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: IfFunction.java 3521 2007-10-16 10:55:14Z tmorgner $ 028 * ------------ 029 * (C) Copyright 2006-2007, by Pentaho Corporation. 030 */ 031 package org.jfree.formula.function.logical; 032 033 import org.jfree.formula.EvaluationException; 034 import org.jfree.formula.FormulaContext; 035 import org.jfree.formula.LibFormulaErrorValue; 036 import org.jfree.formula.function.Function; 037 import org.jfree.formula.function.ParameterCallback; 038 import org.jfree.formula.lvalues.TypeValuePair; 039 import org.jfree.formula.typing.Type; 040 import org.jfree.formula.typing.coretypes.LogicalType; 041 042 /** 043 * Creation-Date: 04.11.2006, 18:28:15 044 * 045 * @author Thomas Morgner 046 */ 047 public class IfFunction implements Function 048 { 049 private static final TypeValuePair RETURN_FALSE = new TypeValuePair(LogicalType.TYPE, Boolean.FALSE); 050 051 public IfFunction() 052 { 053 } 054 055 public String getCanonicalName() 056 { 057 return "IF"; 058 } 059 060 public TypeValuePair evaluate(final FormulaContext context, 061 final ParameterCallback parameters) 062 throws EvaluationException 063 { 064 final int parameterCount = parameters.getParameterCount(); 065 if (parameterCount < 2) 066 { 067 throw new EvaluationException(LibFormulaErrorValue.ERROR_ARGUMENTS_VALUE); 068 } 069 070 final Type conditionType = parameters.getType(0); 071 final Object conditionValue = parameters.getValue(0); 072 final Boolean condition = context.getTypeRegistry().convertToLogical(conditionType, conditionValue); 073 if(condition == null) 074 { 075 throw new EvaluationException(LibFormulaErrorValue.ERROR_INVALID_ARGUMENT_VALUE); 076 } 077 if (Boolean.TRUE.equals(condition)) 078 { 079 final Object value = parameters.getValue(1); 080 final Type type = parameters.getType(1); 081 return new TypeValuePair(type, value); 082 } 083 // if condition is false and no third parameter, return false 084 if(parameterCount == 2 || parameters.getValue(2) == null) 085 { 086 return RETURN_FALSE; 087 } 088 // else return third parameter 089 final Object value = parameters.getValue(2); 090 final Type type = parameters.getType(2); 091 return new TypeValuePair(type, value); 092 } 093 }