001    /**
002     * =========================================
003     * LibFormula : a free Java formula library
004     * =========================================
005     *
006     * Project Info:  http://reporting.pentaho.org/libformula/
007     *
008     * (C) Copyright 2006-2007, by Pentaho Corporation and Contributors.
009     *
010     * This library is free software; you can redistribute it and/or modify it under the terms
011     * of the GNU Lesser General Public License as published by the Free Software Foundation;
012     * either version 2.1 of the License, or (at your option) any later version.
013     *
014     * This library is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY;
015     * without even the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.
016     * See the GNU Lesser General Public License for more details.
017     *
018     * You should have received a copy of the GNU Lesser General Public License along with this
019     * library; if not, write to the Free Software Foundation, Inc., 59 Temple Place, Suite 330,
020     * Boston, MA 02111-1307, USA.
021     *
022     * [Java is a trademark or registered trademark of Sun Microsystems, Inc.
023     * in the United States and other countries.]
024     *
025     *
026     * ------------
027     * $Id: DateFunction.java 2847 2007-05-21 18:57:59Z mimil $
028     * ------------
029     * (C) Copyright 2006-2007, by Pentaho Corporation.
030     */
031    package org.jfree.formula.function.datetime;
032    
033    import org.jfree.formula.EvaluationException;
034    import org.jfree.formula.FormulaContext;
035    import org.jfree.formula.LibFormulaErrorValue;
036    import org.jfree.formula.LocalizationContext;
037    import org.jfree.formula.function.Function;
038    import org.jfree.formula.function.ParameterCallback;
039    import org.jfree.formula.lvalues.TypeValuePair;
040    import org.jfree.formula.typing.TypeRegistry;
041    import org.jfree.formula.typing.coretypes.DateTimeType;
042    import org.jfree.formula.util.DateUtil;
043    
044    /**
045     * Creation-Date: 04.11.2006, 18:59:11
046     * 
047     * @author Thomas Morgner
048     */
049    public class DateFunction implements Function
050    {
051      public DateFunction()
052      {
053      }
054    
055      public String getCanonicalName()
056      {
057        return "DATE";
058      }
059    
060      public TypeValuePair evaluate(final FormulaContext context,
061          final ParameterCallback parameters) throws EvaluationException
062      {
063        if (parameters.getParameterCount() != 3)
064        {
065          throw new EvaluationException(LibFormulaErrorValue.ERROR_ARGUMENTS_VALUE);
066        }
067    
068        final TypeRegistry typeRegistry = context.getTypeRegistry();
069    
070        final Number n1 = typeRegistry.convertToNumber(parameters.getType(0),
071            parameters.getValue(0));
072        final Number n2 = typeRegistry.convertToNumber(parameters.getType(1),
073            parameters.getValue(1));
074        final Number n3 = typeRegistry.convertToNumber(parameters.getType(2),
075            parameters.getValue(2));
076    
077        if (n1 == null || n2 == null || n3 == null)
078        {
079          throw new EvaluationException(
080              LibFormulaErrorValue.ERROR_INVALID_ARGUMENT_VALUE);
081        }
082    
083        final LocalizationContext localizationContext = context
084            .getLocalizationContext();
085        final java.sql.Date date = DateUtil.createDate(n1.intValue(),
086            n2.intValue(), n3.intValue(), localizationContext);
087    
088        return new TypeValuePair(DateTimeType.DATE_TYPE, date);
089      }
090    }