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: FindFunction.java 3521 2007-10-16 10:55:14Z tmorgner $
028     * ------------
029     * (C) Copyright 2006-2007, by Pentaho Corporation.
030     */
031    package org.jfree.formula.function.text;
032    
033    import java.math.BigDecimal;
034    
035    import org.jfree.formula.EvaluationException;
036    import org.jfree.formula.FormulaContext;
037    import org.jfree.formula.LibFormulaErrorValue;
038    import org.jfree.formula.function.Function;
039    import org.jfree.formula.function.ParameterCallback;
040    import org.jfree.formula.lvalues.TypeValuePair;
041    import org.jfree.formula.typing.Type;
042    import org.jfree.formula.typing.TypeRegistry;
043    import org.jfree.formula.typing.coretypes.NumberType;
044    
045    /**
046     * This function returns the starting position of a given text in the given text.
047     *
048     * @author Cedric Pronzato
049     */
050    public class FindFunction implements Function
051    {
052      public FindFunction()
053      {
054      }
055    
056      public TypeValuePair evaluate(final FormulaContext context, final ParameterCallback parameters) throws EvaluationException
057      {
058        final int parameterCount = parameters.getParameterCount();
059        if (parameterCount < 2 || parameterCount > 3)
060        {
061          throw new EvaluationException(LibFormulaErrorValue.ERROR_ARGUMENTS_VALUE);
062        }
063        final TypeRegistry typeRegistry = context.getTypeRegistry();
064    
065        final Type searchType = parameters.getType(0);
066        final Object searchValue = parameters.getValue(0);
067        final Type textType = parameters.getType(1);
068        final Object textValue = parameters.getValue(1);
069        Type indexType = null;
070        Object indexValue = null;
071    
072        if (parameterCount == 3)
073        {
074          indexType = parameters.getType(2);
075          indexValue = parameters.getValue(2);
076        }
077    
078        final String search = typeRegistry.convertToText(searchType, searchValue);
079        final String text = typeRegistry.convertToText(textType, textValue);
080    
081        if (search == null || text == null)
082        {
083          throw new EvaluationException(LibFormulaErrorValue.ERROR_INVALID_ARGUMENT_VALUE);
084        }
085        int indexFrom = 0;
086    
087        if (indexType != null && indexValue != null)
088        {
089          final Number n = typeRegistry.convertToNumber(indexType, indexValue);
090          if (n.intValue() >= 1)
091          {
092            indexFrom = n.intValue() - 1;
093          }
094          else
095          {
096            throw new EvaluationException(LibFormulaErrorValue.ERROR_INVALID_ARGUMENT_VALUE);
097          }
098        }
099    
100        final int index = text.indexOf(search, indexFrom);
101        if (index < 0)
102        {
103          throw new EvaluationException(LibFormulaErrorValue.ERROR_NOT_FOUND_VALUE);
104        }
105    
106        return new TypeValuePair(NumberType.GENERIC_NUMBER, new BigDecimal(index + 1));
107      }
108    
109      public String getCanonicalName()
110      {
111        return "FIND";
112      }
113    
114    }