/*
* Copyright (C) 2003-2010 eXo Platform SAS.
*
* This program is free software; you can redistribute it and/or
* modify it under the terms of the GNU Affero General Public License
* as published by the Free Software Foundation; either version 3
* of the License, or (at your option) any later version.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with this program; if not, see<http://www.gnu.org/licenses/>.
*/
package org.exoplatform.wiki.rendering.render.confluence;
import java.util.regex.Matcher;
import java.util.regex.Pattern;
import org.apache.commons.lang.StringUtils;
import org.xwiki.rendering.listener.chaining.BlockStateChainingListener;
/**
* Created by The eXo Platform SAS
* Author : viet nguyen
* viet.nguyen@exoplatform.com
* Jul 2, 2010
*/
/**
* Escape characters that would be confused for Confluence wiki syntax if they were not escaped.
*/
public class ConfluenceSyntaxEscapeHandler {
public static final Pattern STARLISTEND_PATTERN = Pattern.compile("(\\**([:;]*|1+\\.)?\\p{Blank})");
private static final Pattern LIST_PATTERN = Pattern.compile("\\p{Blank}*((\\*+[:;]*)|([1*]+\\.[:;]*)|([:;]+))\\p{Blank}+");
private static final Pattern QUOTE_PATTERN = Pattern.compile("(\\>+)");
private static final Pattern HEADER_PATTERN = Pattern.compile("\\p{Blank}*(=+)");
private static final Pattern TABLE_PATTERN = Pattern.compile("\\p{Blank}*(\\||!!)");
private static final Pattern DOUBLE_CHARS_PATTERN = Pattern.compile("\\/\\/|\\*\\*|__|--|\\^\\^|,,|##|\\\\\\\\");
public static final String ESCAPE_CHAR = "~";
private boolean beforeLink = false;
private boolean onNewLine = true;
public void setOnNewLine(boolean onNewLine) {
this.onNewLine = onNewLine;
}
public boolean isOnNewLine() {
return this.onNewLine;
}
public void escape(StringBuffer accumulatedBuffer, ConfluenceSyntaxListenerChain listenerChain, boolean escapeLastChar,
Pattern escapeFirstIfMatching) {
BlockStateChainingListener blockStateListener = listenerChain.getBlockStateChainingListener();
// Escape tilde symbol (i.e. the escape character).
// Note: This needs to be the first replacement since other replacements below also use the tilde symbol
replaceAll(accumulatedBuffer, ESCAPE_CHAR, ESCAPE_CHAR + ESCAPE_CHAR);
// When in a paragraph we need to escape symbols that are at beginning of lines and that could be confused
// with list items, headers or tables.
if (blockStateListener.isInLine() && isOnNewLine()) {
// Look for list pattern at beginning of line and escape the first character only (it's enough)
escapeFirstMatchedCharacter(LIST_PATTERN, accumulatedBuffer);
// Look for header pattern at beginning of line and escape the first character only (it's enough)
escapeFirstMatchedCharacter(HEADER_PATTERN, accumulatedBuffer);
// Look for table character patterns at beginning of line and escape the first character only (it's enough)
escapeFirstMatchedCharacter(TABLE_PATTERN, accumulatedBuffer);
// Look for quote pattern at beginning of line and escape the first character only (it's enough)
escapeFirstMatchedCharacter(QUOTE_PATTERN, accumulatedBuffer);
}
// Escape table characters
if (blockStateListener.isInTable()) {
replaceAll(accumulatedBuffer, "|", ESCAPE_CHAR + "|");
replaceAll(accumulatedBuffer, "||", ESCAPE_CHAR + "|" + ESCAPE_CHAR + "|");
}
if (escapeFirstIfMatching != null) {
escapeFirstMatchedCharacter(escapeFirstIfMatching, accumulatedBuffer);
}
// When in a header we need to escape "=" symbols since otherwise they would
// be confused for end of section characters.
