/*
 * @(#)$Id: AttPoolState.java,v 1.3 2001/05/16 19:31:27 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 org.xml.sax.Locator;
import com.sun.msv.grammar.Expression;
import com.sun.msv.grammar.ReferenceExp;
import com.sun.msv.grammar.relax.AttPoolClause;

/**
 * parses <attPool> element.
 * 
 * @author <a href="mailto:kohsuke.kawaguchi@eng.sun.com">Kohsuke KAWAGUCHI</a>
 */
public class AttPoolState extends ClauseState {
	
	protected void endSelf( ) {
	
		super.endSelf();
		
		final String role = startTag.getAttribute("role");
		if(role==null) {
			reader.reportError(reader.ERR_MISSING_ATTRIBUTE, "attPool","role");
			return;	// recover by ignoring this declaration
		}
		
		if( startTag.getAttribute("combine")==null ) {
			AttPoolClause c = getReader().module.attPools.getOrCreate(role);
		
			if(c.exp!=null) {
				// someone has already initialized this clause.
				// this happens when more than one attPool element declares the same role.
				reader.reportError(
					new Locator[]{getReader().getDeclaredLocationOf(c),location},
					RELAXCoreReader.ERR_MULTIPLE_ATTPOOL_DECLARATIONS, new Object[]{role} );
				// recover from error by ignoring previous tag declaration
			}
		
			c.exp = exp;	// exp holds a sequence of AttributeExp
			getReader().setDeclaredLocationOf(c);	// remember where this AttPool is declared
		} else {
			// this attPool has @combine
			
			ReferenceExp e = getReader().combinedAttPools._getOrCreate(role);
			if( e.exp==null )	e.exp = exp.epsilon;
			// append newly found attributes.
			e.exp = reader.pool.createSequence( exp, e.exp );
			reader.setDeclaredLocationOf(e);
		}
		
		
		return;
	}
}