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: IsNaFunction.java 2887 2007-06-06 17:07:52Z taqua $
028     * ------------
029     * (C) Copyright 2006-2007, by Pentaho Corporation.
030     */
031    package org.jfree.formula.function.information;
032    
033    import org.jfree.formula.ErrorValue;
034    import org.jfree.formula.EvaluationException;
035    import org.jfree.formula.FormulaContext;
036    import org.jfree.formula.LibFormulaErrorValue;
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.Type;
041    import org.jfree.formula.typing.coretypes.ErrorType;
042    import org.jfree.formula.typing.coretypes.LogicalType;
043    import org.jfree.util.Log;
044    
045    /**
046     * This function returns true if the parameter is of error type NA.
047     *
048     * @author Cedric Pronzato
049     */
050    public class IsNaFunction implements Function
051    {
052    
053      private static final TypeValuePair RETURN_FALSE = new TypeValuePair(LogicalType.TYPE, Boolean.FALSE);
054      private static final TypeValuePair RETURN_TRUE = new TypeValuePair(LogicalType.TYPE, Boolean.TRUE);
055    
056      public IsNaFunction()
057      {
058      }
059    
060      public TypeValuePair evaluate(final FormulaContext context,
061                                    final ParameterCallback parameters) throws EvaluationException
062      {
063        if (parameters.getParameterCount() != 1)
064        {
065          throw new EvaluationException(LibFormulaErrorValue.ERROR_ARGUMENTS_VALUE);
066        }
067    
068        try
069        {
070          final Type type = parameters.getType(0);
071          final Object value = parameters.getValue(0);
072    
073          if (ErrorType.TYPE.equals(type) && value instanceof ErrorValue)
074          {
075            Log.warn ("Passing errors around is deprecated. Throw exceptions instead.");
076            final ErrorValue na = (ErrorValue) value;
077            if (na.getErrorCode() == LibFormulaErrorValue.ERROR_NA)
078            {
079              return RETURN_TRUE;
080            }
081          }
082          else
083          {
084            if (value == null)
085            {
086              return RETURN_TRUE;
087            }
088          }
089        }
090        catch (EvaluationException e)
091        {
092          if (e.getErrorValue().getErrorCode() == LibFormulaErrorValue.ERROR_NA)
093          {
094            return RETURN_TRUE;
095          }
096        }
097    
098        return RETURN_FALSE;
099      }
100    
101      public String getCanonicalName()
102      {
103        return "ISNA";
104      }
105    
106    }