From: Michael Vogel Date: Mon, 23 Feb 2015 07:27:35 +0000 (+0100) Subject: Tests with new markdown library X-Git-Url: https://git.mxchange.org/?a=commitdiff_plain;h=b710c8bbfd4cd12a903bd75130287416f7ce5ed1;p=friendica.git Tests with new markdown library --- diff --git a/library/markdown.php b/library/markdown.php index 83082f7ca7..8958e8c842 100644 --- a/library/markdown.php +++ b/library/markdown.php @@ -1,13 +1,17 @@ text($text)); + return $html; } ?> diff --git a/library/php-markdown/License.md b/library/php-markdown/License.md new file mode 100644 index 0000000000..8a5b85447e --- /dev/null +++ b/library/php-markdown/License.md @@ -0,0 +1,36 @@ +PHP Markdown Lib +Copyright (c) 2004-2014 Michel Fortin + +All rights reserved. + +Based on Markdown +Copyright (c) 2003-2006 John Gruber + +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 "Markdown" 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. diff --git a/library/php-markdown/Michelf/Markdown.inc.php b/library/php-markdown/Michelf/Markdown.inc.php new file mode 100644 index 0000000000..8c281094ce --- /dev/null +++ b/library/php-markdown/Michelf/Markdown.inc.php @@ -0,0 +1,10 @@ + +# +# Original Markdown +# Copyright (c) 2004-2006 John Gruber +# +# +namespace Michelf; + + +# +# Markdown Parser Class +# + +class Markdown implements MarkdownInterface { + + ### Version ### + + const MARKDOWNLIB_VERSION = "1.4.1"; + + ### Simple Function Interface ### + + public static function defaultTransform($text) { + # + # Initialize the parser and return the result of its transform method. + # This will work fine for derived classes too. + # + # Take parser class on which this function was called. + $parser_class = \get_called_class(); + + # try to take parser from the static parser list + static $parser_list; + $parser =& $parser_list[$parser_class]; + + # create the parser it not already set + if (!$parser) + $parser = new $parser_class; + + # Transform text using parser. + return $parser->transform($text); + } + + ### Configuration Variables ### + + # Change to ">" for HTML output. + public $empty_element_suffix = " />"; + public $tab_width = 4; + + # Change to `true` to disallow markup or entities. + public $no_markup = false; + public $no_entities = false; + + # Predefined urls and titles for reference links and images. + public $predef_urls = array(); + public $predef_titles = array(); + + # Optional filter function for URLs + public $url_filter_func = null; + + + ### Parser Implementation ### + + # Regex to match balanced [brackets]. + # Needed to insert a maximum bracked depth while converting to PHP. + protected $nested_brackets_depth = 6; + protected $nested_brackets_re; + + protected $nested_url_parenthesis_depth = 4; + protected $nested_url_parenthesis_re; + + # Table of hash values for escaped characters: + protected $escape_chars = '\`*_{}[]()>#+-.!'; + protected $escape_chars_re; + + + public function __construct() { + # + # Constructor function. Initialize appropriate member variables. + # + $this->_initDetab(); + $this->prepareItalicsAndBold(); + + $this->nested_brackets_re = + str_repeat('(?>[^\[\]]+|\[', $this->nested_brackets_depth). + str_repeat('\])*', $this->nested_brackets_depth); + + $this->nested_url_parenthesis_re = + str_repeat('(?>[^()\s]+|\(', $this->nested_url_parenthesis_depth). + str_repeat('(?>\)))*', $this->nested_url_parenthesis_depth); + + $this->escape_chars_re = '['.preg_quote($this->escape_chars).']'; + + # Sort document, block, and span gamut in ascendent priority order. + asort($this->document_gamut); + asort($this->block_gamut); + asort($this->span_gamut); + } + + + # Internal hashes used during transformation. + protected $urls = array(); + protected $titles = array(); + protected $html_hashes = array(); + + # Status flag to avoid invalid nesting. + protected $in_anchor = false; + + + protected function setup() { + # + # Called before the transformation process starts to setup parser + # states. + # + # Clear global hashes. + $this->urls = $this->predef_urls; + $this->titles = $this->predef_titles; + $this->html_hashes = array(); + + $this->in_anchor = false; + } + + protected function teardown() { + # + # Called after the transformation process to clear any variable + # which may be taking up memory unnecessarly. + # + $this->urls = array(); + $this->titles = array(); + $this->html_hashes = array(); + } + + + public function transform($text) { + # + # Main function. Performs some preprocessing on the input text + # and pass it through the document gamut. + # + $this->setup(); + + # Remove UTF-8 BOM and marker character in input, if present. + $text = preg_replace('{^\xEF\xBB\xBF|\x1A}', '', $text); + + # Standardize line endings: + # DOS to Unix and Mac to Unix + $text = preg_replace('{\r\n?}', "\n", $text); + + # Make sure $text ends with a couple of newlines: + $text .= "\n\n"; + + # Convert all tabs to spaces. + $text = $this->detab($text); + + # Turn block-level HTML blocks into hash entries + $text = $this->hashHTMLBlocks($text); + + # Strip any lines consisting only of spaces and tabs. + # This makes subsequent regexen easier to write, because we can + # match consecutive blank lines with /\n+/ instead of something + # contorted like /[ ]*\n+/ . + $text = preg_replace('/^[ ]+$/m', '', $text); + + # Run document gamut methods. + foreach ($this->document_gamut as $method => $priority) { + $text = $this->$method($text); + } + + $this->teardown(); + + return $text . "\n"; + } + + protected $document_gamut = array( + # Strip link definitions, store in hashes. + "stripLinkDefinitions" => 20, + + "runBasicBlockGamut" => 30, + ); + + + protected function stripLinkDefinitions($text) { + # + # Strips link definitions from text, stores the URLs and titles in + # hash references. + # + $less_than_tab = $this->tab_width - 1; + + # Link defs are in the form: ^[id]: url "optional title" + $text = preg_replace_callback('{ + ^[ ]{0,'.$less_than_tab.'}\[(.+)\][ ]?: # id = $1 + [ ]* + \n? # maybe *one* newline + [ ]* + (?: + <(.+?)> # url = $2 + | + (\S+?) # url = $3 + ) + [ ]* + \n? # maybe one newline + [ ]* + (?: + (?<=\s) # lookbehind for whitespace + ["(] + (.*?) # title = $4 + [")] + [ ]* + )? # title is optional + (?:\n+|\Z) + }xm', + array($this, '_stripLinkDefinitions_callback'), + $text); + return $text; + } + protected function _stripLinkDefinitions_callback($matches) { + $link_id = strtolower($matches[1]); + $url = $matches[2] == '' ? $matches[3] : $matches[2]; + $this->urls[$link_id] = $url; + $this->titles[$link_id] =& $matches[4]; + return ''; # String that will replace the block + } + + + protected function hashHTMLBlocks($text) { + if ($this->no_markup) return $text; + + $less_than_tab = $this->tab_width - 1; + + # Hashify HTML blocks: + # We only want to do this for block-level HTML tags, such as headers, + # lists, and tables. That's because we still want to wrap

s around + # "paragraphs" that are wrapped in non-block-level tags, such as anchors, + # phrase emphasis, and spans. The list of tags we're looking for is + # hard-coded: + # + # * List "a" is made of tags which can be both inline or block-level. + # These will be treated block-level when the start tag is alone on + # its line, otherwise they're not matched here and will be taken as + # inline later. + # * List "b" is made of tags which are always block-level; + # + $block_tags_a_re = 'ins|del'; + $block_tags_b_re = 'p|div|h[1-6]|blockquote|pre|table|dl|ol|ul|address|'. + 'script|noscript|style|form|fieldset|iframe|math|svg|'. + 'article|section|nav|aside|hgroup|header|footer|'. + 'figure'; + + # Regular expression for the content of a block tag. + $nested_tags_level = 4; + $attr = ' + (?> # optional tag attributes + \s # starts with whitespace + (?> + [^>"/]+ # text outside quotes + | + /+(?!>) # slash not followed by ">" + | + "[^"]*" # text inside double quotes (tolerate ">") + | + \'[^\']*\' # text inside single quotes (tolerate ">") + )* + )? + '; + $content = + str_repeat(' + (?> + [^<]+ # content without tag + | + <\2 # nested opening tag + '.$attr.' # attributes + (?> + /> + | + >', $nested_tags_level). # end of opening tag + '.*?'. # last level nested tag content + str_repeat(' + # closing nested tag + ) + | + <(?!/\2\s*> # other tags with a different name + ) + )*', + $nested_tags_level); + $content2 = str_replace('\2', '\3', $content); + + # First, look for nested blocks, e.g.: + #

+ #
+ # tags for inner block must be indented. + #
+ #
+ # + # The outermost tags must start at the left margin for this to match, and + # the inner nested divs must be indented. + # We need to do this before the next, more liberal match, because the next + # match will start at the first `
` and stop at the first `
`. + $text = preg_replace_callback('{(?> + (?> + (?<=\n) # Starting on its own line + | # or + \A\n? # the at beginning of the doc + ) + ( # save in $1 + + # Match from `\n` to `\n`, handling nested tags + # in between. + + [ ]{0,'.$less_than_tab.'} + <('.$block_tags_b_re.')# start tag = $2 + '.$attr.'> # attributes followed by > and \n + '.$content.' # content, support nesting + # the matching end tag + [ ]* # trailing spaces/tabs + (?=\n+|\Z) # followed by a newline or end of document + + | # Special version for tags of group a. + + [ ]{0,'.$less_than_tab.'} + <('.$block_tags_a_re.')# start tag = $3 + '.$attr.'>[ ]*\n # attributes followed by > + '.$content2.' # content, support nesting + # the matching end tag + [ ]* # trailing spaces/tabs + (?=\n+|\Z) # followed by a newline or end of document + + | # Special case just for
. It was easier to make a special + # case than to make the other regex more complicated. + + [ ]{0,'.$less_than_tab.'} + <(hr) # start tag = $2 + '.$attr.' # attributes + /?> # the matching end tag + [ ]* + (?=\n{2,}|\Z) # followed by a blank line or end of document + + | # Special case for standalone HTML comments: + + [ ]{0,'.$less_than_tab.'} + (?s: + + ) + [ ]* + (?=\n{2,}|\Z) # followed by a blank line or end of document + + | # PHP and ASP-style processor instructions ( + ) + [ ]* + (?=\n{2,}|\Z) # followed by a blank line or end of document + + ) + )}Sxmi', + array($this, '_hashHTMLBlocks_callback'), + $text); + + return $text; + } + protected function _hashHTMLBlocks_callback($matches) { + $text = $matches[1]; + $key = $this->hashBlock($text); + return "\n\n$key\n\n"; + } + + + protected function hashPart($text, $boundary = 'X') { + # + # Called whenever a tag must be hashed when a function insert an atomic + # element in the text stream. Passing $text to through this function gives + # a unique text-token which will be reverted back when calling unhash. + # + # The $boundary argument specify what character should be used to surround + # the token. By convension, "B" is used for block elements that needs not + # to be wrapped into paragraph tags at the end, ":" is used for elements + # that are word separators and "X" is used in the general case. + # + # Swap back any tag hash found in $text so we do not have to `unhash` + # multiple times at the end. + $text = $this->unhash($text); + + # Then hash the block. + static $i = 0; + $key = "$boundary\x1A" . ++$i . $boundary; + $this->html_hashes[$key] = $text; + return $key; # String that will replace the tag. + } + + + protected function hashBlock($text) { + # + # Shortcut function for hashPart with block-level boundaries. + # + return $this->hashPart($text, 'B'); + } + + + protected $block_gamut = array( + # + # These are all the transformations that form block-level + # tags like paragraphs, headers, and list items. + # + "doHeaders" => 10, + "doHorizontalRules" => 20, + + "doLists" => 40, + "doCodeBlocks" => 50, + "doBlockQuotes" => 60, + ); + + protected function runBlockGamut($text) { + # + # Run block gamut tranformations. + # + # We need to escape raw HTML in Markdown source before doing anything + # else. This need to be done for each block, and not only at the + # begining in the Markdown function since hashed blocks can be part of + # list items and could have been indented. Indented blocks would have + # been seen as a code block in a previous pass of hashHTMLBlocks. + $text = $this->hashHTMLBlocks($text); + + return $this->runBasicBlockGamut($text); + } + + protected function runBasicBlockGamut($text) { + # + # Run block gamut tranformations, without hashing HTML blocks. This is + # useful when HTML blocks are known to be already hashed, like in the first + # whole-document pass. + # + foreach ($this->block_gamut as $method => $priority) { + $text = $this->$method($text); + } + + # Finally form paragraph and restore hashed blocks. + $text = $this->formParagraphs($text); + + return $text; + } + + + protected function doHorizontalRules($text) { + # Do Horizontal Rules: + return preg_replace( + '{ + ^[ ]{0,3} # Leading space + ([-*_]) # $1: First marker + (?