/*
* $Header: /home/projects/jaxen/scm/jaxen/src/java/main/org/jaxen/function/NormalizeSpaceFunction.java,v 1.17 2006/02/05 21:47:41 elharo Exp $
* $Revision: 1.17 $
* $Date: 2006/02/05 21:47:41 $
*
* ====================================================================
*
* Copyright 2000-2002 bob mcwhirter & James Strachan.
* All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions are
* met:
*
* * Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
*
* * 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.
*
* * Neither the name of the Jaxen Project nor the names of its
* contributors may be used to endorse or promote products derived
* from this software without specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS
* IS" AND ANY EXPRESS 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 COPYRIGHT OWNER
* OR 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 Jaxen Project and was originally
* created by bob mcwhirter <bob@werken.com> and
* James Strachan <jstrachan@apache.org>. For more information on the
* Jaxen Project, please see <http://www.jaxen.org/>.
*
* $Id: NormalizeSpaceFunction.java,v 1.17 2006/02/05 21:47:41 elharo Exp $
*/
package org.orbeon.jaxen.function;
import org.orbeon.jaxen.Context;
import org.orbeon.jaxen.Function;
import org.orbeon.jaxen.FunctionCallException;
import org.orbeon.jaxen.Navigator;
import java.util.List;
/**
* <p>
* <b>4.2</b> <code><i>string</i> normalize-space(<i>string</i>)</code>
* </p>
*
* <blockquote src="http://www.w3.org/TR/xpath#function-normalize-space">
* The <b>normalize-space</b> function
* returns the argument string with whitespace normalized by stripping
* leading and trailing whitespace and replacing sequences of whitespace
* characters by a single space. Whitespace characters are the same as
* those allowed by the <a href="http://www.w3.org/TR/REC-xml#NT-S" target="_top">S</a>
* production in XML. If the argument is omitted, it defaults to the
* context node converted to a string, in other words the <a
* href="http://www.w3.org/TR/xpath#dt-string-value"
* target="_top">string-value</a> of the context node.
* </blockquote>
*
* @author James Strachan (james@metastuff.com)
* @see <a href="http://www.w3.org/TR/xpath#function-normalize-space"
* target="_top">Section 4.2 of the XPath Specification</a>
*/
public class NormalizeSpaceFunction implements Function
{
/**
* Create a new <code>NormalizeSpaceFunction</code> object.
*/
public NormalizeSpaceFunction() {}
/**
* Returns the string-value of the first item in <code>args</code>
* after removing all leading and trailing white space, and
* replacing each other sequence of whitespace by a single space.
* Whitespace consists of the characters space (0x32), carriage return (0x0D),
* linefeed (0x0A), and tab (0x09).
*
* @param context the context at the point in the
* expression when the function is called
* @param args a list that contains exactly one item
*
* @return a normalized <code>String</code>
*
* @throws FunctionCallException if <code>args</code> does not have length one
*/
public Object call(Context context,
List args) throws FunctionCallException
{
if (args.size() == 0) {
return evaluate( context.getNodeSet(),
context.getNavigator() );
}
else if (args.size() == 1)
{
return evaluate( args.get(0),
context.getNavigator() );
}
throw new FunctionCallException( "normalize-space() cannot have more than one argument" );
}
/**
* Returns the string-value of <code>strArg</code> after removing
* all leading and trailing white space, and
* replacing each other sequence of whitespace by a single space.
* Whitespace consists of the characters space (0x32), carriage return (0x0D),
* linefeed (0x0A), and tab (0x09).
*
* @param strArg the object whose string-value is normalized
* @param nav the context at the point in the
* expression when the function is called
*
* @return the normalized string-value
*/
public static String evaluate(Object strArg,
Navigator nav)
{
String str = StringFunction.evaluate( strArg,
nav );
char[] buffer = str.toCharArray();
int write = 0;
int lastWrite = 0;
boolean wroteOne = false;
int read = 0;
while (read < buffer.length)
{
if (isXMLSpace(buffer[read]))
{
if (wroteOne)
{
buffer[write++] = ' ';
}
do
{
read++;
}
while(read < buffer.length && isXMLSpace(buffer[read]));
}
else
{
buffer[write++] = buffer[read++];
wroteOne = true;
lastWrite = write;
}
}
return new String(buffer, 0, lastWrite);
}
private static boolean isXMLSpace(char c) {
return c == ' ' || c == '\n' || c == '\r' || c == '\t';
}
}