From 21c48a147655378bef133aa9fd3f5aa162a21675 Mon Sep 17 00:00:00 2001 From: Friendika Date: Mon, 11 Apr 2011 05:59:26 -0700 Subject: [PATCH] markdown parser --- library/markdown.php | 3042 ++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 3042 insertions(+) create mode 100644 library/markdown.php diff --git a/library/markdown.php b/library/markdown.php new file mode 100644 index 0000000000..d51dceecaf --- /dev/null +++ b/library/markdown.php @@ -0,0 +1,3042 @@ + +# +# Original Markdown +# Copyright (c) 2004-2006 John Gruber +# +# + + +define( 'MARKDOWN_VERSION', "1.0.1m" ); # Sat 21 Jun 2008 +define( 'MARKDOWNEXTRA_VERSION', "1.2.3" ); # Wed 31 Dec 2008 + + +# +# Global default settings: +# + +# Change to ">" for HTML output +@define( 'MARKDOWN_EMPTY_ELEMENT_SUFFIX', " />"); + +# Define the width of a tab for code blocks. +@define( 'MARKDOWN_TAB_WIDTH', 4 ); + +# Optional title attribute for footnote links and backlinks. +@define( 'MARKDOWN_FN_LINK_TITLE', "" ); +@define( 'MARKDOWN_FN_BACKLINK_TITLE', "" ); + +# Optional class attribute for footnote links and backlinks. +@define( 'MARKDOWN_FN_LINK_CLASS', "" ); +@define( 'MARKDOWN_FN_BACKLINK_CLASS', "" ); + +# Enables special handling for links pointing outside of the current domain. +@define( 'MARKDOWN_EL_ENABLE', true); # Use this feature at all? +@define( 'MARKDOWN_EL_LOCAL_DOMAIN', null); # Leave as null to autodetect +@define( 'MARKDOWN_EL_NEW_WINDOW', true); # Open link in a new browser? +@define( 'MARKDOWN_EL_CSS_CLASS', 'external'); # Leave as null for no class + +# Enables header auto-self-linking. +@define( 'MARKDOWN_HA_ENABLE', true ); # Use this feature at all? +@define( 'MARKDOWN_HA_CLASS', 'hidden-selflink' ); # Leave as null for no class +@define( 'MARKDOWN_HA_TEXT', '←' ); # The text to use as the link + + +# +# WordPress settings: +# + +# Change to false to remove Markdown from posts and/or comments. +@define( 'MARKDOWN_WP_POSTS', true ); +@define( 'MARKDOWN_WP_COMMENTS', true ); + + + +### Standard Function Interface ### + +@define( 'MARKDOWN_PARSER_CLASS', 'MarkdownExtra_Parser' ); + +function Markdown($text) { +# +# Initialize the parser and return the result of its transform method. +# + # Setup static parser variable. + static $parser; + if (!isset($parser)) { + $parser_class = MARKDOWN_PARSER_CLASS; + $parser = new $parser_class; + } + + # Transform text using parser. + return $parser->transform($text); +} + + +### WordPress Plugin Interface ### + +/* +Plugin Name: Markdown Extra +Plugin URI: http://www.michelf.com/projects/php-markdown/ +Description: Markdown syntax allows you to write using an easy-to-read, easy-to-write plain text format. Based on the original Perl version by John Gruber. More... +Version: 1.2.2 +Author: Michel Fortin +Author URI: http://www.michelf.com/ +*/ + +if (isset($wp_version)) { + # More details about how it works here: + # + + # Post content and excerpts + # - Remove WordPress paragraph generator. + # - Run Markdown on excerpt, then remove all tags. + # - Add paragraph tag around the excerpt, but remove it for the excerpt rss. + if (MARKDOWN_WP_POSTS) { + remove_filter('the_content', 'wpautop'); + remove_filter('the_content_rss', 'wpautop'); + remove_filter('the_excerpt', 'wpautop'); + add_filter('the_content', 'mdwp_MarkdownPost', 6); + add_filter('the_content_rss', 'mdwp_MarkdownPost', 6); + add_filter('get_the_excerpt', 'mdwp_MarkdownPost', 6); + add_filter('get_the_excerpt', 'trim', 7); + add_filter('the_excerpt', 'mdwp_add_p'); + add_filter('the_excerpt_rss', 'mdwp_strip_p'); + + remove_filter('content_save_pre', 'balanceTags', 50); + remove_filter('excerpt_save_pre', 'balanceTags', 50); + add_filter('the_content', 'balanceTags', 50); + add_filter('get_the_excerpt', 'balanceTags', 9); + } + + # Add a footnote id prefix to posts when inside a loop. + function mdwp_MarkdownPost($text) { + static $parser; + if (!