/*
* 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) 2006 - 2013 Pentaho Corporation and Contributors. All rights reserved.
*/
package org.pentaho.reporting.libraries.formula.function.information;
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.coretypes.LogicalType;
/**
* Document me!
*
* @author : Thomas Morgner
*/
public class IsBlankFunction implements Function
{
private static final TypeValuePair RETURN_FALSE = new TypeValuePair(
LogicalType.TYPE, Boolean.FALSE);
private static final TypeValuePair RETURN_TRUE = new TypeValuePair(
LogicalType.TYPE, Boolean.TRUE);
private static final long serialVersionUID = 3352413434463488403L;
public IsBlankFunction()
{
}
public String getCanonicalName()
{
return "ISBLANK";
}
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);
}
try
{
final Object value = parameters.getValue(0);
final LValue raw = parameters.getRaw(0);
if (raw instanceof ContextLookup)
{
if (value == null)
{
return RETURN_TRUE;
}
}
}
catch (EvaluationException e)
{
if (e.getErrorValue().getErrorCode() == LibFormulaErrorValue.ERROR_NA)
{
return RETURN_TRUE;
}
return RETURN_FALSE;
}
return RETURN_FALSE;
}
}