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: YearFunction.java 2822 2007-05-20 21:47:52Z mimil $
028 * ------------
029 * (C) Copyright 2006-2007, by Pentaho Corporation.
030 */
031 package org.jfree.formula.function.datetime;
032
033 import java.util.Calendar;
034 import java.util.Date;
035
036 import org.jfree.formula.EvaluationException;
037 import org.jfree.formula.FormulaContext;
038 import org.jfree.formula.LibFormulaErrorValue;
039 import org.jfree.formula.function.Function;
040 import org.jfree.formula.function.ParameterCallback;
041 import org.jfree.formula.lvalues.TypeValuePair;
042 import org.jfree.formula.typing.TypeRegistry;
043 import org.jfree.formula.typing.coretypes.NumberType;
044 import org.jfree.formula.util.DateUtil;
045
046 /**
047 * This function extracts the year from a date.
048 *
049 * @author Cedric Pronzato
050 */
051 public class YearFunction implements Function
052 {
053 public YearFunction()
054 {
055 }
056
057 public String getCanonicalName()
058 {
059 return "YEAR";
060 }
061
062 public TypeValuePair evaluate(final FormulaContext context,
063 final ParameterCallback parameters) throws EvaluationException
064 {
065 if (parameters.getParameterCount() != 1)
066 {
067 throw new EvaluationException(LibFormulaErrorValue.ERROR_ARGUMENTS_VALUE);
068 }
069
070 final TypeRegistry typeRegistry = context.getTypeRegistry();
071
072 final Date d = typeRegistry.convertToDate(parameters.getType(0), parameters
073 .getValue(0));
074
075 if (d == null)
076 {
077 throw new EvaluationException(
078 LibFormulaErrorValue.ERROR_INVALID_ARGUMENT_VALUE);
079 }
080
081 final Calendar gc = DateUtil.createCalendar(d, context
082 .getLocalizationContext());
083
084 final int year = gc
085 .get(Calendar.YEAR);
086 return new TypeValuePair(NumberType.GENERIC_NUMBER, new Integer(year));
087 }
088 }