$parser) { + $parser_class = MARKDOWN_PARSER_CLASS; + $parser = new $parser_class; + } + if (is_single() || is_page() || is_feed()) { + $parser->fn_id_prefix = ""; + } else { + $parser->fn_id_prefix = get_the_ID() . "."; + } + return $parser->transform($text); + } + + # Comments + # - Remove WordPress paragraph generator. + # - Remove WordPress auto-link generator. + # - Scramble important tags before passing them to the kses filter. + # - Run Markdown on excerpt then remove paragraph tags. + if (MARKDOWN_WP_COMMENTS) { + remove_filter('comment_text', 'wpautop', 30); + remove_filter('comment_text', 'make_clickable'); + add_filter('pre_comment_content', 'Markdown', 6); + add_filter('pre_comment_content', 'mdwp_hide_tags', 8); + add_filter('pre_comment_content', 'mdwp_show_tags', 12); + add_filter('get_comment_text', 'Markdown', 6); + add_filter('get_comment_excerpt', 'Markdown', 6); + add_filter('get_comment_excerpt', 'mdwp_strip_p', 7); + + global $mdwp_hidden_tags, $mdwp_placeholders; + $mdwp_hidden_tags = explode(' ', + '
    • '); + $mdwp_placeholders = explode(' ', str_rot13( + 'pEj07ZbbBZ U1kqgh4w4p pre2zmeN6K QTi31t9pre ol0MP1jzJR '. + 'ML5IjmbRol ulANi1NsGY J7zRLJqPul liA8ctl16T K9nhooUHli')); + } + + function mdwp_add_p($text) { + if (!preg_match('{^$|^<(p|ul|ol|dl|pre|blockquote)>}i', $text)) { + $text = '

    '.$text.'

    '; + $text = preg_replace('{\n{2,}}', "

    \n\n

    ", $text); + } + return $text; + } + + function mdwp_strip_p($t) { return preg_replace('{}i', '', $t); } + + function mdwp_hide_tags($text) { + global $mdwp_hidden_tags, $mdwp_placeholders; + return str_replace($mdwp_hidden_tags, $mdwp_placeholders, $text); + } + function mdwp_show_tags($text) { + global $mdwp_hidden_tags, $mdwp_placeholders; + return str_replace($mdwp_placeholders, $mdwp_hidden_tags, $text); + } +} + + +### bBlog Plugin Info ### + +function identify_modifier_markdown() { + return array( + 'name' => 'markdown', + 'type' => 'modifier', + 'nicename' => 'PHP Markdown Extra', + 'description' => 'A text-to-HTML conversion tool for web writers', + 'authors' => 'Michel Fortin and John Gruber', + 'licence' => 'GPL', + 'version' => MARKDOWNEXTRA_VERSION, + 'help' => 'Markdown syntax allows you to write using an easy-to-read, easy-to-write plain text format. Based on the original Perl version by John Gruber. More...', + ); +} + + +### Smarty Modifier Interface ### + +function smarty_modifier_markdown($text) { + return Markdown($text); +} + + +### Textile Compatibility Mode ### + +# Rename this file to "classTextile.php" and it can replace Textile everywhere. + +if (strcasecmp(substr(__FILE__, -16), "classTextile.php") == 0) { + # Try to include PHP SmartyPants. Should be in the same directory. + @include_once 'smartypants.php'; + # Fake Textile class. It calls Markdown instead. + class Textile { + function TextileThis($text, $lite='', $encode='') { + if ($lite == '' && $encode == '') $text = Markdown($text); + if (function_exists('SmartyPants')) $text = SmartyPants($text); + return $text; + } + # Fake restricted version: restrictions are not supported for now. + function TextileRestricted($text, $lite='', $noimage='') { + return $this->TextileThis($text, $lite); + } + # Workaround to ensure compatibility with TextPattern 4.0.3. + function blockLite($text) { return $text; } + } +} + + + +# +# Markdown Parser Class +# + +class Markdown_Parser { + + # Regex to match balanced [brackets]. + # Needed to insert a maximum bracked depth while converting to PHP. + var $nested_brackets_depth = 6; + var $nested_brackets_re; + + var $nested_url_parenthesis_depth = 4; + var $nested_url_parenthesis_re; + + # Table of hash values for escaped characters: + var $escape_chars = '\`*_{}[]()>#+-.!'; + var $escape_chars_re; + + # Change to ">" for HTML output. + var $empty_element_suffix = MARKDOWN_EMPTY_ELEMENT_SUFFIX; + var $tab_width = MARKDOWN_TAB_WIDTH; + + # Change to `true` to disallow markup or