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: SubstituteFunction.java 2752 2007-04-10 14:10:41Z taqua $ 028 * ------------ 029 * (C) Copyright 2006-2007, by Pentaho Corporation. 030 */ 031 package org.jfree.formula.function.text; 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.TypeRegistry; 041 import org.jfree.formula.typing.coretypes.TextType; 042 043 /** 044 * This function returns text where an old text is substituted with a new text. 045 * 046 * @author Cedric Pronzato 047 */ 048 public class SubstituteFunction implements Function 049 { 050 public SubstituteFunction() 051 { 052 } 053 054 public TypeValuePair evaluate(final FormulaContext context, 055 final ParameterCallback parameters) 056 throws EvaluationException 057 { 058 final int parameterCount = parameters.getParameterCount(); 059 if (parameterCount < 3 || parameterCount > 4) 060 { 061 throw new EvaluationException(LibFormulaErrorValue.ERROR_ARGUMENTS_VALUE); 062 } 063 final TypeRegistry typeRegistry = context.getTypeRegistry(); 064 065 final Type newTextType = parameters.getType(2); 066 final Object newTextValue = parameters.getValue(2); 067 final Type textType = parameters.getType(0); 068 final Object textValue = parameters.getValue(0); 069 final Type oldTextType = parameters.getType(1); 070 final Object oldTextValue = parameters.getValue(1); 071 072 final String newText = typeRegistry.convertToText(newTextType, newTextValue); 073 final String text = typeRegistry.convertToText(textType, textValue); 074 final String oldText = typeRegistry.convertToText(oldTextType, oldTextValue); 075 076 if (parameterCount == 3) 077 { 078 int index = text.indexOf(oldText); 079 if (index == -1) 080 { 081 return new TypeValuePair(TextType.TYPE, text); 082 } 083 084 String result = text; 085 while (index >= 0) 086 { 087 final StringBuffer buffer = new StringBuffer(result); 088 buffer.replace(index, index + oldText.length(), newText); 089 result = buffer.toString(); 090 index = result.indexOf(oldText, index + newText.length()); 091 } 092 return new TypeValuePair(TextType.TYPE, result); 093 } 094 095 // Instead of replacing all occurences, the user only requested to replace 096 // a specific one. 097 final Type whichType = parameters.getType(3); 098 final Object whichValue = parameters.getValue(3); 099 final Number n = typeRegistry.convertToNumber(whichType, whichValue); 100 if (n.doubleValue() < 1) 101 { 102 throw new EvaluationException( 103 LibFormulaErrorValue.ERROR_INVALID_ARGUMENT_VALUE); 104 } 105 106 final int nthOccurence = n.intValue(); 107 108 int index = text.indexOf(oldText); 109 if (index == -1) 110 { 111 return new TypeValuePair(TextType.TYPE, text); 112 } 113 114 String result = text; 115 int counter = 1; 116 while (index >= 0) 117 { 118 if (counter == nthOccurence) 119 { 120 final StringBuffer buffer = new StringBuffer(result); 121 buffer.replace(index, index + oldText.length(), newText); 122 result = buffer.toString(); 123 index = result.indexOf(oldText, index + newText.length()); 124 } 125 else 126 { 127 index = result.indexOf(oldText, index + 1); 128 } 129 counter += 1; 130 } 131 return new TypeValuePair(TextType.TYPE, result); 132 } 133 134 public String getCanonicalName() 135 { 136 return "SUBSTITUTE"; 137 } 138 139 }