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

   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: ReplaceFunction.java 2785 2007-05-08 11:12:25Z taqua $
  28:  * ------------
  29:  * (C) Copyright 2006-2007, by Pentaho Corporation.
  30:  */
  31: package org.jfree.formula.function.text;
  32: 
  33: import org.jfree.formula.EvaluationException;
  34: import org.jfree.formula.FormulaContext;
  35: import org.jfree.formula.LibFormulaErrorValue;
  36: import org.jfree.formula.function.Function;
  37: import org.jfree.formula.function.ParameterCallback;
  38: import org.jfree.formula.lvalues.TypeValuePair;
  39: import org.jfree.formula.typing.Type;
  40: import org.jfree.formula.typing.TypeRegistry;
  41: import org.jfree.formula.typing.coretypes.TextType;
  42: 
  43: /**
  44:  * This function returns text where an old text is substituted with a new text.
  45:  *
  46:  * @author Cedric Pronzato
  47:  */
  48: public class ReplaceFunction implements Function
  49: {
  50:   public ReplaceFunction()
  51:   {
  52:   }
  53: 
  54:   public TypeValuePair evaluate(final FormulaContext context,
  55:                                 final ParameterCallback parameters) throws EvaluationException
  56:   {
  57:     final int parameterCount = parameters.getParameterCount();
  58:     if (parameterCount != 4)
  59:     {
  60:       throw new EvaluationException(LibFormulaErrorValue.ERROR_ARGUMENTS_VALUE);
  61:     }
  62:     final TypeRegistry typeRegistry = context.getTypeRegistry();
  63: 
  64:     final Type newTextType = parameters.getType(3);
  65:     final Object newTextValue = parameters.getValue(3);
  66:     final Type textType = parameters.getType(0);
  67:     final Object textValue = parameters.getValue(0);
  68:     final Type startType = parameters.getType(1);
  69:     final Object startValue = parameters.getValue(1);
  70:     final Type lengthType = parameters.getType(2);
  71:     final Object lengthValue = parameters.getValue(2);
  72: 
  73:     final String newText = typeRegistry.convertToText(newTextType, newTextValue);
  74:     final String text = typeRegistry.convertToText(textType, textValue);
  75:     final Number start = typeRegistry.convertToNumber(startType, startValue);
  76:     final Number length = typeRegistry.convertToNumber(lengthType, lengthValue);
  77:     
  78:     final MidFunction function = new MidFunction();
  79:     final String result1 = function.process(text, new Integer(1), new Integer(start.intValue() - 1));
  80:     final String result2 = function.process(text,
  81:         new Integer(start.intValue() + length.intValue()), new Integer(text.length()));
  82: 
  83: 
  84:     final StringBuffer buffer = new StringBuffer();
  85:     buffer.append(result1);
  86:     buffer.append(newText);
  87:     buffer.append(result2);
  88:     return new TypeValuePair(TextType.TYPE, buffer.toString());
  89:   }
  90: 
  91:   public String getCanonicalName()
  92:   {
  93:     return "REPLACE";
  94:   }
  95: