Frames | No Frames |
1: /** 2: * ========================================= 3: * LibFormula : a free Java formula library 4: * ========================================= 5: * 6: * Project Info: http://reporting.pentaho.org/libformula/ 7: * 8: * (C) Copyright 2006-2007, by Pentaho Corporation and Contributors. 9: * 10: * This library is free software; you can redistribute it and/or modify it under the terms 11: * of the GNU Lesser General Public License as published by the Free Software Foundation; 12: * either version 2.1 of the License, or (at your option) any later version. 13: * 14: * This library is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY; 15: * without even the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. 16: * See the GNU Lesser General Public License for more details. 17: * 18: * You should have received a copy of the GNU Lesser General Public License along with this 19: * library; if not, write to the Free Software Foundation, Inc., 59 Temple Place, Suite 330, 20: * Boston, MA 02111-1307, USA. 21: * 22: * [Java is a trademark or registered trademark of Sun Microsystems, Inc. 23: * in the United States and other countries.] 24: * 25: * 26: * ------------ 27: * $Id: TFunction.java,v 1.5 2007/04/01 13:51:53 taqua Exp $ 28: * ------------ 29: * (C) Copyright 2006-2007, by Pentaho Corporation. 30: */ 31: package org.jfree.formula.function.text; 32: 33: import org.jfree.formula.EvaluationException; 34: import org.jfree.formula.FormulaContext; 35: import org.jfree.formula.LibFormulaErrorValue; 36: import org.jfree.formula.function.Function; 37: import org.jfree.formula.function.ParameterCallback; 38: import org.jfree.formula.lvalues.TypeValuePair; 39: import org.jfree.formula.typing.Type; 40: import org.jfree.formula.typing.coretypes.TextType; 41: 42: /** 43: * This function returns the given text value or a zero lenght string for non text type. 44: * 45: * @author Cedric Pronzato 46: * 47: */ 48: public class TFunction implements Function 49: { 50: private static final TypeValuePair EMPTY_STRING = new TypeValuePair(TextType.TYPE, ""); 51: 52: public TFunction() 53: { 54: } 55: 56: public TypeValuePair evaluate(FormulaContext context, ParameterCallback parameters) throws EvaluationException 57: { 58: final int parameterCount = parameters.getParameterCount(); 59: if (parameterCount < 1) 60: { 61: throw new EvaluationException(LibFormulaErrorValue.ERROR_ARGUMENTS_VALUE); 62: } 63: final Type type1 = parameters.getType(0); 64: final Object value1 = parameters.getValue(0); 65: 66: if(type1 instanceof TextType || value1 instanceof String) 67: { 68: return new TypeValuePair(TextType.TYPE, value1); 69: } 70: else 71: { 72: return EMPTY_STRING; 73: } 74: } 75: 76: public String getCanonicalName() 77: { 78: return "T"; 79: } 80: 81: }