/*
 * @(#)$Id: ValueState.java,v 1.7 2002/10/06 18:07:05 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.ng;

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

import org.relaxng.datatype.Datatype;
import org.relaxng.datatype.DatatypeException;

/**
 * parses <value> pattern.
 * 
 * @author <a href="mailto:kohsuke.kawaguchi@eng.sun.com">Kohsuke KAWAGUCHI</a>
 */
public class ValueState extends ExpressionWithoutChildState {
	
	protected final StringBuffer text = new StringBuffer();
	
	public void characters( char[] buf, int from, int len ) {
		text.append(buf,from,len);
	}
	public void ignorableWhitespace( char[] buf, int from, int len ) {
		text.append(buf,from,len);
	}
	
	protected Expression makeExpression() {
		final RELAXNGReader reader = (RELAXNGReader)this.reader;
		String typeName = startTag.getCollapsedAttribute("type");
		
		Datatype type;
		
		StringPair typeFullName;
		
		if(typeName==null) {
            try {
    			// defaults to built-in token type.
    			type = reader.resolveDataTypeLibrary("").createDatatype("token");
    			typeFullName = new StringPair("","token");
            } catch( DatatypeException e ) {
                // since token is the built-in datatype,
                // this can't happen
                e.printStackTrace();
                throw new InternalError();
            }
		} else {
			type = reader.resolveDataType(typeName);
			typeFullName = new StringPair(reader.datatypeLibURI,typeName);
		}
		
		Object value = type.createValue(text.toString(),reader);
		if( value==null ) {
			// this is not a good value for this type.
			reader.reportError( reader.ERR_BAD_DATA_VALUE, typeName, text.toString().trim() );
			return Expression.nullSet;	// recover by returning something.
		}
		
		return reader.pool.createValue( type, typeFullName, value );
	}
}