> # Repeated marker group + [ ]{0,2} # Zero, one, or two spaces. + \1 # Marker character + ){2,} # Group repeated at least twice + [ ]* # Tailing spaces + $ # End of line. + }mx', + "\n".$this->hashBlock("empty_element_suffix")."\n", + $text); + } + + + protected $span_gamut = array( + # + # These are all the transformations that occur *within* block-level + # tags like paragraphs, headers, and list items. + # + # Process character escapes, code spans, and inline HTML + # in one shot. + "parseSpan" => -30, + + # Process anchor and image tags. Images must come first, + # because ![foo][f] looks like an anchor. + "doImages" => 10, + "doAnchors" => 20, + + # Make links out of things like `` + # Must come after doAnchors, because you can use < and > + # delimiters in inline links like [this](). + "doAutoLinks" => 30, + "encodeAmpsAndAngles" => 40, + + "doItalicsAndBold" => 50, + "doHardBreaks" => 60, + ); + + protected function runSpanGamut($text) { + # + # Run span gamut tranformations. + # + foreach ($this->span_gamut as $method => $priority) { + $text = $this->$method($text); + } + + return $text; + } + + + protected function doHardBreaks($text) { + # Do hard breaks: + return preg_replace_callback('/ {2,}\n/', + array($this, '_doHardBreaks_callback'), $text); + } + protected function _doHardBreaks_callback($matches) { + return $this->hashPart("empty_element_suffix\n"); + } + + + protected function doAnchors($text) { + # + # Turn Markdown link shortcuts into XHTML tags. + # + if ($this->in_anchor) return $text; + $this->in_anchor = true; + + # + # First, handle reference-style links: [link text] [id] + # + $text = preg_replace_callback('{ + ( # wrap whole match in $1 + \[ + ('.$this->nested_brackets_re.') # link text = $2 + \] + + [ ]? # one optional space + (?:\n[ ]*)? # one optional newline followed by spaces + + \[ + (.*?) # id = $3 + \] + ) + }xs', + array($this, '_doAnchors_reference_callback'), $text); + + # + # Next, inline-style links: [link text](url "optional title") + # + $text = preg_replace_callback('{ + ( # wrap whole match in $1 + \[ + ('.$this->nested_brackets_re.') # link text = $2 + \] + \( # literal paren + [ \n]* + (?: + <(.+?)> # href = $3 + | + ('.$this->nested_url_parenthesis_re.') # href = $4 + ) + [ \n]* + ( # $5 + ([\'"]) # quote char = $6 + (.*?) # Title = $7 + \6 # matching quote + [ \n]* # ignore any spaces/tabs between closing quote and ) + )? # title is optional + \) + ) + }xs', + array($this, '_doAnchors_inline_callback'), $text); + + # + # Last, handle reference-style shortcuts: [link text] + # These must come last in case you've also got [link text][1] + # or [link text](/foo) + # + $text = preg_replace_callback('{ + ( # wrap whole match in $1 + \[ + ([^\[\]]+) # link text = $2; can\'t contain [ or ] + \] + ) + }xs', + array($this, '_doAnchors_reference_callback'), $text); + + $this->in_anchor = false; + return $text; + } + protected function _doAnchors_reference_callback($matches) { + $whole_match = $matches[1]; + $link_text = $matches[2]; + $link_id =& $matches[3]; + + if ($link_id == "") { + # for shortcut links like [this][] or [this]. + $link_id = $link_text; + } + + # lower-case and turn embedded newlines into spaces + $link_id = strtolower($link_id); + $link_id = preg_replace('{[ ]?\n}', ' ', $link_id); + + if (isset($this->urls[$link_id])) { + $url = $this->urls[$link_id]; + $url = $this->encodeURLAttribute($url); + + $result = "titles[$link_id] ) ) { + $title = $this->titles[$link_id]; + $title = $this->encodeAttribute($title); + $result .= " title=\"$title\""; + } + + $link_text = $this->runSpanGamut($link_text); + $result .= ">$link_text"; + $result = $this->hashPart($result); + } + else { + $result = $whole_match; + } + return $result; + } + protected function _doAnchors_inline_callback($matches) { + $whole_match = $matches[1]; + $link_text = $this->runSpanGamut($matches[2]); + $url = $matches[3] == '' ? $matches[4] : $matches[3]; + $title =& $matches[7]; + + // if the URL was of the form it got caught by the HTML + // tag parser and hashed. Need to reverse the process before using the URL. + $unhashed = $this->unhash($url); + if ($unhashed != $url) + $url = preg_replace('/^<(.*)>$/', '\1', $unhashed); + + $url = $this->encodeURLAttribute($url); + + $result = "encodeAttribute($title); + $result .= " title=\"$title\""; + } + + $link_text = $this->runSpanGamut($link_text); + $result .= ">$link_text"; + + return $this->hashPart($result); + } + + + protected function doImages($text) { + # + # Turn Markdown image shortcuts into tags. + # + # + # First, handle reference-style labeled images: ![alt text][id] + # + $text = preg_replace_callback('{ + ( # wrap whole match in $1 + !\[ + ('.$this->nested_brackets_re.') # alt text = $2 + \] + + [ ]? # one optional space + (?:\n[ ]*)? # one optional newline followed by spaces + + \[ + (.*?) # id = $3 + \] + + ) + }xs', + array($this, '_doImages_reference_callback'), $text); + + # + # Next, handle inline images: ![alt text](url "optional title") + # Don't forget: encode * and _ + # + $text = preg_replace_callback('{ + ( # wrap whole match in $1 + !\[ + ('.$this->nested_brackets_re.') # alt text = $2 + \] + \s? # One optional whitespace character + \( # literal paren + [ \n]* + (?: + <(\S*)> # src url = $3 + | + ('.$this->nested_url_parenthesis_re.') # src url = $4 + ) + [ \n]* + ( # $5 + ([\'"]) # quote char = $6 + (.*?) # title = $7 + \6 # matching quote + [ \n]* + )? # title is optional + \) + ) + }xs', + array($this, '_doImages_inline_callback'), $text); + + return $text; + } + protected function _doImages_reference_callback($matches) { + $whole_match = $matches[1]; + $alt_text = $matches[2]; + $link_id = strtolower($matches[3]); + + if ($link_id == "") { + $link_id = strtolower($alt_text); # for shortcut links like ![this][]. + } + + $alt_text = $this->encodeAttribute($alt_text); + if (isset($this->urls[$link_id])) { + $url = $this->encodeURLAttribute($this->urls[$link_id]); + $result = "\"$alt_text\"";titles[$link_id])) { + $title = $this->titles[$link_id]; + $title = $this->encodeAttribute($title); + $result .= " title=\"$title\""; + } + $result .= $this->empty_element_suffix; + $result = $this->hashPart($result); + } + else { + # If there's no such link ID, leave intact: + $result = $whole_match; + } + + return $result; + } + protected function _doImages_inline_callback($matches) { + $whole_match = $matches[1]; + $alt_text = $matches[2]; + $url = $matches[3] == '' ? $matches[4] : $matches[3]; + $title =& $matches[7]; + + $alt_text = $this->encodeAttribute($alt_text); + $url = $this->encodeURLAttribute($url); + $result = "\"$alt_text\"";encodeAttribute($title); + $result .= " title=\"$title\""; # $title already quoted + } + $result .= $this->empty_element_suffix; + + return $this->hashPart($result); + } + + + protected function doHeaders($text) { + # Setext-style headers: + # Header 1 + # ======== + # + # Header 2 + # -------- + # + $text = preg_replace_callback('{ ^(.+?)[ ]*\n(=+|-+)[ ]*\n+ }mx', + array($this, '_doHeaders_callback_setext'), $text); + + # atx-style headers: + # # Header 1 + # ## Header 2 + # ## Header 2 with closing hashes ## + # ... + # ###### Header 6 + # + $text = preg_replace_callback('{ + ^(\#{1,6}) # $1 = string of #\'s + [ ]* + (.+?) # $2 = Header text + [ ]* + \#* # optional closing #\'s (not counted) + \n+ + }xm', + array($this, '_doHeaders_callback_atx'), $text); + + return $text; + } + protected function _doHeaders_callback_setext($matches) { + # Terrible hack to check we haven't found an empty list item. + if ($matches[2] == '-' && preg_match('{^-(?: |$)}', $matches[1])) + return $matches[0]; + + $level = $matches[2]{0} == '=' ? 1 : 2; + $block = "".$this->runSpanGamut($matches[1]).""; + return "\n" . $this->hashBlock($block) . "\n\n"; + } + protected function _doHeaders_callback_atx($matches) { + $level = strlen($matches[1]); + $block = "".$this->runSpanGamut($matches[2]).""; + return "\n" . $this->hashBlock($block) . "\n\n"; + } + + + protected function doLists($text) { + # + # Form HTML ordered (numbered) and unordered (bulleted) lists. + # + $less_than_tab = $this->tab_width - 1; + + # Re-usable patterns to match list item bullets and number markers: + $marker_ul_re = '[*+-]'; + $marker_ol_re = '\d+[\.]'; + + $markers_relist = array( + $marker_ul_re => $marker_ol_re, + $marker_ol_re => $marker_ul_re, + ); + + foreach ($markers_relist as $marker_re => $other_marker_re) { + # Re-usable pattern to match any entirel ul or ol list: + $whole_list_re = ' + ( # $1 = whole list + ( # $2 + ([ ]{0,'.$less_than_tab.'}) # $3 = number of spaces + ('.$marker_re.') # $4 = first list item marker + [ ]+ + ) + (?s:.+?) + ( # $5 + \z + | + \n{2,} + (?=\S) + (?! # Negative lookahead for another list item marker + [ ]* + '.$marker_re.'[ ]+ + ) + | + (?= # Lookahead for another kind of list + \n + \3 # Must have the same indentation + '.$other_marker_re.'[ ]+ + ) + ) + ) + '; // mx + + # We use a different prefix before nested lists than top-level lists. + # See extended comment in _ProcessListItems(). + + if ($this->list_level) { + $text = preg_replace_callback('{ + ^ + '.$whole_list_re.' + }mx', + array($this, '_doLists_callback'), $text); + } + else { + $text = preg_replace_callback('{ + (?:(?<=\n)\n|\A\n?) # Must eat the newline + '.$whole_list_re.' + }mx', + array($this, '_doLists_callback'), $text); + } + } + + return $text; + } + protected function _doLists_callback($matches) { + # Re-usable patterns to match list item bullets and number markers: + $marker_ul_re = '[*+-]'; + $marker_ol_re = '\d+[\.]'; + $marker_any_re = "(?:$marker_ul_re|$marker_ol_re)"; + + $list = $matches[1]; + $list_type = preg_match("/$marker_ul_re/", $matches[4]) ? "ul" : "ol"; + + $marker_any_re = ( $list_type == "ul" ? $marker_ul_re : $marker_ol_re ); + + $list .= "\n"; + $result = $this->processListItems($list, $marker_any_re); + + $result = $this->hashBlock("<$list_type>\n" . $result . ""); + return "\n". $result ."\n\n"; + } + + protected $list_level = 0; + + protected function processListItems($list_str, $marker_any_re) { + # + # Process the contents of a single ordered or unordered list, splitting it + # into individual list items. + # + # The $this->list_level global keeps track of when we're inside a list. + # Each time we enter a list, we increment it; when we leave a list, + # we decrement. If it's zero, we're not in a list anymore. + # + # We do this because when we're not inside a list, we want to treat + # something like this: + # + # I recommend upgrading to version + # 8. Oops, now this line is treated + # as a sub-list. + # + # As a single paragraph, despite the fact that the second line starts + # with a digit-period-space sequence. + # + # Whereas when we're inside a list (or sub-list), that line will be + # treated as the start of a sub-list. What a kludge, huh? This is + # an aspect of Markdown's syntax that's hard to parse perfectly + # without resorting to mind-reading. Perhaps the solution is to + # change the syntax rules such that sub-lists must start with a + # starting cardinal number; e.g. "1." or "a.". + + $this->list_level++; + + # trim trailing blank lines: + $list_str = preg_replace("/\n{2,}\\z/", "\n", $list_str); + + $list_str = preg_replace_callback('{ + (\n)? # leading line = $1 + (^[ ]*) # leading whitespace = $2 + ('.$marker_any_re.' # list marker and space = $3 + (?:[ ]+|(?=\n)) # space only required if item is not empty + ) + ((?s:.*?)) # list item text = $4 + (?:(\n+(?=\n))|\n) # tailing blank line = $5 + (?= \n* (\z | \2 ('.$marker_any_re.') (?:[ ]+|(?=\n)))) + }xm', + array($this, '_processListItems_callback'), $list_str); + + $this->list_level--; + return $list_str; + } + protected function _processListItems_callback($matches) { + $item = $matches[4]; + $leading_line =& $matches[1]; + $leading_space =& $matches[2]; + $marker_space = $matches[3]; + $tailing_blank_line =& $matches[5]; + + if ($leading_line || $tailing_blank_line || + preg_match('/\n{2,}/', $item)) + { + # Replace marker with the appropriate whitespace indentation + $item = $leading_space . str_repeat(' ', strlen($marker_space)) . $item; + $item = $this->runBlockGamut($this->outdent($item)."\n"); + } + else { + # Recursion for sub-lists: + $item = $this->doLists($this->outdent($item)); + $item = preg_replace('/\n+$/', '', $item); + $item = $this->runSpanGamut($item); + } + + return "
  • " . $item . "
    • \n"; + } + + + protected function doCodeBlocks($text) { + # + # Process Markdown `
    ` blocks.
+	#
+		$text = preg_replace_callback('{
+				(?:\n\n|\A\n?)
