/*
* Licensed to the Apache Software Foundation (ASF) under one or more
* contributor license agreements. See the NOTICE file distributed with
* this work for additional information regarding copyright ownership.
* The ASF licenses this file to You under the Apache License, Version 2.0
* (the "License"); you may not use this file except in compliance with
* the License. You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
/*
* Created on May 15, 2005
*
*/
package org.apache.poi.hssf.record.formula.functions;
import org.apache.poi.hssf.record.formula.eval.ErrorEval;
import org.apache.poi.hssf.record.formula.eval.Eval;
import org.apache.poi.hssf.record.formula.eval.NumericValueEval;
import org.apache.poi.hssf.record.formula.eval.StringEval;
import org.apache.poi.hssf.record.formula.eval.StringValueEval;
import org.apache.poi.hssf.record.formula.eval.ValueEval;
/**
* An implementation of the REPLACE function:
* Replaces part of a text string based on the number of characters
* you specify, with another text string.
* @author Manda Wilson < wilson at c bio dot msk cc dot org >
*/
public class Replace extends TextFunction {
/**
* Replaces part of a text string based on the number of characters
* you specify, with another text string.
*
* @see org.apache.poi.hssf.record.formula.eval.Eval
*/
public Eval evaluate(Eval[] operands, int srcCellRow, short srcCellCol) {
Eval retval = null;
String oldStr = null;
String newStr = null;
int startNum = 0;
int numChars = 0;
switch (operands.length) {
default:
retval = ErrorEval.VALUE_INVALID;
case 4:
// first operand is text string containing characters to replace
// second operand is position of first character to replace
// third operand is the number of characters in the old string
// you want to replace with new string
// fourth operand is the new string
ValueEval firstveval = singleOperandEvaluate(operands[0], srcCellRow, srcCellCol);
ValueEval secondveval = singleOperandEvaluate(operands[1], srcCellRow, srcCellCol);
ValueEval thirdveval = singleOperandEvaluate(operands[2], srcCellRow, srcCellCol);
ValueEval fourthveval = singleOperandEvaluate(operands[3], srcCellRow, srcCellCol);
if (firstveval instanceof StringValueEval
&& secondveval instanceof NumericValueEval
&& thirdveval instanceof NumericValueEval
&& fourthveval instanceof StringValueEval) {
StringValueEval oldStrEval = (StringValueEval) firstveval;
oldStr = oldStrEval.getStringValue();
NumericValueEval startNumEval = (NumericValueEval) secondveval;
// NOTE: it is safe to cast to int here
// because in Excel =REPLACE("task", 2.7, 3, "est")
// returns test
// so 2.7 must be truncated to 2
// and =REPLACE("task", 1, 1.9, "") returns ask
// so 1.9 must be truncated to 1
startNum = (int) startNumEval.getNumberValue();
NumericValueEval numCharsEval = (NumericValueEval) thirdveval;
numChars = (int) numCharsEval.getNumberValue();
StringValueEval newStrEval = (StringValueEval) fourthveval;
newStr = newStrEval.getStringValue();
} else {
retval = ErrorEval.VALUE_INVALID;
}
}
if (retval == null) {
if (startNum < 1 || numChars < 0) {
retval = ErrorEval.VALUE_INVALID;
} else {
StringBuffer strBuff = new StringBuffer(oldStr);
// remove any characters that should be replaced
if (startNum <= oldStr.length() && numChars != 0) {
strBuff.delete(startNum - 1, startNum - 1 + numChars);
}
// now insert (or append) newStr
if (startNum > strBuff.length()) {
strBuff.append(newStr);
} else {
strBuff.insert(startNum - 1, newStr);
}
retval = new StringEval(strBuff.toString());
}
}
return retval;
}
}