/*!
* This program is free software; you can redistribute it and/or modify it under the
* terms of the GNU Lesser General Public License, version 2.1 as published by the Free Software
* Foundation.
*
* You should have received a copy of the GNU Lesser General Public License along with this
* program; if not, you can obtain a copy at http://www.gnu.org/licenses/old-licenses/lgpl-2.1.html
* or from the Free Software Foundation, Inc.,
* 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
*
* This program is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY;
* without even the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.
* See the GNU Lesser General Public License for more details.
*
* Copyright (c) 2002-2013 Pentaho Corporation.. All rights reserved.
*/
package org.pentaho.reporting.libraries.formula.function.information;
import java.math.BigDecimal;
import org.pentaho.reporting.libraries.formula.EvaluationException;
import org.pentaho.reporting.libraries.formula.FormulaContext;
import org.pentaho.reporting.libraries.formula.LibFormulaErrorValue;
import org.pentaho.reporting.libraries.formula.function.Function;
import org.pentaho.reporting.libraries.formula.function.ParameterCallback;
import org.pentaho.reporting.libraries.formula.lvalues.ContextLookup;
import org.pentaho.reporting.libraries.formula.lvalues.LValue;
import org.pentaho.reporting.libraries.formula.lvalues.TypeValuePair;
import org.pentaho.reporting.libraries.formula.typing.Sequence;
import org.pentaho.reporting.libraries.formula.typing.Type;
import org.pentaho.reporting.libraries.formula.typing.coretypes.NumberType;
/**
* This function counts the number of blank cells in the Reference provided. A cell is blank if it cell is empty.
*
* @author Cedric Pronzato
*/
// todo: maybe use something else than sequence (use array instead because sequence allows the use of scalar)
public class CountBlankFunction implements Function
{
public CountBlankFunction()
{
}
public String getCanonicalName()
{
return "COUNTBLANK";
}
public TypeValuePair evaluate(final FormulaContext context,
final ParameterCallback parameters) throws EvaluationException
{
final int parameterCount = parameters.getParameterCount();
if (parameterCount != 1)
{
throw EvaluationException.getInstance(LibFormulaErrorValue.ERROR_ARGUMENTS_VALUE);
}
int count = 0;
final Object value = parameters.getValue(0);
final Type type = parameters.getType(0);
final LValue raw = parameters.getRaw(0);
if (raw instanceof ContextLookup)
{
if (value != null)
{
try
{
final Sequence sequence = context.getTypeRegistry().convertToSequence(type, value);
while (sequence.hasNext())
{
final Object o = sequence.next();
if (o == null)
{
count++;
}
}
}
catch (EvaluationException e)
{
}
}
}
return new TypeValuePair(NumberType.GENERIC_NUMBER, new BigDecimal(count));
}
}