+				(	            # $1 = the code block -- one or more lines, starting with a space/tab
+				  (?>
+					[ ]{'.$this->tab_width.'}  # Lines must start with a tab or a tab-width of spaces
+					.*\n+
+				  )+
+				)
+				((?=^[ ]{0,'.$this->tab_width.'}\S)|\Z)	# Lookahead for non-space at line-start, or end of doc
+			}xm',
+			array($this, '_doCodeBlocks_callback'), $text);
+
+		return $text;
+	}
+	protected function _doCodeBlocks_callback($matches) {
+		$codeblock = $matches[1];
+
+		$codeblock = $this->outdent($codeblock);
+		$codeblock = htmlspecialchars($codeblock, ENT_NOQUOTES);
+
+		# trim leading newlines and trailing newlines
+		$codeblock = preg_replace('/\A\n+|\n+\z/', '', $codeblock);
+
+		$codeblock = "
    $codeblock\n
    ";
+		return "\n\n".$this->hashBlock($codeblock)."\n\n";
+	}
+
+
+	protected function makeCodeSpan($code) {
+	#
+	# Create a code span markup for $code. Called from handleSpanToken.
+	#
+		$code = htmlspecialchars(trim($code), ENT_NOQUOTES);
+		return $this->hashPart("$code");
+	}
+
+
+	protected $em_relist = array(
+		''  => '(?:(? '(? '(? '(?:(? '(? '(? '(?:(? '(? '(?em_relist as $em => $em_re) {
+			foreach ($this->strong_relist as $strong => $strong_re) {
+				# Construct list of allowed token expressions.
+				$token_relist = array();
+				if (isset($this->em_strong_relist["$em$strong"])) {
+					$token_relist[] = $this->em_strong_relist["$em$strong"];
+				}
+				$token_relist[] = $em_re;
+				$token_relist[] = $strong_re;
+				
+				# Construct master expression from list.
+				$token_re = '{('. implode('|', $token_relist) .')}';
+				$this->em_strong_prepared_relist["$em$strong"] = $token_re;
+			}
+		}
+	}
+	
+	protected function doItalicsAndBold($text) {
+		$token_stack = array('');
+		$text_stack = array('');
+		$em = '';
+		$strong = '';
+		$tree_char_em = false;
+		
+		while (1) {
+			#
+			# Get prepared regular expression for seraching emphasis tokens
+			# in current context.
+			#
+			$token_re = $this->em_strong_prepared_relist["$em$strong"];
+			
+			#
+			# Each loop iteration search for the next emphasis token. 
+			# Each token is then passed to handleSpanToken.
+			#
+			$parts = preg_split($token_re, $text, 2, PREG_SPLIT_DELIM_CAPTURE);
+			$text_stack[0] .= $parts[0];
+			$token =& $parts[1];
+			$text =& $parts[2];
+			
+			if (empty($token)) {
+				# Reached end of text span: empty stack without emitting.
+				# any more emphasis.
+				while ($token_stack[0]) {
+					$text_stack[1] .= array_shift($token_stack);
+					$text_stack[0] .= array_shift($text_stack);
+				}
+				break;
+			}
+			
+			$token_len = strlen($token);
+			if ($tree_char_em) {
+				# Reached closing marker while inside a three-char emphasis.
+				if ($token_len == 3) {
+					# Three-char closing marker, close em and strong.
+					array_shift($token_stack);
+					$span = array_shift($text_stack);
+					$span = $this->runSpanGamut($span);
+					$span = "$span";
+					$text_stack[0] .= $this->hashPart($span);
+					$em = '';
+					$strong = '';
+				} else {
+					# Other closing marker: close one em or strong and
+					# change current token state to match the other
+					$token_stack[0] = str_repeat($token{0}, 3-$token_len);
+					$tag = $token_len == 2 ? "strong" : "em";
+					$span = $text_stack[0];
+					$span = $this->runSpanGamut($span);
+					$span = "<$tag>$span";
+					$text_stack[0] = $this->hashPart($span);
+					$$tag = ''; # $$tag stands for $em or $strong
+				}
+				$tree_char_em = false;
+			} else if ($token_len == 3) {
+				if ($em) {
+					# Reached closing marker for both em and strong.
+					# Closing strong marker:
+					for ($i = 0; $i < 2; ++$i) {
+						$shifted_token = array_shift($token_stack);
+						$tag = strlen($shifted_token) == 2 ? "strong" : "em";
+						$span = array_shift($text_stack);
+						$span = $this->runSpanGamut($span);
+						$span = "<$tag>$span";
+						$text_stack[0] .= $this->hashPart($span);
+						$$tag = ''; # $$tag stands for $em or $strong
+					}
+				} else {
+					# Reached opening three-char emphasis marker. Push on token 
+					# stack; will be handled by the special condition above.
+					$em = $token{0};
+					$strong = "$em$em";
+					array_unshift($token_stack, $token);
+					array_unshift($text_stack, '');
+					$tree_char_em = true;
+				}
+			} else if ($token_len == 2) {
+				if ($strong) {
+					# Unwind any dangling emphasis marker:
+					if (strlen($token_stack[0]) == 1) {
+						$text_stack[1] .= array_shift($token_stack);
+						$text_stack[0] .= array_shift($text_stack);
+					}
+					# Closing strong marker:
+					array_shift($token_stack);
+					$span = array_shift($text_stack);
+					$span = $this->runSpanGamut($span);
+					$span = "$span";
+					$text_stack[0] .= $this->hashPart($span);
+					$strong = '';
+				} else {
+					array_unshift($token_stack, $token);
+					array_unshift($text_stack, '');
+					$strong = $token;
+				}
+			} else {
+				# Here $token_len == 1
+				if ($em) {
+					if (strlen($token_stack[0]) == 1) {
+						# Closing emphasis marker:
+						array_shift($token_stack);
+						$span = array_shift($text_stack);
+						$span = $this->runSpanGamut($span);
+						$span = "$span";
+						$text_stack[0] .= $this->hashPart($span);
+						$em = '';
+					} else {
+						$text_stack[0] .= $token;
+					}
+				} else {
+					array_unshift($token_stack, $token);
+					array_unshift($text_stack, '');
+					$em = $token;
+				}
+			}
+		}
+		return $text_stack[0];
+	}
+
+
+	protected function doBlockQuotes($text) {
+		$text = preg_replace_callback('/
+			  (								# Wrap whole match in $1
+				(?>
+				  ^[ ]*>[ ]?			# ">" at the start of a line
+					.+\n					# rest of the first line
+				  (.+\n)*					# subsequent consecutive lines
+				  \n*						# blanks
+				)+
+			  )
+			/xm',
+			array($this, '_doBlockQuotes_callback'), $text);
+
+		return $text;
+	}
+	protected function _doBlockQuotes_callback($matches) {
+		$bq = $matches[1];
+		# trim one level of quoting - trim whitespace-only lines
+		$bq = preg_replace('/^[ ]*>[ ]?|^[ ]+$/m', '', $bq);
+		$bq = $this->runBlockGamut($bq);		# recurse
+
+		$bq = preg_replace('/^/m', "  ", $bq);
+		# These leading spaces cause problem with 
     content, 
+		# so we need to fix that:
+		$bq = preg_replace_callback('{(\s*
    .+?
    )}sx', 
+			array($this, '_doBlockQuotes_callback2'), $bq);
+
+		return "\n". $this->hashBlock("
    \n$bq\n
    ")."\n\n";
+	}
+	protected function _doBlockQuotes_callback2($matches) {
+		$pre = $matches[1];
+		$pre = preg_replace('/^  /m', '', $pre);
+		return $pre;
+	}
+
+
+	protected function formParagraphs($text) {
+	#
+	#	Params:
+	#		$text - string to process with html 
     tags
+	#
+		# Strip leading and trailing lines:
+		$text = preg_replace('/\A\n+|\n+\z/', '', $text);
+
+		$grafs = preg_split('/\n{2,}/', $text, -1, PREG_SPLIT_NO_EMPTY);
+
+		#
+		# Wrap 
     tags and unhashify HTML blocks
+		#
+		foreach ($grafs as $key => $value) {
+			if (!preg_match('/^B\x1A[0-9]+B$/', $value)) {
+				# Is a paragraph.
+				$value = $this->runSpanGamut($value);
+				$value = preg_replace('/^([ ]*)/', "
    ", $value);
+				$value .= "
    ";
+				$grafs[$key] = $this->unhash($value);
+			}
+			else {
+				# Is a block.
+				# Modify elements of @grafs in-place...
+				$graf = $value;
+				$block = $this->html_hashes[$graf];
+				$graf = $block;
+//				if (preg_match('{
+//					\A
+//					(							# $1 = 
     tag
+//					  
    ]*
+//					  \b
+//					  markdown\s*=\s*  ([\'"])	#	$2 = attr quote char
+//					  1
+//					  \2
+//					  [^>]*
+//					  >
+//					)
+//					(							# $3 = contents
+//					.*
+//					)
+//					(
    )					# $4 = closing tag
+//					\z
+//					}xs', $block, $matches))
+//				{
+//					list(, $div_open, , $div_content, $div_close) = $matches;
+//
+//					# We can't call Markdown(), because that resets the hash;
+//					# that initialization code should be pulled into its own sub, though.
+//					$div_content = $this->hashHTMLBlocks($div_content);
+//					
+//					# Run document gamut methods on the content.
+//					foreach ($this->document_gamut as $method => $priority) {
+//						$div_content = $this->$method($div_content);
+//					}
+//
+//					$div_open = preg_replace(
+//						'{\smarkdown\s*=\s*([\'"]).+?\1}', '', $div_open);
+//
+//					$graf = $div_open . "\n" . $div_content . "\n" . $div_close;
+//				}
+				$grafs[$key] = $graf;
+			}
+		}
+
+		return implode("\n\n", $grafs);
+	}
+
+
+	protected function encodeAttribute($text) {
+	#
+	# Encode text for a double-quoted HTML attribute. This function
+	# is *not* suitable for attributes enclosed in single quotes.
+	#
+		$text = $this->encodeAmpsAndAngles($text);
+		$text = str_replace('"', '"', $text);
+		return $text;
+	}
+
+
+	protected function encodeURLAttribute($url, &$text = null) {
+	#
+	# Encode text for a double-quoted HTML attribute containing a URL,
+	# applying the URL filter if set. Also generates the textual
+	# representation for the URL (removing mailto: or tel:) storing it in $text.
+	# This function is *not* suitable for attributes enclosed in single quotes.
+	#
+		if ($this->url_filter_func)
+			$url = call_user_func($this->url_filter_func, $url);
+
+		if (preg_match('{^mailto:}i', $url))
+			$url = $this->encodeEntityObfuscatedAttribute($url, $text, 7);
+		else if (preg_match('{^tel:}i', $url))
+		{
+			$url = $this->encodeAttribute($url);
+			$text = substr($url, 4);
+		}
+		else
+		{
+			$url = $this->encodeAttribute($url);
+			$text = $url;
+		}
+
+		return $url;
+	}
+	
+	
+	protected function encodeAmpsAndAngles($text) {
+	#
+	# Smart processing for ampersands and angle brackets that need to 
+	# be encoded. Valid character entities are left alone unless the
+	# no-entities mode is set.
+	#
+		if ($this->no_entities) {
+			$text = str_replace('&', '&', $text);
+		} else {
+			# Ampersand-encoding based entirely on Nat Irons's Amputator
+			# MT plugin: 
+			$text = preg_replace('/&(?!#?[xX]?(?:[0-9a-fA-F]+|\w+);)/', 
+								'&', $text);
+		}
+		# Encode remaining <'s
+		$text = str_replace('<', '<', $text);
+
+		return $text;
+	}
+
+
+	protected function doAutoLinks($text) {
+		$text = preg_replace_callback('{<((https?|ftp|dict|tel):[^\'">\s]+)>}i',
+			array($this, '_doAutoLinks_url_callback'), $text);
+
+		# Email addresses: 
+		$text = preg_replace_callback('{
+			<
+			(?:mailto:)?
+			(
+				(?:
+					[-!#$%&\'*+/=?^_`.{|}~\w\x80-\xFF]+
+				|
+					".*?"
+				)
+				\@
+				(?:
+					[-a-z0-9\x80-\xFF]+(\.[-a-z0-9\x80-\xFF]+)*\.[a-z]+
+				|
+					\[[\d.a-fA-F:]+\]	# IPv4 & IPv6
+				)
+			)
+			>
+			}xi',
+			array($this, '_doAutoLinks_email_callback'), $text);
+
+		return $text;
+	}
+	protected function _doAutoLinks_url_callback($matches) {
+		$url = $this->encodeURLAttribute($matches[1], $text);
+		$link = "$text";
+		return $this->hashPart($link);
+	}
+	protected function _doAutoLinks_email_callback($matches) {
+		$addr = $matches[1];
+		$url = $this->encodeURLAttribute("mailto:$addr", $text);
+		$link = "$text";
+		return $this->hashPart($link);
+	}
+
+
+	protected function encodeEntityObfuscatedAttribute($text, &$tail = null, $head_length = 0) {
+	#
+	#	Input: some text to obfuscate, e.g. "mailto:foo@example.com"
+	#
+	#	Output: the same text but with most characters encoded as either a
+	#		decimal or hex entity, in the hopes of foiling most address
+	#		harvesting spam bots. E.g.:
+	#
+	#        mailto:foo
+	#        @example.co
+	#        m
+	#
+	#	Note: the additional output $tail is assigned the same value as the
+	#	ouput, minus the number of characters specified by $head_length.
+	#
+	#	Based by a filter by Matthew Wickline, posted to BBEdit-Talk.
+	#   With some optimizations by Milian Wolff. Forced encoding of HTML
+	#	attribute special characters by Allan Odgaard.
+	#
+		if ($text == "") return $tail = "";
+
+		$chars = preg_split('/(? $char) {
+			$ord = ord($char);
+			# Ignore non-ascii chars.
+			if ($ord < 128) {
+				$r = ($seed * (1 + $key)) % 100; # Pseudo-random function.
