Source for org.jfree.formula.function.text.FindFunction

   1: /**
   2:  * =========================================
   3:  * LibFormula : a free Java formula library
   4:  * =========================================
   5:  *
   6:  * Project Info:  http://reporting.pentaho.org/libformula/
   7:  *
   8:  * (C) Copyright 2006-2007, by Pentaho Corporation and Contributors.
   9:  *
  10:  * This library is free software; you can redistribute it and/or modify it under the terms
  11:  * of the GNU Lesser General Public License as published by the Free Software Foundation;
  12:  * either version 2.1 of the License, or (at your option) any later version.
  13:  *
  14:  * This library is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY;
  15:  * without even the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.
  16:  * See the GNU Lesser General Public License for more details.
  17:  *
  18:  * You should have received a copy of the GNU Lesser General Public License along with this
  19:  * library; if not, write to the Free Software Foundation, Inc., 59 Temple Place, Suite 330,
  20:  * Boston, MA 02111-1307, USA.
  21:  *
  22:  * [Java is a trademark or registered trademark of Sun Microsystems, Inc.
  23:  * in the United States and other countries.]
  24:  *
  25:  *
  26:  * ------------
  27:  * $Id: FindFunction.java 3521 2007-10-16 10:55:14Z tmorgner $
  28:  * ------------
  29:  * (C) Copyright 2006-2007, by Pentaho Corporation.
  30:  */
  31: package org.jfree.formula.function.text;
  32: 
  33: import java.math.BigDecimal;
  34: 
  35: import org.jfree.formula.EvaluationException;
  36: import org.jfree.formula.FormulaContext;
  37: import org.jfree.formula.LibFormulaErrorValue;
  38: import org.jfree.formula.function.Function;
  39: import org.jfree.formula.function.ParameterCallback;
  40: import org.jfree.formula.lvalues.TypeValuePair;
  41: import org.jfree.formula.typing.Type;
  42: import org.jfree.formula.typing.TypeRegistry;
  43: import org.jfree.formula.typing.coretypes.NumberType;
  44: 
  45: /**
  46:  * This function returns the starting position of a given text in the given text.
  47:  *
  48:  * @author Cedric Pronzato
  49:  */
  50: public class FindFunction implements Function
  51: {
  52:   public FindFunction()
  53:   {
  54:   }
  55: 
  56:   public TypeValuePair evaluate(final FormulaContext context, final ParameterCallback parameters) throws EvaluationException
  57:   {
  58:     final int parameterCount = parameters.getParameterCount();
  59:     if (parameterCount < 2 || parameterCount > 3)
  60:     {
  61:       throw new EvaluationException(LibFormulaErrorValue.ERROR_ARGUMENTS_VALUE);
  62:     }
  63:     final TypeRegistry typeRegistry = context.getTypeRegistry();
  64: 
  65:     final Type searchType = parameters.getType(0);
  66:     final Object searchValue = parameters.getValue(0);
  67:     final Type textType = parameters.getType(1);
  68:     final Object textValue = parameters.getValue(1);
  69:     Type indexType = null;
  70:     Object indexValue = null;
  71: 
  72:     if (parameterCount == 3)
  73:     {
  74:       indexType = parameters.getType(2);
  75:       indexValue = parameters.getValue(2);
  76:     }
  77: 
  78:     final String search = typeRegistry.convertToText(searchType, searchValue);
  79:     final String text = typeRegistry.convertToText(textType, textValue);
  80: 
  81:     if (search == null || text == null)
  82:     {
  83:       throw new EvaluationException(LibFormulaErrorValue.ERROR_INVALID_ARGUMENT_VALUE);
  84:     }
  85:     int indexFrom = 0;
  86: 
  87:     if (indexType != null && indexValue != null)
  88:     {
  89:       final Number n = typeRegistry.convertToNumber(indexType, indexValue);
  90:       if (n.intValue() >= 1)
  91:       {
  92:         indexFrom = n.intValue() - 1;
  93:       }
  94:       else
  95:       {
  96:         throw new EvaluationException(LibFormulaErrorValue.ERROR_INVALID_ARGUMENT_VALUE);
  97:       }
  98:     }
  99: 
 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: