE, "ref", "role" );
			return Expression.epsilon;
		}
		
		final String namespace = startTag.getAttribute("namespace");
		
		final RELAXCoreReader reader = (RELAXCoreReader)this.reader;
		
		return reader.resolveAttPoolRef(namespace,role);
	}
}