+				# roughly 10% raw, 45% hex, 45% dec
+				# '@' *must* be encoded. I insist.
+				# '"' and '>' have to be encoded inside the attribute
+				if ($r > 90 && strpos('@"&>', $char) === false) /* do nothing */;
+				else if ($r < 45) $chars[$key] = '&#x'.dechex($ord).';';
+				else              $chars[$key] = '&#'.$ord.';';
+			}
+		}
+
+		$text = implode('', $chars);
+		$tail = $head_length ? implode('', array_slice($chars, $head_length)) : $text;
+
+		return $text;
+	}
+
+
+	protected function parseSpan($str) {
+	#
+	# Take the string $str and parse it into tokens, hashing embeded HTML,
+	# escaped characters and handling code spans.
+	#
+		$output = '';
+		
+		$span_re = '{
+				(
+					\\\\'.$this->escape_chars_re.'
+				|
+					(?no_markup ? '' : '
+				|
+							# comment
+				|
+					<\?.*?\?> | <%.*?%>		# processing instruction
+				|
+					<[!$]?[-a-zA-Z0-9:_]+	# regular tags
+					(?>
+						\s
+						(?>[^"\'>]+|"[^"]*"|\'[^\']*\')*
+					)?
+					>
+				|
+					<[-a-zA-Z0-9:_]+\s*/> # xml-style empty tag
+				|
+					 # closing tag
+			').'
+				)
+				}xs';
+
+		while (1) {
+			#
+			# Each loop iteration seach for either the next tag, the next 
+			# openning code span marker, or the next escaped character. 
+			# Each token is then passed to handleSpanToken.
+			#
+			$parts = preg_split($span_re, $str, 2, PREG_SPLIT_DELIM_CAPTURE);
+			
+			# Create token from text preceding tag.
+			if ($parts[0] != "") {
+				$output .= $parts[0];
+			}
+			
+			# Check if we reach the end.
+			if (isset($parts[1])) {
+				$output .= $this->handleSpanToken($parts[1], $parts[2]);
+				$str = $parts[2];
+			}
+			else {
+				break;
+			}
+		}
+		
+		return $output;
+	}
+	
+	
+	protected function handleSpanToken($token, &$str) {
+	#
+	# Handle $token provided by parseSpan by determining its nature and 
+	# returning the corresponding value that should replace it.
+	#
+		switch ($token{0}) {
+			case "\\":
+				return $this->hashPart("&#". ord($token{1}). ";");
+			case "`":
+				# Search for end marker in remaining text.
+				if (preg_match('/^(.*?[^`])'.preg_quote($token).'(?!`)(.*)$/sm', 
+					$str, $matches))
+				{
+					$str = $matches[2];
+					$codespan = $this->makeCodeSpan($matches[1]);
+					return $this->hashPart($codespan);
+				}
+				return $token; // return as text since no ending marker found.
+			default:
+				return $this->hashPart($token);
+		}
+	}
+
+
+	protected function outdent($text) {
+	#
+	# Remove one level of line-leading tabs or spaces
+	#
+		return preg_replace('/^(\t|[ ]{1,'.$this->tab_width.'})/m', '', $text);
+	}
+
+
+	# String length function for detab. `_initDetab` will create a function to 
+	# hanlde UTF-8 if the default function does not exist.
+	protected $utf8_strlen = 'mb_strlen';
+	
+	protected function detab($text) {
+	#
+	# Replace tabs with the appropriate amount of space.
+	#
+		# For each line we separate the line in blocks delemited by
+		# tab characters. Then we reconstruct every line by adding the 
+		# appropriate number of space between each blocks.
+		
+		$text = preg_replace_callback('/^.*\t.*$/m',
+			array($this, '_detab_callback'), $text);
+
+		return $text;
+	}
+	protected function _detab_callback($matches) {
+		$line = $matches[0];
+		$strlen = $this->utf8_strlen; # strlen function for UTF-8.
+		
+		# Split in blocks.
+		$blocks = explode("\t", $line);
+		# Add each blocks to the line.
+		$line = $blocks[0];
+		unset($blocks[0]); # Do not add first block twice.
+		foreach ($blocks as $block) {
+			# Calculate amount of space, insert spaces, insert block.
+			$amount = $this->tab_width - 
+				$strlen($line, 'UTF-8') % $this->tab_width;
+			$line .= str_repeat(" ", $amount) . $block;
+		}
+		return $line;
+	}
+	protected function _initDetab() {
+	#
+	# Check for the availability of the function in the `utf8_strlen` property
+	# (initially `mb_strlen`). If the function is not available, create a 
+	# function that will loosely count the number of UTF-8 characters with a
+	# regular expression.
+	#
+		if (function_exists($this->utf8_strlen)) return;
+		$this->utf8_strlen = create_function('$text', 'return preg_match_all(
+			"/[\\\\x00-\\\\xBF]|[\\\\xC0-\\\\xFF][\\\\x80-\\\\xBF]*/", 
+			$text, $m);');
+	}
+
+
+	protected function unhash($text) {
+	#
+	# Swap back in all the tags hashed by _HashHTMLBlocks.
+	#
+		return preg_replace_callback('/(.)\x1A[0-9]+\1/', 
+			array($this, '_unhash_callback'), $text);
+	}
+	protected function _unhash_callback($matches) {
+		return $this->html_hashes[$matches[0]];
+	}
+
+}
+
+
+#
+# Temporary Markdown Extra Parser Implementation Class
+#
+# NOTE: DON'T USE THIS CLASS
+# Currently the implementation of of Extra resides here in this temporary class.
+# This makes it easier to propagate the changes between the three different
+# packaging styles of PHP Markdown. When this issue is resolved, this
+# MarkdownExtra_TmpImpl class here will disappear and \Michelf\MarkdownExtra
+# will contain the code. So please use \Michelf\MarkdownExtra and ignore this
+# one.
+#
+
+abstract class _MarkdownExtra_TmpImpl extends \Michelf\Markdown {
+
+	### Configuration Variables ###
+
+	# Prefix for footnote ids.
+	public $fn_id_prefix = "";
+	
+	# Optional title attribute for footnote links and backlinks.
+	public $fn_link_title = "";
+	public $fn_backlink_title = "";
+	
+	# Optional class attribute for footnote links and backlinks.
+	public $fn_link_class = "footnote-ref";
+	public $fn_backlink_class = "footnote-backref";
+
+	# Class name for table cell alignment (%% replaced left/center/right)
+	# For instance: 'go-%%' becomes 'go-left' or 'go-right' or 'go-center'
+	# If empty, the align attribute is used instead of a class name.
+	public $table_align_class_tmpl = '';
+
+	# Optional class prefix for fenced code block.
+	public $code_class_prefix = "";
+	# Class attribute for code blocks goes on the `code` tag;
+	# setting this to true will put attributes on the `pre` tag instead.
+	public $code_attr_on_pre = false;
+	
+	# Predefined abbreviations.
+	public $predef_abbr = array();
+
+
+	### Parser Implementation ###
+
+	public function __construct() {
+	#
+	# Constructor function. Initialize the parser object.
+	#
+		# Add extra escapable characters before parent constructor 
+		# initialize the table.
+		$this->escape_chars .= ':|';
+		
+		# Insert extra document, block, and span transformations. 
+		# Parent constructor will do the sorting.
+		$this->document_gamut += array(
+			"doFencedCodeBlocks" => 5,
+			"stripFootnotes"     => 15,
+			"stripAbbreviations" => 25,
+			"appendFootnotes"    => 50,
+			);
+		$this->block_gamut += array(
+			"doFencedCodeBlocks" => 5,
+			"doTables"           => 15,
+			"doDefLists"         => 45,
+			);
+		$this->span_gamut += array(
+			"doFootnotes"        => 5,
+			"doAbbreviations"    => 70,
+			);
+		
+		parent::__construct();
+	}
+	
+	
+	# Extra variables used during extra transformations.
+	protected $footnotes = array();
+	protected $footnotes_ordered = array();
+	protected $footnotes_ref_count = array();
+	protected $footnotes_numbers = array();
+	protected $abbr_desciptions = array();
+	protected $abbr_word_re = '';
+	
+	# Give the current footnote number.
+	protected $footnote_counter = 1;
+	
+	
+	protected function setup() {
+	#
+	# Setting up Extra-specific variables.
+	#
+		parent::setup();
+		
+		$this->footnotes = array();
+		$this->footnotes_ordered = array();
+		$this->footnotes_ref_count = array();
+		$this->footnotes_numbers = array();
+		$this->abbr_desciptions = array();
+		$this->abbr_word_re = '';
+		$this->footnote_counter = 1;
+		
+		foreach ($this->predef_abbr as $abbr_word => $abbr_desc) {
+			if ($this->abbr_word_re)
+				$this->abbr_word_re .= '|';
+			$this->abbr_word_re .= preg_quote($abbr_word);
+			$this->abbr_desciptions[$abbr_word] = trim($abbr_desc);
+		}
+	}
+	
+	protected function teardown() {
+	#
+	# Clearing Extra-specific variables.
+	#
+		$this->footnotes = array();
+		$this->footnotes_ordered = array();
+		$this->footnotes_ref_count = array();
+		$this->footnotes_numbers = array();
+		$this->abbr_desciptions = array();
+		$this->abbr_word_re = '';
+		
+		parent::teardown();
+	}
+	
+	
+	### Extra Attribute Parser ###
+
+	# Expression to use to catch attributes (includes the braces)
+	protected $id_class_attr_catch_re = '\{((?:[ ]*[#.a-z][-_:a-zA-Z0-9=]+){1,})[ ]*\}';
+	# Expression to use when parsing in a context when no capture is desired
+	protected $id_class_attr_nocatch_re = '\{(?:[ ]*[#.a-z][-_:a-zA-Z0-9=]+){1,}[ ]*\}';
+
+	protected function doExtraAttributes($tag_name, $attr) {
+	#
+	# Parse attributes caught by the $this->id_class_attr_catch_re expression
+	# and return the HTML-formatted list of attributes.
+	#
+	# Currently supported attributes are .class and #id.
+	#
+		if (empty($attr)) return "";
+		
+		# Split on components
+		preg_match_all('/[#.a-z][-_:a-zA-Z0-9=]+/', $attr, $matches);
+		$elements = $matches[0];
+
+		# handle classes and ids (only first id taken into account)
+		$classes = array();
+		$attributes = array();
+		$id = false;
+		foreach ($elements as $element) {
+			if ($element{0} == '.') {
+				$classes[] = substr($element, 1);
+			} else if ($element{0} == '#') {
+				if ($id === false) $id = substr($element, 1);
+			} else if (strpos($element, '=') > 0) {
+				$parts = explode('=', $element, 2);
+				$attributes[] = $parts[0] . '="' . $parts[1] . '"';
+			}
+		}
+
+		# compose attributes as string
+		$attr_str = "";
+		if (!empty($id)) {
+			$attr_str .= ' id="'.$id.'"';
+		}
+		if (!empty($classes)) {
+			$attr_str .= ' class="'.implode(" ", $classes).'"';
+		}
+		if (!$this->no_markup && !empty($attributes)) {
+			$attr_str .= ' '.implode(" ", $attributes);
+		}
+		return $attr_str;
+	}
+
+
+	protected function stripLinkDefinitions($text) {
+	#
+	# Strips link definitions from text, stores the URLs and titles in
+	# hash references.
+	#
+		$less_than_tab = $this->tab_width - 1;
+
+		# Link defs are in the form: ^[id]: url "optional title"
+		$text = preg_replace_callback('{
+							^[ ]{0,'.$less_than_tab.'}\[(.+)\][ ]?:	# id = $1
+							  [ ]*
+							  \n?				# maybe *one* newline
+							  [ ]*
+							(?:
+							  <(.+?)>			# url = $2
+							|
+							  (\S+?)			# url = $3
+							)
+							  [ ]*
+							  \n?				# maybe one newline
+							  [ ]*
+							(?:
+								(?<=\s)			# lookbehind for whitespace
+								["(]
+								(.*?)			# title = $4
+								[")]
+								[ ]*
+							)?	# title is optional
+					(?:[ ]* '.$this->id_class_attr_catch_re.' )?  # $5 = extra id & class attr
+							(?:\n+|\Z)
+			}xm',
+			array($this, '_stripLinkDefinitions_callback'),
+			$text);
+		return $text;
+	}
+	protected function _stripLinkDefinitions_callback($matches) {
+		$link_id = strtolower($matches[1]);
+		$url = $matches[2] == '' ? $matches[3] : $matches[2];
+		$this->urls[$link_id] = $url;
+		$this->titles[$link_id] =& $matches[4];
+		$this->ref_attr[$link_id] = $this->doExtraAttributes("", $dummy =& $matches[5]);
+		return ''; # String that will replace the block
+	}
+
+
+	### HTML Block Parser ###
+	
+	# Tags that are always treated as block tags:
+	protected $block_tags_re = 'p|div|h[1-6]|blockquote|pre|table|dl|ol|ul|address|form|fieldset|iframe|hr|legend|article|section|nav|aside|hgroup|header|footer|figcaption|figure';
+						   
+	# Tags treated as block tags only if the opening tag is alone on its line:
+	protected $context_block_tags_re = 'script|noscript|style|ins|del|iframe|object|source|track|param|math|svg|canvas|audio|video';
+	
+	# Tags where markdown="1" default to span mode:
+	protected $contain_span_tags_re = 'p|h[1-6]|li|dd|dt|td|th|legend|address';
+	
+	# Tags which must not have their contents modified, no matter where 
+	# they appear:
+	protected $clean_tags_re = 'script|style|math|svg';
+	
+	# Tags that do not need to be closed.