if (blockStateListener.isInHeader()) {
replaceAll(accumulatedBuffer, "=", ESCAPE_CHAR + "=");
}
// Escape verbatim "{{{"
replaceAll(accumulatedBuffer, "{{{", ESCAPE_CHAR + "{" + ESCAPE_CHAR + "{" + ESCAPE_CHAR + "{");
// Escape "{{"
replaceAll(accumulatedBuffer, "{{", ESCAPE_CHAR + "{" + ESCAPE_CHAR + "{");
// Escape groups
replaceAll(accumulatedBuffer, "(((", ESCAPE_CHAR + "(" + ESCAPE_CHAR + "(" + ESCAPE_CHAR + "(");
replaceAll(accumulatedBuffer, ")))", ESCAPE_CHAR + ")" + ESCAPE_CHAR + ")" + ESCAPE_CHAR + ")");
// Escape reserved keywords
Matcher matcher = DOUBLE_CHARS_PATTERN.matcher(accumulatedBuffer.toString());
for (int i = 0; matcher.find(); i = i + 2) {
accumulatedBuffer.replace(matcher.start() + i, matcher.end() + i, ESCAPE_CHAR
+ matcher.group().charAt(0) + ESCAPE_CHAR + matcher.group().charAt(1));
}
// Escape ":" in "image:something", "attach:something" and "mailto:something"
// Note: even though there are some restriction in the URI specification as to what character is valid after
// the ":" character following the scheme we only check for characters greater than the space symbol for
// simplicity.
escapeURI(accumulatedBuffer, "image:");
escapeURI(accumulatedBuffer, "attach:");
escapeURI(accumulatedBuffer, "mailto:");
// Escape last character if we're told to do so. This is to handle cases such as:
// - onWord("hello:") followed by onFormat(ITALIC) which would lead to "hello://" if the ":" wasn't escaped
// - onWord("{") followed by onMacro() which would lead to "{{{" if the "{" wasn't escaped
if (escapeLastChar) {
accumulatedBuffer.insert(accumulatedBuffer.length() - 1, '~');
}
// Escape begin link
replaceAll(accumulatedBuffer, "[", ESCAPE_CHAR + "[");
// Escape link label
int linkLevel = getLinkLevel(listenerChain);
if (linkLevel > 0) {
// This need to be done after anything else because link label add another level of escaping (escaped as
// link label and then escaped as wiki content).
String escape = StringUtils.repeat(ESCAPE_CHAR, linkLevel);
replaceAll(accumulatedBuffer, ESCAPE_CHAR, escape + ESCAPE_CHAR);
replaceAll(accumulatedBuffer, "]", escape + "]");
replaceAll(accumulatedBuffer, "^", escape + "^");
replaceAll(accumulatedBuffer, "|", escape + "|");
}
}
private int getLinkLevel(ConfluenceSyntaxListenerChain listenerChain) {
int linkDepth = listenerChain.getBlockStateChainingListener().getLinkDepth();
if (this.beforeLink) {
--linkDepth;
}
return linkDepth;
}
public void setBeforeLink(boolean beforeLink) {
this.beforeLink = beforeLink;
}
private void escapeURI(StringBuffer accumulatedBuffer, String match) {
int pos = accumulatedBuffer.indexOf(match);
if (pos > -1 && accumulatedBuffer.length() > pos + match.length()
&& accumulatedBuffer.charAt(pos + match.length()) > 32) {
// Escape the ":" symbol
accumulatedBuffer.replace(pos + match.length() - 1, pos + match.length(), "~:");
}
}
private void replaceAll(StringBuffer accumulatedBuffer, String match, String replacement) {
int pos = -replacement.length();
while ((pos + replacement.length() < accumulatedBuffer.length())
&& ((pos = accumulatedBuffer.indexOf(match, pos + replacement.length())) != -1)) {
accumulatedBuffer.replace(pos, pos + match.length(), replacement);
}
}
private void escapeFirstMatchedCharacter(Pattern pattern, StringBuffer accumulatedBuffer) {
Matcher matcher = pattern.matcher(accumulatedBuffer);
if (matcher.lookingAt()) {
// Escape the first character
accumulatedBuffer.replace(matcher.start(1), matcher.start(1) + 1, ESCAPE_CHAR
+ matcher.group(1).charAt(0));
}
}
}