/*
* This file is part of the DiffX library.
*
* For licensing information please see the file license.txt included in the release.
* A copy of this licence can also be found at
* http://www.opensource.org/licenses/artistic-license-2.0.php
*/
package com.topologi.diffx.xml.esc;
/**
* A singleton for escaping XML data when using the 'ASCII' encoding.
*
* @author Christophe Lauret
* @version 16 January 2007
*/
public final class XMLEscapeASCII extends XMLEscapeBase implements XMLEscape {
/**
* A static instance of the UTF8 escape class.
*/
public static final XMLEscape ASCII_ESCAPE = new XMLEscapeASCII();
/**
* The encoding used for this instance.
*/
private static final String ENCODING = "ASCII";
/**
* Prevent creation of instances
*/
private XMLEscapeASCII() {
super(ENCODING);
}
/**
* Replaces '<', '&', '"' and '\'' as well an any character that is not part of
* the standard unicode range.
*
* <pre>
* Char ::= #x9 | #xA | #xD |
* [#x20-#xD7FF] |
* [#xE000-#xFFFD] |
* [#x10000-#x10FFFF]
* </pre>
*
* {@inheritDoc}
*/
@Override
public String toAttributeValue(char[] ch, int off, int len) {
// process the rest
StringBuffer out = new StringBuffer(len + len / 10);
for (int i = off; i < off+len; i++) {
// 0x00 to 0x1F
if (ch[i] < 0x20) {
// tabs, new lines and line feeds: preserve
if (ch[i] == 0x09 || ch[i] == 0x0A || ch[i] == 0x0D) {
out.append(ch[i]);
} else {
doNothing();
// 0x20 to 0x7F
}
} else if (ch[i] < 0x80) {
switch (ch[i]) {
case '&' :
out.append("&");
break;
case '<' :
out.append("<");
break;
case '"' :
out.append(""");
break;
case '\'' :
out.append("'");
break;
// output by default
default:
out.append(ch[i]);
}
// control characters (C1): prune
} else if (ch[i] < 0xA0) {
doNothing();
// all other characters: use numerical character entity
} else {
out.append("&#x").append((int)ch[i]).append(';');
}
}
return out.toString();
}
/**
* Replace characters which are invalid in element values,
* by the corresponding entity in a given <code>String</code>.
*
* <p>these characters are:<br>
* <ul>
* <li>'&' by the ampersand entity "&"</li>
* <li>'<' by the entity "<"</li>
* </ul>
* </p>
*
* <p>Empty strings or <code>null</code> return respectively
* "" and <code>null</code>.
*
* <p>Note: this function assumes that there are no entities in
* the given String. If there are existing entities, then the
* ampersand character will be escaped by the ampersand entity.
*
* {@inheritDoc}
*/
@Override
public String toElementText(char[] ch, int off, int len) {
// process the rest
StringBuffer out = new StringBuffer(len + len / 10);
for (int i = off; i < off+len; i++) {
// 0x00 to 0x1F
if (ch[i] < 0x20) {
// tabs, new lines and line feeds: preserve
if (ch[i] == 0x09 || ch[i] == 0x0A || ch[i] == 0x0D) {
out.append(ch[i]);
} else {
doNothing();
// 0x20 to 0x7F
}
} else if (ch[i] < 0x80) {
switch (ch[i]) {
case '&' :
out.append("&");
break;
case '<' :
out.append("<");
break;
// output by default
default:
out.append(ch[i]);
}
// control characters (C1): prune
} else if (ch[i] < 0xA0) {
doNothing();
// all other characters: use numerical character entity
} else {
out.append("&#x").append((int)ch[i]).append(';');
}
}
return out.toString();
}
/**
* Does nothing.
*/
private void doNothing() {
}
}