+	protected $auto_close_tags_re = 'hr|img|param|source|track';
+	
+
+	protected function hashHTMLBlocks($text) {
+	#
+	# Hashify HTML Blocks and "clean tags".
+	#
+	# We only want to do this for block-level HTML tags, such as headers,
+	# lists, and tables. That's because we still want to wrap 
    s around
+	# "paragraphs" that are wrapped in non-block-level tags, such as anchors,
+	# phrase emphasis, and spans. The list of tags we're looking for is
+	# hard-coded.
+	#
+	# This works by calling _HashHTMLBlocks_InMarkdown, which then calls
+	# _HashHTMLBlocks_InHTML when it encounter block tags. When the markdown="1" 
+	# attribute is found within a tag, _HashHTMLBlocks_InHTML calls back
+	#  _HashHTMLBlocks_InMarkdown to handle the Markdown syntax within the tag.
+	# These two functions are calling each other. It's recursive!
+	#
+		if ($this->no_markup)  return $text;
+
+		#
+		# Call the HTML-in-Markdown hasher.
+		#
+		list($text, ) = $this->_hashHTMLBlocks_inMarkdown($text);
+		
+		return $text;
+	}
+	protected function _hashHTMLBlocks_inMarkdown($text, $indent = 0,
+										$enclosing_tag_re = '', $span = false)
+	{
+	#
+	# Parse markdown text, calling _HashHTMLBlocks_InHTML for block tags.
+	#
+	# *   $indent is the number of space to be ignored when checking for code 
+	#     blocks. This is important because if we don't take the indent into 
+	#     account, something like this (which looks right) won't work as expected:
+	#
+	#     
    
+	#         
    
+	#         Hello World.  <-- Is this a Markdown code block or text?
+	#         
      <-- Is this a Markdown code block or a real tag?
+	#     
    
+	#
+	#     If you don't like this, just don't indent the tag on which
+	#     you apply the markdown="1" attribute.
+	#
+	# *   If $enclosing_tag_re is not empty, stops at the first unmatched closing 
+	#     tag with that name. Nested tags supported.
+	#
+	# *   If $span is true, text inside must treated as span. So any double 
+	#     newline will be replaced by a single newline so that it does not create 
+	#     paragraphs.
+	#
+	# Returns an array of that form: ( processed text , remaining text )
+	#
+		if ($text === '') return array('', '');
+
+		# Regex to check for the presense of newlines around a block tag.
+		$newline_before_re = '/(?:^\n?|\n\n)*$/';
+		$newline_after_re = 
+			'{
+				^						# Start of text following the tag.
+				(?>[ ]*)?		# Optional comment.
+				[ ]*\n					# Must be followed by newline.
+			}xs';
+		
+		# Regex to match any tag.
+		$block_tag_re =
+			'{
+				(					# $2: Capture whole tag.
+									# Tag name.
+							'.$this->block_tags_re.'			|
+							'.$this->context_block_tags_re.'	|
+							'.$this->clean_tags_re.'        	|
+							(?!\s)'.$enclosing_tag_re.'
+						)
+						(?:
+							(?=[\s"\'/a-zA-Z0-9])	# Allowed characters after tag name.
+							(?>
+								".*?"		|	# Double quotes (can contain `>`)
+								\'.*?\'   	|	# Single quotes (can contain `>`)
+								.+?				# Anything but quotes and `>`.
+							)*?
+						)?
+					>					# End of tag.
+				|
+						# HTML Comment
+				|
+					<\?.*?\?> | <%.*?%>	# Processing instruction
+				|
+						# CData Block
+				'. ( !$span ? ' # If not in span.
+				|
+					# Indented code block
+					(?: ^[ ]*\n | ^ | \n[ ]*\n )
+					[ ]{'.($indent+4).'}[^\n]* \n
+					(?>
+						(?: [ ]{'.($indent+4).'}[^\n]* | [ ]* ) \n
+					)*
+				|
+					# Fenced code block marker
+					(?<= ^ | \n )
+					[ ]{0,'.($indent+3).'}(?:~{3,}|`{3,})
+									[ ]*
+					(?:
+					\.?[-_:a-zA-Z0-9]+ # standalone class name
+					|
+						'.$this->id_class_attr_nocatch_re.' # extra attributes
+					)?
+					[ ]*
+					(?= \n )
+				' : '' ). ' # End (if not is span).
+				|
+					# Code span marker
+					# Note, this regex needs to go after backtick fenced
+					# code blocks but it should also be kept outside of the
+					# "if not in span" condition adding backticks to the parser
+					`+
+				)
+			}xs';
+
+		
+		$depth = 0;		# Current depth inside the tag tree.
+		$parsed = "";	# Parsed text that will be returned.
+
+		#
+		# Loop through every tag until we find the closing tag of the parent
+		# or loop until reaching the end of text if no parent tag specified.
+		#
+		do {
+			#
+			# Split the text using the first $tag_match pattern found.
+			# Text before  pattern will be first in the array, text after
+			# pattern will be at the end, and between will be any catches made 
+			# by the pattern.
+			#
+			$parts = preg_split($block_tag_re, $text, 2, 
+								PREG_SPLIT_DELIM_CAPTURE);
+			
+			# If in Markdown span mode, add a empty-string span-level hash 
+			# after each newline to prevent triggering any block element.
+			if ($span) {
+				$void = $this->hashPart("", ':');
+				$newline = "$void\n";
+				$parts[0] = $void . str_replace("\n", $newline, $parts[0]) . $void;
+			}
+			
+			$parsed .= $parts[0]; # Text before current tag.
+			
+			# If end of $text has been reached. Stop loop.
+			if (count($parts) < 3) {
+				$text = "";
+				break;
+			}
+			
+			$tag  = $parts[1]; # Tag to handle.
+			$text = $parts[2]; # Remaining text after current tag.
+			$tag_re = preg_quote($tag); # For use in a regular expression.
+			
+			#
+			# Check for: Fenced code block marker.
+			# Note: need to recheck the whole tag to disambiguate backtick
+			# fences from code spans
+			#
+			if (preg_match('{^\n?([ ]{0,'.($indent+3).'})(~{3,}|`{3,})[ ]*(?:\.?[-_:a-zA-Z0-9]+|'.$this->id_class_attr_nocatch_re.')?[ ]*\n?$}', $tag, $capture)) {
+				# Fenced code block marker: find matching end marker.
+				$fence_indent = strlen($capture[1]); # use captured indent in re
+				$fence_re = $capture[2]; # use captured fence in re
+				if (preg_match('{^(?>.*\n)*?[ ]{'.($fence_indent).'}'.$fence_re.'[ ]*(?:\n|$)}', $text,
+					$matches)) 
+				{
+					# End marker found: pass text unchanged until marker.
+					$parsed .= $tag . $matches[0];
+					$text = substr($text, strlen($matches[0]));
+				}
+				else {
+					# No end marker: just skip it.
+					$parsed .= $tag;
+				}
+			}
+			#
+			# Check for: Indented code block.
+			#
+			else if ($tag{0} == "\n" || $tag{0} == " ") {
+				# Indented code block: pass it unchanged, will be handled 
+				# later.
+				$parsed .= $tag;
+			}
+			#
+			# Check for: Code span marker
+			# Note: need to check this after backtick fenced code blocks
+			#
+			else if ($tag{0} == "`") {
+				# Find corresponding end marker.
+				$tag_re = preg_quote($tag);
+				if (preg_match('{^(?>.+?|\n(?!\n))*?(?block_tags_re.')\b}', $tag) ||
+				(	preg_match('{^<(?:'.$this->context_block_tags_re.')\b}', $tag) &&
+					preg_match($newline_before_re, $parsed) &&
+					preg_match($newline_after_re, $text)	)
+				)
+			{
+				# Need to parse tag and following text using the HTML parser.
+				list($block_text, $text) = 
+					$this->_hashHTMLBlocks_inHTML($tag . $text, "hashBlock", true);
+				
+				# Make sure it stays outside of any paragraph by adding newlines.
+				$parsed .= "\n\n$block_text\n\n";
+			}
+			#
+			# Check for: Clean tag (like script, math)
+			#            HTML Comments, processing instructions.
+			#
+			else if (preg_match('{^<(?:'.$this->clean_tags_re.')\b}', $tag) ||
+				$tag{1} == '!' || $tag{1} == '?')
+			{
+				# Need to parse tag and following text using the HTML parser.
+				# (don't check for markdown attribute)
+				list($block_text, $text) = 
+					$this->_hashHTMLBlocks_inHTML($tag . $text, "hashClean", false);
+				
+				$parsed .= $block_text;
+			}
+			#
+			# Check for: Tag with same name as enclosing tag.
+			#
+			else if ($enclosing_tag_re !== '' &&
+				# Same name as enclosing tag.
+				preg_match('{^= 0);
+		
+		return array($parsed, $text);
+	}
+	protected function _hashHTMLBlocks_inHTML($text, $hash_method, $md_attr) {
+	#
+	# Parse HTML, calling _HashHTMLBlocks_InMarkdown for block tags.
+	#
+	# *   Calls $hash_method to convert any blocks.
+	# *   Stops when the first opening tag closes.
+	# *   $md_attr indicate if the use of the `markdown="1"` attribute is allowed.
+	#     (it is not inside clean tags)
+	#
+	# Returns an array of that form: ( processed text , remaining text )
+	#
+		if ($text === '') return array('', '');
+		
+		# Regex to match `markdown` attribute inside of a tag.
+		$markdown_attr_re = '
+			{
+				\s*			# Eat whitespace before the `markdown` attribute
+				markdown
+				\s*=\s*
+				(?>
+					(["\'])		# $1: quote delimiter		
+					(.*?)		# $2: attribute value
+					\1			# matching delimiter	
+				|
+					([^\s>]*)	# $3: unquoted attribute value
+				)
+				()				# $4: make $3 always defined (avoid warnings)
+			}xs';
+		
+		# Regex to match any tag.
+		$tag_re = '{
+				(					# $2: Capture whole tag.
+					
+								".*?"		|	# Double quotes (can contain `>`)
+								\'.*?\'   	|	# Single quotes (can contain `>`)
+								.+?				# Anything but quotes and `>`.
+							)*?
+						)?
+					>					# End of tag.
+				|
+						# HTML Comment
+				|
+					<\?.*?\?> | <%.*?%>	# Processing instruction
+				|
+						# CData Block
+				)
+			}xs';
+		
+		$original_text = $text;		# Save original text in case of faliure.
+		
+		$depth		= 0;	# Current depth inside the tag tree.
+		$block_text	= "";	# Temporary text holder for current text.
+		$parsed		= "";	# Parsed text that will be returned.
+
+		#
+		# Get the name of the starting tag.
+		# (This pattern makes $base_tag_name_re safe without quoting.)
+		#
+		if (preg_match('/^<([\w:$]*)\b/', $text, $matches))
+			$base_tag_name_re = $matches[1];
+
+		#
+		# Loop through every tag until we find the corresponding closing tag.
+		#
+		do {
+			#
+			# Split the text using the first $tag_match pattern found.
+			# Text before  pattern will be first in the array, text after
+			# pattern will be at the end, and between will be any catches made 
+			# by the pattern.
+			#
+			$parts = preg_split($tag_re, $text, 2, PREG_SPLIT_DELIM_CAPTURE);
+			
+			if (count($parts) < 3) {
+				#
+				# End of $text reached with unbalenced tag(s).
+				# In that case, we return original text unchanged and pass the
+				# first character as filtered to prevent an infinite loop in the 
+				# parent function.
+				#
+				return array($original_text{0}, substr($original_text, 1));
+			}
+			
+			$block_text .= $parts[0]; # Text before current tag.
+			$tag         = $parts[1]; # Tag to handle.
+			$text        = $parts[2]; # Remaining text after current tag.
+			
+			#
+			# Check for: Auto-close tag (like 
    )
+			#			 Comments and Processing Instructions.
+			#
+			if (preg_match('{^auto_close_tags_re.')\b}', $tag) ||
+				$tag{1} == '!' || $tag{1} == '?')
+			{
+				# Just add the tag to the block as if it was text.
+				$block_text .= $tag;
+			}
+			else {
+				#
+				# Increase/decrease nested tag count. Only do so if
+				# the tag's name match base tag's.
+				#
+				if (preg_match('{^mode = $attr_m[2] . $attr_m[3];
+					$span_mode = $this->mode == 'span' || $this->mode != 'block' &&
+						preg_match('{^<(?:'.$this->contain_span_tags_re.')\b}', $tag);
+					
+					# Calculate indent before tag.
+					if (preg_match('/(?:^|\n)( *?)(?! ).*?$/', $block_text, $matches)) {
+						$strlen = $this->utf8_strlen;
+						$indent = $strlen($matches[1], 'UTF-8');
+					} else {
+						$indent = 0;
+					}
+					
+					# End preceding block with this tag.
+					$block_text .= $tag;
+					$parsed .= $this->$hash_method($block_text);
+					
+					# Get enclosing tag name for the ParseMarkdown function.
+					# (This pattern makes $tag_name_re safe without quoting.)
+					preg_match('/^<([\w:$]*)\b/', $tag, $matches);
+					$tag_name_re = $matches[1];
+					
+					# Parse the content using the HTML-in-Markdown parser.
+					list ($block_text, $text)
+						= $this->_hashHTMLBlocks_inMarkdown($text, $indent, 
+							$tag_name_re, $span_mode);
+					
+					# Outdent markdown text.
