/*
* This program is free software; you can redistribute it and/or modify it under the
* terms of the GNU Lesser General Public License, version 2.1 as published by the Free Software
* Foundation.
*
* You should have received a copy of the GNU Lesser General Public License along with this
* program; if not, you can obtain a copy at http://www.gnu.org/licenses/old-licenses/lgpl-2.1.html
* or from the Free Software Foundation, Inc.,
* 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
*
* This program 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.
*
* Copyright (c) 2006 - 2013 Pentaho Corporation and Contributors. All rights reserved.
*/
package org.pentaho.reporting.libraries.formula.function.text;
import org.pentaho.reporting.libraries.formula.EvaluationException;
import org.pentaho.reporting.libraries.formula.FormulaContext;
import org.pentaho.reporting.libraries.formula.LibFormulaErrorValue;
import org.pentaho.reporting.libraries.formula.function.Function;
import org.pentaho.reporting.libraries.formula.function.ParameterCallback;
import org.pentaho.reporting.libraries.formula.lvalues.TypeValuePair;
import org.pentaho.reporting.libraries.formula.typing.Type;
import org.pentaho.reporting.libraries.formula.typing.coretypes.TextType;
/**
* This function returns the given text free of leading spaces.
* Removes all leading and trailing spaces and all extra spaces inside the text.
*
* @author Cedric Pronzato
* @see http://mercury.ccil.org/%7Ecowan/OF/textfuncs.html
*/
public class TrimFunction implements Function
{
private static final long serialVersionUID = 7379670108270974597L;
public TrimFunction()
{
}
public TypeValuePair evaluate(final FormulaContext context, final ParameterCallback parameters) throws EvaluationException
{
final int parameterCount = parameters.getParameterCount();
if (parameterCount < 1)
{
throw EvaluationException.getInstance(LibFormulaErrorValue.ERROR_ARGUMENTS_VALUE);
}
final Type type1 = parameters.getType(0);
final Object value1 = parameters.getValue(0);
final String result = context.getTypeRegistry().convertToText(type1, value1);
if(result == null)
{
throw EvaluationException.getInstance(LibFormulaErrorValue.ERROR_INVALID_ARGUMENT_VALUE);
}
// remove all unnecessary spaces ..
// we dont use regexps, because they are JDK 1.4, but this library is aimed
// for JDK 1.2.2
final char[] chars = result.toCharArray();
final StringBuffer b = new StringBuffer(chars.length);
boolean removeNextWs = true;
for (int i = 0; i < chars.length; i++)
{
final char c = chars[i];
if (Character.isWhitespace(c))
{
if (removeNextWs)
{
continue;
}
b.append(c);
removeNextWs = true;
continue;
}
b.append(c);
removeNextWs = false;
}
// now check whether the last char is a whitespace and remove that one
// if neccessary
final String trimmedResult;
if (removeNextWs && b.length() > 0)
{
trimmedResult = b.substring(0, b.length() - 1);
}
else
{
trimmedResult = b.toString();
}
return new TypeValuePair(TextType.TYPE, trimmedResult);
}
public String getCanonicalName()
{
return "TRIM";
}
}