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: ReplaceFunction.java 2785 2007-05-08 11:12:25Z 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 ReplaceFunction implements Function
049 {
050 public ReplaceFunction()
051 {
052 }
053
054 public TypeValuePair evaluate(final FormulaContext context,
055 final ParameterCallback parameters) throws EvaluationException
056 {
057 final int parameterCount = parameters.getParameterCount();
058 if (parameterCount != 4)
059 {
060 throw new EvaluationException(LibFormulaErrorValue.ERROR_ARGUMENTS_VALUE);
061 }
062 final TypeRegistry typeRegistry = context.getTypeRegistry();
063
064 final Type newTextType = parameters.getType(3);
065 final Object newTextValue = parameters.getValue(3);
066 final Type textType = parameters.getType(0);
067 final Object textValue = parameters.getValue(0);
068 final Type startType = parameters.getType(1);
069 final Object startValue = parameters.getValue(1);
070 final Type lengthType = parameters.getType(2);
071 final Object lengthValue = parameters.getValue(2);
072
073 final String newText = typeRegistry.convertToText(newTextType, newTextValue);
074 final String text = typeRegistry.convertToText(textType, textValue);
075 final Number start = typeRegistry.convertToNumber(startType, startValue);
076 final Number length = typeRegistry.convertToNumber(lengthType, lengthValue);
077
078 final MidFunction function = new MidFunction();
079 final String result1 = function.process(text, new Integer(1), new Integer(start.intValue() - 1));
080 final String result2 = function.process(text,
081 new Integer(start.intValue() + length.intValue()), new Integer(text.length()));
082
083
084 final StringBuffer buffer = new StringBuffer();
085 buffer.append(result1);
086 buffer.append(newText);
087 buffer.append(result2);
088 return new TypeValuePair(TextType.TYPE, buffer.toString());
089 }
090
091 public String getCanonicalName()
092 {
093 return "REPLACE";
094 }
095
096 }