+					if ($indent > 0) {
+						$block_text = preg_replace("/^[ ]{1,$indent}/m", "", 
+													$block_text);
+					}
+					
+					# Append tag content to parsed text.
+					if (!$span_mode)	$parsed .= "\n\n$block_text\n\n";
+					else				$parsed .= "$block_text";
+					
+					# Start over with a new block.
+					$block_text = "";
+				}
+				else $block_text .= $tag;
+			}
+			
+		} while ($depth > 0);
+		
+		#
+		# Hash last block text that wasn't processed inside the loop.
+		#
+		$parsed .= $this->$hash_method($block_text);
+		
+		return array($parsed, $text);
+	}
+
+
+	protected function hashClean($text) {
+	#
+	# Called whenever a tag must be hashed when a function inserts a "clean" tag
+	# in $text, it passes through this function and is automaticaly escaped, 
+	# blocking invalid nested overlap.
+	#
+		return $this->hashPart($text, 'C');
+	}
+
+
+	protected function doAnchors($text) {
+	#
+	# Turn Markdown link shortcuts into XHTML  tags.
+	#
+		if ($this->in_anchor) return $text;
+		$this->in_anchor = true;
+		
+		#
+		# First, handle reference-style links: [link text] [id]
+		#
+		$text = preg_replace_callback('{
+			(					# wrap whole match in $1
+			  \[
+				('.$this->nested_brackets_re.')	# link text = $2
+			  \]
+
+			  [ ]?				# one optional space
+			  (?:\n[ ]*)?		# one optional newline followed by spaces
+
+			  \[
+				(.*?)		# id = $3
+			  \]
+			)
+			}xs',
+			array($this, '_doAnchors_reference_callback'), $text);
+
+		#
+		# Next, inline-style links: [link text](url "optional title")
+		#
+		$text = preg_replace_callback('{
+			(				# wrap whole match in $1
+			  \[
+				('.$this->nested_brackets_re.')	# link text = $2
+			  \]
+			  \(			# literal paren
+				[ \n]*
+				(?:
+					<(.+?)>	# href = $3
+				|
+					('.$this->nested_url_parenthesis_re.')	# href = $4
+				)
+				[ \n]*
+				(			# $5
+				  ([\'"])	# quote char = $6
+				  (.*?)		# Title = $7
+				  \6		# matching quote
+				  [ \n]*	# ignore any spaces/tabs between closing quote and )
+				)?			# title is optional
+			  \)
+			  (?:[ ]? '.$this->id_class_attr_catch_re.' )?	 # $8 = id/class attributes
+			)
+			}xs',
+			array($this, '_doAnchors_inline_callback'), $text);
+
+		#
+		# Last, handle reference-style shortcuts: [link text]
+		# These must come last in case you've also got [link text][1]
+		# or [link text](/foo)
+		#
+		$text = preg_replace_callback('{
+			(					# wrap whole match in $1
+			  \[
+				([^\[\]]+)		# link text = $2; can\'t contain [ or ]
+			  \]
+			)
+			}xs',
+			array($this, '_doAnchors_reference_callback'), $text);
+
+		$this->in_anchor = false;
+		return $text;
+	}
+	protected function _doAnchors_reference_callback($matches) {
+		$whole_match =  $matches[1];
+		$link_text   =  $matches[2];
+		$link_id     =& $matches[3];
+
+		if ($link_id == "") {
+			# for shortcut links like [this][] or [this].
+			$link_id = $link_text;
+		}
+		
+		# lower-case and turn embedded newlines into spaces
+		$link_id = strtolower($link_id);
+		$link_id = preg_replace('{[ ]?\n}', ' ', $link_id);
+
+		if (isset($this->urls[$link_id])) {
+			$url = $this->urls[$link_id];
+			$url = $this->encodeURLAttribute($url);
+			
+			$result = "titles[$link_id] ) ) {
+				$title = $this->titles[$link_id];
+				$title = $this->encodeAttribute($title);
+				$result .=  " title=\"$title\"";
+			}
+			if (isset($this->ref_attr[$link_id]))
+				$result .= $this->ref_attr[$link_id];
+		
+			$link_text = $this->runSpanGamut($link_text);
+			$result .= ">$link_text";
+			$result = $this->hashPart($result);
+		}
+		else {
+			$result = $whole_match;
+		}
+		return $result;
+	}
+	protected function _doAnchors_inline_callback($matches) {
+		$whole_match	=  $matches[1];
+		$link_text		=  $this->runSpanGamut($matches[2]);
+		$url			=  $matches[3] == '' ? $matches[4] : $matches[3];
+		$title			=& $matches[7];
+		$attr  = $this->doExtraAttributes("a", $dummy =& $matches[8]);
+
+		// if the URL was of the form  it got caught by the HTML
+		// tag parser and hashed. Need to reverse the process before using the URL.
+		$unhashed = $this->unhash($url);
+		if ($unhashed != $url)
+			$url = preg_replace('/^<(.*)>$/', '\1', $unhashed);
+
+		$url = $this->encodeURLAttribute($url);
+
+		$result = "encodeAttribute($title);
+			$result .=  " title=\"$title\"";
+		}
+		$result .= $attr;
+		
+		$link_text = $this->runSpanGamut($link_text);
+		$result .= ">$link_text";
+
+		return $this->hashPart($result);
+	}
+
+
+	protected function doImages($text) {
+	#
+	# Turn Markdown image shortcuts into  tags.
+	#
+		#
+		# First, handle reference-style labeled images: ![alt text][id]
+		#
+		$text = preg_replace_callback('{
+			(				# wrap whole match in $1
+			  !\[
+				('.$this->nested_brackets_re.')		# alt text = $2
+			  \]
+
+			  [ ]?				# one optional space
+			  (?:\n[ ]*)?		# one optional newline followed by spaces
+
+			  \[
+				(.*?)		# id = $3
+			  \]
+
+			)
+			}xs', 
+			array($this, '_doImages_reference_callback'), $text);
+
+		#
+		# Next, handle inline images:  ![alt text](url "optional title")
+		# Don't forget: encode * and _
+		#
+		$text = preg_replace_callback('{
+			(				# wrap whole match in $1
+			  !\[
+				('.$this->nested_brackets_re.')		# alt text = $2
+			  \]
+			  \s?			# One optional whitespace character
+			  \(			# literal paren
+				[ \n]*
+				(?:
+					<(\S*)>	# src url = $3
+				|
+					('.$this->nested_url_parenthesis_re.')	# src url = $4
+				)
+				[ \n]*
+				(			# $5
+				  ([\'"])	# quote char = $6
+				  (.*?)		# title = $7
+				  \6		# matching quote
+				  [ \n]*
+				)?			# title is optional
+			  \)
+			  (?:[ ]? '.$this->id_class_attr_catch_re.' )?	 # $8 = id/class attributes
+			)
+			}xs',
+			array($this, '_doImages_inline_callback'), $text);
+
+		return $text;
+	}
+	protected function _doImages_reference_callback($matches) {
+		$whole_match = $matches[1];
+		$alt_text    = $matches[2];
+		$link_id     = strtolower($matches[3]);
+
+		if ($link_id == "") {
+			$link_id = strtolower($alt_text); # for shortcut links like ![this][].
+		}
+
+		$alt_text = $this->encodeAttribute($alt_text);
+		if (isset($this->urls[$link_id])) {
+			$url = $this->encodeURLAttribute($this->urls[$link_id]);
+			$result = "\"$alt_text\"";titles[$link_id])) {
+				$title = $this->titles[$link_id];
+				$title = $this->encodeAttribute($title);
+				$result .=  " title=\"$title\"";
+			}
+			if (isset($this->ref_attr[$link_id]))
+				$result .= $this->ref_attr[$link_id];
+			$result .= $this->empty_element_suffix;
+			$result = $this->hashPart($result);
+		}
+		else {
+			# If there's no such link ID, leave intact:
+			$result = $whole_match;
+		}
+
+		return $result;
+	}
+	protected function _doImages_inline_callback($matches) {
+		$whole_match	= $matches[1];
+		$alt_text		= $matches[2];
+		$url			= $matches[3] == '' ? $matches[4] : $matches[3];
+		$title			=& $matches[7];
+		$attr  = $this->doExtraAttributes("img", $dummy =& $matches[8]);
+
+		$alt_text = $this->encodeAttribute($alt_text);
+		$url = $this->encodeURLAttribute($url);
+		$result = "\"$alt_text\"";encodeAttribute($title);
+			$result .=  " title=\"$title\""; # $title already quoted
+		}
+		$result .= $attr;
+		$result .= $this->empty_element_suffix;
+
+		return $this->hashPart($result);
+	}
+
+
+	protected function doHeaders($text) {
+	#
+	# Redefined to add id and class attribute support.
+	#
+		# Setext-style headers:
+		#	  Header 1  {#header1}
+		#	  ========
+		#  
+		#	  Header 2  {#header2 .class1 .class2}
+		#	  --------
+		#
+		$text = preg_replace_callback(
+			'{
+				(^.+?)								# $1: Header text
+				(?:[ ]+ '.$this->id_class_attr_catch_re.' )?	 # $3 = id/class attributes
+				[ ]*\n(=+|-+)[ ]*\n+				# $3: Header footer
+			}mx',
+			array($this, '_doHeaders_callback_setext'), $text);
+
+		# atx-style headers:
+		#	# Header 1        {#header1}
+		#	## Header 2       {#header2}
+		#	## Header 2 with closing hashes ##  {#header3.class1.class2}
+		#	...
+		#	###### Header 6   {.class2}
+		#
+		$text = preg_replace_callback('{
+				^(\#{1,6})	# $1 = string of #\'s
+				[ ]*
+				(.+?)		# $2 = Header text
+				[ ]*
+				\#*			# optional closing #\'s (not counted)
+				(?:[ ]+ '.$this->id_class_attr_catch_re.' )?	 # $3 = id/class attributes
+				[ ]*
+				\n+
+			}xm',
+			array($this, '_doHeaders_callback_atx'), $text);
+
+		return $text;
+	}
+	protected function _doHeaders_callback_setext($matches) {
+		if ($matches[3] == '-' && preg_match('{^- }', $matches[1]))
+			return $matches[0];
+		$level = $matches[3]{0} == '=' ? 1 : 2;
+		$attr  = $this->doExtraAttributes("h$level", $dummy =& $matches[2]);
+		$block = "".$this->runSpanGamut($matches[1])."";
+		return "\n" . $this->hashBlock($block) . "\n\n";
+	}
+	protected function _doHeaders_callback_atx($matches) {
+		$level = strlen($matches[1]);
+		$attr  = $this->doExtraAttributes("h$level", $dummy =& $matches[3]);
+		$block = "".$this->runSpanGamut($matches[2])."";
+		return "\n" . $this->hashBlock($block) . "\n\n";
+	}
+
+
+	protected function doTables($text) {
+	#
+	# Form HTML tables.
+	#
+		$less_than_tab = $this->tab_width - 1;
+		#
+		# Find tables with leading pipe.
+		#
+		#	| Header 1 | Header 2
+		#	| -------- | --------
+		#	| Cell 1   | Cell 2
+		#	| Cell 3   | Cell 4
+		#
+		$text = preg_replace_callback('
+			{
+				^							# Start of a line
+				[ ]{0,'.$less_than_tab.'}	# Allowed whitespace.
+				[|]							# Optional leading pipe (present)
+				(.+) \n						# $1: Header row (at least one pipe)
+				
+				[ ]{0,'.$less_than_tab.'}	# Allowed whitespace.
+				[|] ([ ]*[-:]+[-| :]*) \n	# $2: Header underline
+				
+				(							# $3: Cells
+					(?>
+						[ ]*				# Allowed whitespace.
+						[|] .* \n			# Row content.
+					)*
+				)
+				(?=\n|\Z)					# Stop at final double newline.
+			}xm',
+			array($this, '_doTable_leadingPipe_callback'), $text);
+		
+		#
+		# Find tables without leading pipe.
+		#
+		#	Header 1 | Header 2
+		#	-------- | --------
+		#	Cell 1   | Cell 2
+		#	Cell 3   | Cell 4
+		#
+		$text = preg_replace_callback('
+			{
+				^							# Start of a line
+				[ ]{0,'.$less_than_tab.'}	# Allowed whitespace.
+				(\S.*[|].*) \n				# $1: Header row (at least one pipe)
+				
+				[ ]{0,'.$less_than_tab.'}	# Allowed whitespace.
+				([-:]+[ ]*[|][-| :]*) \n	# $2: Header underline
+				
+				(							# $3: Cells
+					(?>
+						.* [|] .* \n		# Row content
+					)*
+				)
+				(?=\n|\Z)					# Stop at final double newline.
+			}xm',
+			array($this, '_DoTable_callback'), $text);
+
+		return $text;
+	}
+	protected function _doTable_leadingPipe_callback($matches) {
+		$head		= $matches[1];
+		$underline	= $matches[2];
+		$content	= $matches[3];
+		
+		# Remove leading pipe for each row.
+		$content	= preg_replace('/^ *[|]/m', '', $content);
+		
+		return $this->_doTable_callback(array($matches[0], $head, $underline, $content));
+	}
+	protected function _doTable_makeAlignAttr($alignname)
+	{
+		if (empty($this->table_align_class_tmpl))
+			return " align=\"$alignname\"";
+
+		$classname = str_replace('%%', $alignname, $this->table_align_class_tmpl);
+		return " class=\"$classname\"";
+	}
+	protected function _doTable_callback($matches) {
+		$head		= $matches[1];
+		$underline	= $matches[2];
+		$content	= $matches[3];
+
+		# Remove any tailing pipes for each line.
