/*
 * @(#)$Id: AttributeState.java,v 1.7 2001/11/28 01:49:59 kk122374 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.trex;

import com.sun.msv.grammar.Expression;
import com.sun.msv.grammar.AttributeExp;

/**
 * parses <attribute> pattern.
 * 
 * @author <a href="mailto:kohsuke.kawaguchi@eng.sun.com">Kohsuke KAWAGUCHI</a>
 */
public class AttributeState extends NameClassAndExpressionState
{
	protected boolean firstChild=true;
	
	protected Expression initialExpression() {
		// <attribute> defaults to <anyString />
		return Expression.anyString;
	}

	protected String getNamespace() {
		final String ns = startTag.getAttribute("ns");
		final boolean global = "true".equals(startTag.getAttribute("global"));
		
		if( ns!=null )	return ns;	// "ns" attribute always has precedence.
		
		// if global="true" is specified, it defaults to propagated ns attribute.
		if( global )	return ((TREXBaseReader)reader).targetNamespace;
		
		// otherwise, it defaults to ""
		return "";
	}
			

	protected Expression castExpression( Expression initialExpression, Expression newChild ) {
		// <attribute> is allowed to have only one pattern
		if(!firstChild)
			reader.reportError( TREXBaseReader.ERR_MORE_THAN_ONE_CHILD_EXPRESSION );
			// recover by ignore the error
		firstChild = false;
		return newChild;
	}

	protected Expression annealExpression( Expression contentModel ) {
		Expression e = reader.pool.createAttribute( nameClass, contentModel );
        if(e instanceof AttributeExp)
			reader.setDeclaredLocationOf(e);
		return e;
	}
}