/**
* =========================================
* LibFormula : a free Java formula library
* =========================================
*
* Project Info: http://reporting.pentaho.org/libformula/
*
* (C) Copyright 2006-2007, by Pentaho Corporation and Contributors.
*
* This library is free software; you can redistribute it and/or modify it under the terms
* of the GNU Lesser General Public License as published by the Free Software Foundation;
* either version 2.1 of the License, or (at your option) any later version.
*
* This library 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.
*
* You should have received a copy of the GNU Lesser General Public License along with this
* library; if not, write to the Free Software Foundation, Inc., 59 Temple Place, Suite 330,
* Boston, MA 02111-1307, USA.
*
* [Java is a trademark or registered trademark of Sun Microsystems, Inc.
* in the United States and other countries.]
*
*
* ------------
* $Id: SubstituteFunction.java,v 1.5 2007/04/10 14:10:41 taqua Exp $
* ------------
* (C) Copyright 2006-2007, by Pentaho Corporation.
*/
package org.jfree.formula.function.text;
import org.jfree.formula.EvaluationException;
import org.jfree.formula.FormulaContext;
import org.jfree.formula.LibFormulaErrorValue;
import org.jfree.formula.function.Function;
import org.jfree.formula.function.ParameterCallback;
import org.jfree.formula.lvalues.TypeValuePair;
import org.jfree.formula.typing.Type;
import org.jfree.formula.typing.TypeRegistry;
import org.jfree.formula.typing.coretypes.TextType;
/**
* This function returns text where an old text is substituted with a new text.
*
* @author Cedric Pronzato
*/
public class SubstituteFunction implements Function
{
public SubstituteFunction()
{
}
public TypeValuePair evaluate(final FormulaContext context,
final ParameterCallback parameters)
throws EvaluationException
{
final int parameterCount = parameters.getParameterCount();
if (parameterCount < 3 || parameterCount > 4)
{
throw new EvaluationException(LibFormulaErrorValue.ERROR_ARGUMENTS_VALUE);
}
final TypeRegistry typeRegistry = context.getTypeRegistry();
final Type newTextType = parameters.getType(2);
final Object newTextValue = parameters.getValue(2);
final Type textType = parameters.getType(0);
final Object textValue = parameters.getValue(0);
final Type oldTextType = parameters.getType(1);
final Object oldTextValue = parameters.getValue(1);
final String newText = typeRegistry.convertToText(newTextType, newTextValue);
final String text = typeRegistry.convertToText(textType, textValue);
final String oldText = typeRegistry.convertToText(oldTextType, oldTextValue);
if (parameterCount == 3)
{
int index = text.indexOf(oldText);
if (index == -1)
{
return new TypeValuePair(TextType.TYPE, text);
}
String result = text;
while (index >= 0)
{
final StringBuffer buffer = new StringBuffer(result);
buffer.replace(index, index + oldText.length(), newText);
result = buffer.toString();
index = result.indexOf(oldText, index + newText.length());
}
return new TypeValuePair(TextType.TYPE, result);
}
// Instead of replacing all occurences, the user only requested to replace
// a specific one.
final Type whichType = parameters.getType(3);
final Object whichValue = parameters.getValue(3);
final Number n = typeRegistry.convertToNumber(whichType, whichValue);
if (n.doubleValue() < 1)
{
throw new EvaluationException(
LibFormulaErrorValue.ERROR_INVALID_ARGUMENT_VALUE);
}
final int nthOccurence = n.intValue();
int index = text.indexOf(oldText);
if (index == -1)
{
return new TypeValuePair(TextType.TYPE, text);
}
String result = text;
int counter = 1;
while (index >= 0)
{
if (counter == nthOccurence)
{
final StringBuffer buffer = new StringBuffer(result);
buffer.replace(index, index + oldText.length(), newText);
result = buffer.toString();
index = result.indexOf(oldText, index + newText.length());
}
else
{
index = result.indexOf(oldText, index + 1);
}
counter += 1;
}
return new TypeValuePair(TextType.TYPE, result);
}
public String getCanonicalName()
{
return "SUBSTITUTE";
}
}