+		$head		= preg_replace('/[|] *$/m', '', $head);
+		$underline	= preg_replace('/[|] *$/m', '', $underline);
+		$content	= preg_replace('/[|] *$/m', '', $content);
+		
+		# Reading alignement from header underline.
+		$separators	= preg_split('/ *[|] */', $underline);
+		foreach ($separators as $n => $s) {
+			if (preg_match('/^ *-+: *$/', $s))
+				$attr[$n] = $this->_doTable_makeAlignAttr('right');
+			else if (preg_match('/^ *:-+: *$/', $s))
+				$attr[$n] = $this->_doTable_makeAlignAttr('center');
+			else if (preg_match('/^ *:-+ *$/', $s))
+				$attr[$n] = $this->_doTable_makeAlignAttr('left');
+			else
+				$attr[$n] = '';
+		}
+		
+		# Parsing span elements, including code spans, character escapes, 
+		# and inline HTML tags, so that pipes inside those gets ignored.
+		$head		= $this->parseSpan($head);
+		$headers	= preg_split('/ *[|] */', $head);
+		$col_count	= count($headers);
+		$attr       = array_pad($attr, $col_count, '');
+		
+		# Write column headers.
+		$text = "\n";
+		$text .= "\n";
+		$text .= "\n";
+		foreach ($headers as $n => $header)
+			$text .= "  ".$this->runSpanGamut(trim($header))."\n";
+		$text .= "\n";
+		$text .= "\n";
+		
+		# Split content by row.
+		$rows = explode("\n", trim($content, "\n"));
+		
+		$text .= "\n";
+		foreach ($rows as $row) {
+			# Parsing span elements, including code spans, character escapes, 
+			# and inline HTML tags, so that pipes inside those gets ignored.
+			$row = $this->parseSpan($row);
+			
+			# Split row by cell.
+			$row_cells = preg_split('/ *[|] */', $row, $col_count);
+			$row_cells = array_pad($row_cells, $col_count, '');
+			
+			$text .= "\n";
+			foreach ($row_cells as $n => $cell)
+				$text .= "  ".$this->runSpanGamut(trim($cell))."\n";
+			$text .= "\n";
+		}
+		$text .= "\n";
+		$text .= "
    ";
+		
+		return $this->hashBlock($text) . "\n";
+	}
+
+	
+	protected function doDefLists($text) {
+	#
+	# Form HTML definition lists.
+	#
+		$less_than_tab = $this->tab_width - 1;
+
+		# Re-usable pattern to match any entire dl list:
+		$whole_list_re = '(?>
+			(								# $1 = whole list
+			  (								# $2
+				[ ]{0,'.$less_than_tab.'}
+				((?>.*\S.*\n)+)				# $3 = defined term
+				\n?
+				[ ]{0,'.$less_than_tab.'}:[ ]+ # colon starting definition
+			  )
+			  (?s:.+?)
+			  (								# $4
+				  \z
+				|
+				  \n{2,}
+				  (?=\S)
+				  (?!						# Negative lookahead for another term
+					[ ]{0,'.$less_than_tab.'}
+					(?: \S.*\n )+?			# defined term
+					\n?
+					[ ]{0,'.$less_than_tab.'}:[ ]+ # colon starting definition
+				  )
+				  (?!						# Negative lookahead for another definition
+					[ ]{0,'.$less_than_tab.'}:[ ]+ # colon starting definition
+				  )
+			  )
+			)
+		)'; // mx
+
+		$text = preg_replace_callback('{
+				(?>\A\n?|(?<=\n\n))
+				'.$whole_list_re.'
+			}mx',
+			array($this, '_doDefLists_callback'), $text);
+
+		return $text;
+	}
+	protected function _doDefLists_callback($matches) {
+		# Re-usable patterns to match list item bullets and number markers:
+		$list = $matches[1];
+		
+		# Turn double returns into triple returns, so that we can make a
+		# paragraph for the last item in a list, if necessary:
+		$result = trim($this->processDefListItems($list));
+		$result = "
    \n" . $result . "\n
    ";
+		return $this->hashBlock($result) . "\n\n";
+	}
+
+
+	protected function processDefListItems($list_str) {
+	#
+	#	Process the contents of a single definition list, splitting it
+	#	into individual term and definition list items.
+	#
+		$less_than_tab = $this->tab_width - 1;
+		
+		# trim trailing blank lines:
+		$list_str = preg_replace("/\n{2,}\\z/", "\n", $list_str);
+
+		# Process definition terms.
+		$list_str = preg_replace_callback('{
+			(?>\A\n?|\n\n+)					# leading line
+			(								# definition terms = $1
+				[ ]{0,'.$less_than_tab.'}	# leading whitespace
+				(?!\:[ ]|[ ])				# negative lookahead for a definition
+											#   mark (colon) or more whitespace.
+				(?> \S.* \n)+?				# actual term (not whitespace).	
+			)			
+			(?=\n?[ ]{0,3}:[ ])				# lookahead for following line feed 
+											#   with a definition mark.
+			}xm',
+			array($this, '_processDefListItems_callback_dt'), $list_str);
+
+		# Process actual definitions.
+		$list_str = preg_replace_callback('{
+			\n(\n+)?						# leading line = $1
+			(								# marker space = $2
+				[ ]{0,'.$less_than_tab.'}	# whitespace before colon
+				\:[ ]+						# definition mark (colon)
+			)
+			((?s:.+?))						# definition text = $3
+			(?= \n+ 						# stop at next definition mark,
+				(?:							# next term or end of text
+					[ ]{0,'.$less_than_tab.'} \:[ ]	|
+					
     | \z
+				)						
+			)					
+			}xm',
+			array($this, '_processDefListItems_callback_dd'), $list_str);
+
+		return $list_str;
+	}
+	protected function _processDefListItems_callback_dt($matches) {
+		$terms = explode("\n", trim($matches[1]));
+		$text = '';
+		foreach ($terms as $term) {
+			$term = $this->runSpanGamut(trim($term));
+			$text .= "\n
    " . $term . "
    ";
+		}
+		return $text . "\n";
+	}
+	protected function _processDefListItems_callback_dd($matches) {
+		$leading_line	= $matches[1];
+		$marker_space	= $matches[2];
+		$def			= $matches[3];
+
+		if ($leading_line || preg_match('/\n{2,}/', $def)) {
+			# Replace marker with the appropriate whitespace indentation
+			$def = str_repeat(' ', strlen($marker_space)) . $def;
+			$def = $this->runBlockGamut($this->outdent($def . "\n\n"));
+			$def = "\n". $def ."\n";
+		}
+		else {
+			$def = rtrim($def);
+			$def = $this->runSpanGamut($this->outdent($def));
+		}
+
+		return "\n
    " . $def . "
    \n";
+	}
+
+
+	protected function doFencedCodeBlocks($text) {
+	#
+	# Adding the fenced code block syntax to regular Markdown:
+	#
+	# ~~~
+	# Code block
+	# ~~~
+	#
+		$less_than_tab = $this->tab_width;
+		
+		$text = preg_replace_callback('{
+				(?:\n|\A)
+				# 1: Opening marker
+				(
+					(?:~{3,}|`{3,}) # 3 or more tildes/backticks.
+				)
+				[ ]*
+				(?:
+					\.?([-_:a-zA-Z0-9]+) # 2: standalone class name
+				|
+					'.$this->id_class_attr_catch_re.' # 3: Extra attributes
+				)?
+				[ ]* \n # Whitespace and newline following marker.
+				
+				# 4: Content
+				(
+					(?>
+						(?!\1 [ ]* \n)	# Not a closing marker.
+						.*\n+
+					)+
+				)
+				
+				# Closing marker.
+				\1 [ ]* (?= \n )
+			}xm',
+			array($this, '_doFencedCodeBlocks_callback'), $text);
+
+		return $text;
+	}
+	protected function _doFencedCodeBlocks_callback($matches) {
+		$classname =& $matches[2];
+		$attrs     =& $matches[3];
+		$codeblock = $matches[4];
+		$codeblock = htmlspecialchars($codeblock, ENT_NOQUOTES);
+		$codeblock = preg_replace_callback('/^\n+/',
+			array($this, '_doFencedCodeBlocks_newlines'), $codeblock);
+
+		if ($classname != "") {
+			if ($classname{0} == '.')
+				$classname = substr($classname, 1);
+			$attr_str = ' class="'.$this->code_class_prefix.$classname.'"';
+		} else {
+			$attr_str = $this->doExtraAttributes($this->code_attr_on_pre ? "pre" : "code", $attrs);
+		}
+		$pre_attr_str  = $this->code_attr_on_pre ? $attr_str : '';
+		$code_attr_str = $this->code_attr_on_pre ? '' : $attr_str;
+		$codeblock  = "$codeblock
    ";
+		
+		return "\n\n".$this->hashBlock($codeblock)."\n\n";
+	}
+	protected function _doFencedCodeBlocks_newlines($matches) {
+		return str_repeat("empty_element_suffix", 
+			strlen($matches[0]));
+	}
+
+
+	#
+	# Redefining emphasis markers so that emphasis by underscore does not
+	# work in the middle of a word.
+	#
+	protected $em_relist = array(
+		''  => '(?:(? '(? '(? '(?:(? '(? '(? '(?:(? '(? '(? tags
+	#
+		# Strip leading and trailing lines:
+		$text = preg_replace('/\A\n+|\n+\z/', '', $text);
+		
+		$grafs = preg_split('/\n{2,}/', $text, -1, PREG_SPLIT_NO_EMPTY);
+
+		#
+		# Wrap 
     tags and unhashify HTML blocks
+		#
+		foreach ($grafs as $key => $value) {
+			$value = trim($this->runSpanGamut($value));
+			
+			# Check if this should be enclosed in a paragraph.
+			# Clean tag hashes & block tag hashes are left alone.
+			$is_p = !preg_match('/^B\x1A[0-9]+B|^C\x1A[0-9]+C$/', $value);
+			
+			if ($is_p) {
+				$value = "
    $value
    ";
+			}
+			$grafs[$key] = $value;
+		}
+		
+		# Join grafs in one text, then unhash HTML tags. 
+		$text = implode("\n\n", $grafs);
+		
+		# Finish by removing any tag hashes still present in $text.
+		$text = $this->unhash($text);
+		
+		return $text;
+	}
+	
+	
+	### Footnotes
+	
+	protected function stripFootnotes($text) {
+	#
+	# Strips link definitions from text, stores the URLs and titles in
+	# hash references.
+	#
+		$less_than_tab = $this->tab_width - 1;
+
+		# Link defs are in the form: [^id]: url "optional title"
+		$text = preg_replace_callback('{
+			^[ ]{0,'.$less_than_tab.'}\[\^(.+?)\][ ]?:	# note_id = $1
+			  [ ]*
+			  \n?					# maybe *one* newline
+			(						# text = $2 (no blank lines allowed)
+				(?:					
+					.+				# actual text
+				|
+					\n				# newlines but 
+					(?!\[.+?\][ ]?:\s)# negative lookahead for footnote or link definition marker.
+					(?!\n+[ ]{0,3}\S)# ensure line is not blank and followed 
+									# by non-indented content
+				)*
+			)		
+			}xm',
+			array($this, '_stripFootnotes_callback'),
+			$text);
+		return $text;
+	}
+	protected function _stripFootnotes_callback($matches) {
+		$note_id = $this->fn_id_prefix . $matches[1];
+		$this->footnotes[$note_id] = $this->outdent($matches[2]);
+		return ''; # String that will replace the block
+	}
+
+
+	protected function doFootnotes($text) {
+	#
+	# Replace footnote references in $text [^id] with a special text-token 
+	# which will be replaced by the actual footnote marker in appendFootnotes.
+	#
+		if (!$this->in_anchor) {
+			$text = preg_replace('{\[\^(.+?)\]}', "F\x1Afn:\\1\x1A:", $text);
+		}
+		return $text;
+	}
+
+	
+	protected function appendFootnotes($text) {
+	#
+	# Append footnote list to text.
+	#
+		$text = preg_replace_callback('{F\x1Afn:(.*?)\x1A:}', 
+			array($this, '_appendFootnotes_callback'), $text);
+	
+		if (!empty($this->footnotes_ordered)) {
+			$text .= "\n\n";
+			$text .= "
    \n";
+			$text .= "empty_element_suffix ."\n";
+			$text .= "
      \n\n";
+
+			$attr = "";
+			if ($this->fn_backlink_class != "") {
+				$class = $this->fn_backlink_class;
+				$class = $this->encodeAttribute($class);
+				$attr .= " class=\"$class\"";
+			}
+			if ($this->fn_backlink_title != "") {
+				$title = $this->fn_backlink_title;
+				$title = $this->encodeAttribute($title);
+				$attr .= " title=\"$title\"";
+			}
+			$num = 0;
+			
+			while (!empty($this->footnotes_ordered)) {
+				$footnote = reset($this->footnotes_ordered);
+				$note_id = key($this->footnotes_ordered);
+				unset($this->footnotes_ordered[$note_id]);
+				$ref_count = $this->footnotes_ref_count[$note_id];
+				unset($this->footnotes_ref_count[$note_id]);
+				unset($this->footnotes[$note_id]);
+				
+				$footnote .= "\n"; # Need to append newline before parsing.
