/*
* The Apache Software License, Version 1.1
*
*
* Copyright (c) 1999-2003 The Apache Software Foundation. All rights
* reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
*
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
*
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in
* the documentation and/or other materials provided with the
* distribution.
*
* 3. The end-user documentation included with the redistribution,
* if any, must include the following acknowledgment:
* "This product includes software developed by the
* Apache Software Foundation (http://www.apache.org/)."
* Alternately, this acknowledgment may appear in the software itself,
* if and wherever such third-party acknowledgments normally appear.
*
* 4. The names "Xalan" and "Apache Software Foundation" must
* not be used to endorse or promote products derived from this
* software without prior written permission. For written
* permission, please contact apache@apache.org.
*
* 5. Products derived from this software may not be called "Apache",
* nor may "Apache" appear in their name, without prior written
* permission of the Apache Software Foundation.
*
* THIS SOFTWARE IS PROVIDED ``AS IS'' AND ANY EXPRESSED OR IMPLIED
* WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
* OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
* DISCLAIMED. IN NO EVENT SHALL THE APACHE SOFTWARE FOUNDATION OR
* ITS CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
* SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
* LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF
* USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND
* ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
* OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT
* OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
* SUCH DAMAGE.
* ====================================================================
*
* This software consists of voluntary contributions made by many
* individuals on behalf of the Apache Software Foundation and was
* originally based on software copyright (c) 1999, Lotus
* Development Corporation., http://www.lotus.com. For more
* information on the Apache Software Foundation, please see
* <http://www.apache.org/>.
*/
package org.apache.xpath.functions;
import org.apache.xalan.res.XSLMessages;
import org.apache.xml.utils.XMLString;
import org.apache.xpath.XPathContext;
import org.apache.xpath.objects.XObject;
import org.apache.xpath.objects.XString;
import org.apache.xpath.res.XPATHErrorResources;
/**
* <meta name="usage" content="advanced"/>
* Execute the Substring() function.
*/
public class FuncSubstring extends Function3Args
{
/**
* Execute the function. The function must return
* a valid object.
* @param xctxt The current execution context.
* @return A valid XObject.
*
* @throws javax.xml.transform.TransformerException
*/
public XObject execute(XPathContext xctxt) throws javax.xml.transform.TransformerException
{
XMLString s1 = m_arg0.execute(xctxt).xstr();
double start = m_arg1.execute(xctxt).num();
int lenOfS1 = s1.length();
XMLString substr;
if (lenOfS1 <= 0)
return XString.EMPTYSTRING;
else
{
int startIndex;
if (Double.isNaN(start))
{
// Double.MIN_VALUE doesn't work with math below
// so just use a big number and hope I never get caught.
start = -1000000;
startIndex = 0;
}
else
{
start = Math.round(start);
startIndex = (start > 0) ? (int) start - 1 : 0;
}
if (null != m_arg2)
{
double len = m_arg2.num(xctxt);
int end = (int) (Math.round(len) + start) - 1;
// Normalize end index.
if (end < 0)
end = 0;
else if (end > lenOfS1)
end = lenOfS1;
if (startIndex > lenOfS1)
startIndex = lenOfS1;
substr = s1.substring(startIndex, end);
}
else
{
if (startIndex > lenOfS1)
startIndex = lenOfS1;
substr = s1.substring(startIndex);
}
}
return (XString)substr; // cast semi-safe
}
/**
* Check that the number of arguments passed to this function is correct.
*
*
* @param argNum The number of arguments that is being passed to the function.
*
* @throws WrongNumberArgsException
*/
public void checkNumberArgs(int argNum) throws WrongNumberArgsException
{
if (argNum < 2)
reportWrongNumberArgs();
}
/**
* Constructs and throws a WrongNumberArgException with the appropriate
* message for this function object.
*
* @throws WrongNumberArgsException
*/
protected void reportWrongNumberArgs() throws WrongNumberArgsException {
throw new WrongNumberArgsException(XSLMessages.createXPATHMessage(XPATHErrorResources.ER_TWO_OR_THREE, null)); //"2 or 3");
}
}