/*
* @(#)$Id: RefState.java 1566 2003-06-09 20:37:49Z kk122374 $
*
* 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.ReferenceExp;
import com.sun.msv.grammar.trex.TREXGrammar;
import com.sun.msv.reader.ExpressionWithoutChildState;
/**
* parses <ref> pattern.
*
* @author <a href="mailto:kohsuke.kawaguchi@eng.sun.com">Kohsuke KAWAGUCHI</a>
*/
public class RefState extends ExpressionWithoutChildState {
public RefState( boolean parentRef ) {
this.parentRef = parentRef;
}
protected boolean parentRef;
protected Expression makeExpression() {
final String name = startTag.getCollapsedAttribute("name");
if(name==null) {
// name attribute is required.
reader.reportError( TREXBaseReader.ERR_MISSING_ATTRIBUTE,
"ref","name");
// recover by returning something that can be interpreted as Pattern
return Expression.nullSet;
}
TREXGrammar grammar = ((TREXBaseReader)this.reader).grammar;
if( parentRef ) {
grammar = grammar.getParentGrammar();
if( grammar==null ) {
reader.reportError( TREXBaseReader.ERR_NONEXISTENT_PARENT_GRAMMAR );
return Expression.nullSet;
// recover by returning something that can be interpreted as Pattern
}
}
ReferenceExp r = grammar.namedPatterns.getOrCreate(name);
wrapUp(r);
return r;
}
/**
* Performs the final wrap-up.
*/
protected void wrapUp( ReferenceExp r ) {
reader.backwardReference.memorizeLink(r);
}
}