+				$footnote = $this->runBlockGamut("$footnote\n");				
+				$footnote = preg_replace_callback('{F\x1Afn:(.*?)\x1A:}', 
+					array($this, '_appendFootnotes_callback'), $footnote);
+				
+				$attr = str_replace("%%", ++$num, $attr);
+				$note_id = $this->encodeAttribute($note_id);
+
+				# Prepare backlink, multiple backlinks if multiple references
+				$backlink = "↩";
+				for ($ref_num = 2; $ref_num <= $ref_count; ++$ref_num) {
+					$backlink .= " ↩";
+				}
+				# Add backlink to last paragraph; create new paragraph if needed.
+				if (preg_match('{
      $}', $footnote)) {
+					$footnote = substr($footnote, 0, -4) . " $backlink
      ";
+				} else {
+					$footnote .= "\n\n
      $backlink
      ";
+				}
+				
+				$text .= "
    1. \n";
+				$text .= $footnote . "\n";
+				$text .= "
      2. \n\n";
+			}
+			
+			$text .= "
    \n";
+			$text .= "
    ";
+		}
+		return $text;
+	}
+	protected function _appendFootnotes_callback($matches) {
+		$node_id = $this->fn_id_prefix . $matches[1];
+		
+		# Create footnote marker only if it has a corresponding footnote *and*
+		# the footnote hasn't been used by another marker.
+		if (isset($this->footnotes[$node_id])) {
+			$num =& $this->footnotes_numbers[$node_id];
+			if (!isset($num)) {
+				# Transfer footnote content to the ordered list and give it its
+				# number
+				$this->footnotes_ordered[$node_id] = $this->footnotes[$node_id];
+				$this->footnotes_ref_count[$node_id] = 1;
+				$num = $this->footnote_counter++;
+				$ref_count_mark = '';
+			} else {
+				$ref_count_mark = $this->footnotes_ref_count[$node_id] += 1;
+			}
+
+			$attr = "";
+			if ($this->fn_link_class != "") {
+				$class = $this->fn_link_class;
+				$class = $this->encodeAttribute($class);
+				$attr .= " class=\"$class\"";
+			}
+			if ($this->fn_link_title != "") {
+				$title = $this->fn_link_title;
+				$title = $this->encodeAttribute($title);
+				$attr .= " title=\"$title\"";
+			}
+			
+			$attr = str_replace("%%", $num, $attr);
+			$node_id = $this->encodeAttribute($node_id);
+			
+			return
+				"".
+				"$num".
+				"";
+		}
+		
+		return "[^".$matches[1]."]";
+	}
+		
+	
+	### Abbreviations ###
+	
+	protected function stripAbbreviations($text) {
+	#
+	# Strips abbreviations from text, stores titles in hash references.
+	#
+		$less_than_tab = $this->tab_width - 1;
+
+		# Link defs are in the form: [id]*: url "optional title"
+		$text = preg_replace_callback('{
+			^[ ]{0,'.$less_than_tab.'}\*\[(.+?)\][ ]?:	# abbr_id = $1
+			(.*)					# text = $2 (no blank lines allowed)	
+			}xm',
+			array($this, '_stripAbbreviations_callback'),
+			$text);
+		return $text;
+	}
+	protected function _stripAbbreviations_callback($matches) {
+		$abbr_word = $matches[1];
+		$abbr_desc = $matches[2];
+		if ($this->abbr_word_re)
+			$this->abbr_word_re .= '|';
+		$this->abbr_word_re .= preg_quote($abbr_word);
+		$this->abbr_desciptions[$abbr_word] = trim($abbr_desc);
+		return ''; # String that will replace the block
+	}
+	
+	
+	protected function doAbbreviations($text) {
+	#
+	# Find defined abbreviations in text and wrap them in  elements.
+	#
+		if ($this->abbr_word_re) {
+			// cannot use the /x modifier because abbr_word_re may 
+			// contain significant spaces:
+			$text = preg_replace_callback('{'.
+				'(?abbr_word_re.')'.
+				'(?![\w\x1A])'.
+				'}', 
+				array($this, '_doAbbreviations_callback'), $text);
+		}
+		return $text;
+	}
+	protected function _doAbbreviations_callback($matches) {
+		$abbr = $matches[0];
+		if (isset($this->abbr_desciptions[$abbr])) {
+			$desc = $this->abbr_desciptions[$abbr];
+			if (empty($desc)) {
+				return $this->hashPart("$abbr");
+			} else {
+				$desc = $this->encodeAttribute($desc);
+				return $this->hashPart("$abbr");
+			}
+		} else {
+			return $matches[0];
+		}
+	}
+
+}
diff --git a/library/php-markdown/Michelf/MarkdownExtra.inc.php b/library/php-markdown/Michelf/MarkdownExtra.inc.php
new file mode 100644
index 0000000000..e11b1ef971
--- /dev/null
+++ b/library/php-markdown/Michelf/MarkdownExtra.inc.php
@@ -0,0 +1,11 @@
+
+#
+# Original Markdown
+# Copyright (c) 2004-2006 John Gruber  
+# 
+#
+namespace Michelf;
+
+
+# Just force Michelf/Markdown.php to load. This is needed to load
+# the temporary implementation class. See below for details.
+\Michelf\Markdown::MARKDOWNLIB_VERSION;
+
+#
+# Markdown Extra Parser Class
+#
+# Note: Currently the implementation resides in the temporary class
+# \Michelf\MarkdownExtra_TmpImpl (in the same file as \Michelf\Markdown).
+# This makes it easier to propagate the changes between the three different
+# packaging styles of PHP Markdown. Once this issue is resolved, the
+# _MarkdownExtra_TmpImpl will disappear and this one will contain the code.
+#
+
+class MarkdownExtra extends \Michelf\_MarkdownExtra_TmpImpl {
+
+	### Parser Implementation ###
+
+	# Temporarily, the implemenation is in the _MarkdownExtra_TmpImpl class.
+	# See note above.
+
+}
+
diff --git a/library/php-markdown/Michelf/MarkdownInterface.inc.php b/library/php-markdown/Michelf/MarkdownInterface.inc.php
new file mode 100644
index 0000000000..a023ed4e3a
--- /dev/null
+++ b/library/php-markdown/Michelf/MarkdownInterface.inc.php
@@ -0,0 +1,9 @@
+
+#
+# Original Markdown
+# Copyright (c) 2004-2006 John Gruber
+# 
+#
+namespace Michelf;
+
+
+#
+# Markdown Parser Interface
+#
+
+interface MarkdownInterface {
+
+  #
+  # Initialize the parser and return the result of its transform method.
+  # This will work fine for derived classes too.
+  #
+  public static function defaultTransform($text);
+
+  #
+  # Main function. Performs some preprocessing on the input text
+  # and pass it through the document gamut.
+  #
+  public function transform($text);
+
+}
diff --git a/library/php-markdown/Readme.md b/library/php-markdown/Readme.md
new file mode 100644
index 0000000000..80504c27c2
--- /dev/null
+++ b/library/php-markdown/Readme.md
@@ -0,0 +1,315 @@
+PHP Markdown
+============
+
+PHP Markdown Lib 1.4.1 - 4 May 2013
+
+by Michel Fortin  
+
+
+based on Markdown by John Gruber  
+
+
+
+Introduction
+------------
+
+This is a library package that includes the PHP Markdown parser and its 
+sibling PHP Markdown Extra with additional features.
+
+Markdown is a text-to-HTML conversion tool for web writers. Markdown
+allows you to write using an easy-to-read, easy-to-write plain text
+format, then convert it to structurally valid XHTML (or HTML).
+
+"Markdown" is actually two things: a plain text markup syntax, and a 
+software tool, originally written in Perl, that converts the plain text 
+markup to HTML. PHP Markdown is a port to PHP of the original Markdown 
+program by John Gruber.
+
+*	[Full documentation of the Markdown syntax]()
+	- Daring Fireball (John Gruber)
+*	[Markdown Extra syntax additions]()
+	- Michel Fortin
+
+
+Requirement
+-----------
+
+This library package requires PHP 5.3 or later.
+
+Note: The older plugin/library hybrid package for PHP Markdown and
+PHP Markdown Extra is still maintained and will work with PHP 4.0.5 and later.
+
+Before PHP 5.3.7, pcre.backtrack_limit defaults to 100 000, which is too small
+in many situations. You might need to set it to higher values. Later PHP 
+releases defaults to 1 000 000, which is usually fine.
+
+
+Usage
+-----
+
+This library package is meant to be used with class autoloading. For autoloading 
+to work, your project needs have setup a PSR-0-compatible autoloader. See the 
+included Readme.php file for a minimal autoloader setup. (If you cannot use 
+autoloading, see below.)
+
+With class autoloading in place, putting the 'Michelf' folder in your 
+include path should be enough for this to work:
+
+	use \Michelf\Markdown;
+	$my_html = Markdown::defaultTransform($my_text);
+
+Markdown Extra syntax is also available the same way:
+
+	use \Michelf\MarkdownExtra;
+	$my_html = MarkdownExtra::defaultTransform($my_text);
+
+If you wish to use PHP Markdown with another text filter function 
+built to parse HTML, you should filter the text *after* the `transform`
+function call. This is an example with [PHP SmartyPants][psp]:
+
+	use \Michelf\Markdown, \Michelf\SmartyPants;
+	$my_html = Markdown::defaultTransform($my_text);
+	$my_html = SmartyPants::defaultTransform($my_html);
+
+All these examples are using the static `defaultTransform` static function 
+found inside the parser class. If you want to customize the parser 
+configuration, you can also instantiate it directly and change some 
+configuration variables:
+
+	use \Michelf\MarkdownExtra;
+	$parser = new MarkdownExtra;
+	$parser->fn_id_prefix = "post22-";
+	$my_html = $parser->transform($my_text);
+
+To learn more, see the full list of [configuration variables].
+
+ [configuration variables]: http://michelf.ca/projects/php-markdown/configuration/
+
+
+### Usage without an autoloader
+
+If you cannot use class autoloading, you can still use `include` or `require` 
+to access the parser. To load the `\Michelf\Markdown` parser, do it this way:
+
+	require_once 'Michelf/Markdown.inc.php';
+
+Or, if you need the `\Michelf\MarkdownExtra` parser:
+
+	require_once 'Michelf/MarkdownExtra.inc.php';
+
+While the plain `.php` files depend on autoloading to work correctly, using the
+`.inc.php` files instead will eagerly load the dependencies that would be 
+loaded on demand if you were using autoloading.
+
+
+Public API and Versioning Policy
+---------------------------------
+
+Version numbers are of the form *major*.*minor*.*patch*.
+
+The public API of PHP Markdown consist of the two parser classes `Markdown`
+and `MarkdownExtra`, their constructors, the `transform` and `defaultTransform`
+functions and their configuration variables. The public API is stable for
+a given major version number. It might get additions when the minor version
+number increments.
+
+**Protected members are not considered public API.** This is unconventional 
+and deserves an explanation. Incrementing the major version number every time 
+the underlying implementation of something changes is going to give
+nonessential version numbers for the vast majority of people who just use the
+parser.  Protected members are meant to create parser subclasses that behave in
+different ways. Very few people create parser subclasses. I don't want to 
+discourage it by making everything private, but at the same time I can't 
+guarantee any stable hook between versions if you use protected members.
+
+**Syntax changes** will increment the minor number for new features, and the 
+patch number for small corrections. A *new feature* is something that needs a 
+change in the syntax documentation. Note that since PHP Markdown Lib includes
+two parsers, a syntax change for either of them will increment the minor 
+number. Also note that there is nothing perfectly backward-compatible with the
+Markdown syntax: all inputs are always valid, so new features always replace
+something that was previously legal, although generally nonsensical to do.
+
+
+Bugs
+----
+
+To file bug reports please send email to:
+
+
+Please include with your report: (1) the example input; (2) the output you
+expected; (3) the output PHP Markdown actually produced.
+
+If you have a problem where Markdown gives you an empty result, first check 
+that the backtrack limit is not too low by running `php --info | grep pcre`.
+See Installation and Requirement above for details.
+
+
+Development and Testing
+-----------------------
+
+Pull requests for fixing bugs are welcome. Proposed new features are
+going meticulously reviewed -- taking into account backward compatibility, 
+potential side effects, and future extensibility -- before deciding on
+acceptance or rejection.
+
+If you make a pull request that includes changes to the parser please add 
+tests for what is being changed to [MDTest][] and make a pull request there 
+too.
+
+ [MDTest]: https://github.com/michelf/mdtest/
+
+
+Donations
+---------
+
+If you wish to make a donation that will help me devote more time to 
+PHP Markdown, please visit [michelf.ca/donate] or send Bitcoin to
+[1HiuX34czvVPPdhXbUAsAu7pZcesniDCGH].
+
+ [michelf.ca/donate]: https://michelf.ca/donate/#!Thanks%20for%20PHP%20Markdown
+ [1HiuX34czvVPPdhXbUAsAu7pZcesniDCGH]: bitcoin:1HiuX34czvVPPdhXbUAsAu7pZcesniDCGH
+
+
+Version History
+---------------
+
+Unreleased
+
+*	Added the ability to insert custom HTML attributes everywhere an extra
+	attribute block is allowed (links, images, headers). Credits to
+	Peter Droogmans for providing the implementation.
+
+*	Added a `url_filter_func` configuration variable which takes a function
+	that can rewrite any link or image URL to something different.
+
+
+PHP Markdown Lib 1.4.1 (4 May 2014)
+
+*	The HTML block parser will now treat `
    ` as a block-level element
+	(as it should) and no longer wrap it in `
    ` or parse it's content with 
+	the as Markdown syntax (although with Extra you can use `markdown="1"`
+	if you wish to use the Markdown syntax inside it).
+
+*	The content of `