entities. + var $no_markup = false; + var $no_entities = false; + + # Predefined urls and titles for reference links and images. + var $predef_urls = array(); + var $predef_titles = array(); + + + function Markdown_Parser() { + # + # 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. + var $urls = array(); + var $titles = array(); + var $html_hashes = array(); + + # Status flag to avoid invalid nesting. + var $in_anchor = false; + + + 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(); + + $in_anchor = false; + } + + function teardown() { + # + # Called after the transformation process to clear any variable + # which may be taking up memory unnecessarly. + # + $this->urls = array(); + $this->titles = array(); + $this->html_hashes = array(); + } + + + function transform($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"; + } + + var $document_gamut = array( + # Strip link definitions, store in hashes. + "stripLinkDefinitions" => 20, + + "runBasicBlockGamut" => 30, + ); + + + function stripLinkDefinitions($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 + [ ]* + \n? # maybe one newline + [ ]* + (?: + (?<=\s) # lookbehind for whitespace + ["(] + (.*?) # title = $3 + [")] + [ ]* + )? # title is optional + (?:\n+|\Z) + }xm', + array(&$this, '_stripLinkDefinitions_callback'), + $text); + return $text; + } + function _stripLinkDefinitions_callback($matches) { + $link_id = strtolower($matches[1]); + $this->urls[$link_id] = $matches[2]; + $this->titles[$link_id] =& $matches[3]; + return ''; # String that will replace the block + } + + + function hashHTMLBlocks($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|form|fieldset|iframe|math|textarea'; + + # 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\n) # Starting after a blank line + | # or + \A\n? # the 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 $text; + } + function _hashHTMLBlocks_callback($matches) { + $text = $matches[1]; + $key = $this->hashBlock($text); + return "\n\n$key\n\n"; + } + + + function hashPart($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 $key; # String that will replace the tag. + } + + + function hashBlock($text) { + # + # Shortcut function for hashPart with block-level boundaries. + # + return $this->hashPart($text, 'B'); + } + + + var $block_gamut = array( + # + # These are all the transformations that form block-level + # tags like paragraphs, headers, and list items. + # + "doHeaders" => 10, + "doHorizontalRules" => 20, + + "doLists" => 40, + "doCodeBlocks" => 50, + "doBlockQuotes" => 60, + ); + + function runBlockGamut($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); + } + + 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 $text; + } + + + function doHorizontalRules($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); + } + + + var $span_gamut = array( + # + # These are all the transformations that occur *within* block-level + # tags like paragraphs, headers, and list items. + # + # Process character escapes, code spans, and inline HTML + # in one shot. + "parseSpan" => -30, + + # Process anchor and image tags. Images must come first, + # because ![foo][f] looks like an anchor. + "doImages" => 10, + "doAnchors" => 20, + + # Make links out of things like `` + # Must come after doAnchors, because you can use < and > + # delimiters in inline links like [this](). + "doAutoLinks" => 30, + "encodeAmpsAndAngles" => 40, + + "doItalicsAndBold" => 50, + "doHardBreaks" => 60, + ); + + function runSpanGamut($text) { + # + # Run span gamut tranformations. + # + foreach ($this->span_gamut as $method => $priority) { + $text = $this->$method($text); + } + + return $text; + } + + + function doHardBreaks($text) { + # Do hard breaks: + return preg_replace_callback('/ {2,}\n/', + array(&$this, '_doHardBreaks_callback'), $text); + } + function _doHardBreaks_callback($matches) { + return $this->hashPart("empty_element_suffix\n"); + } + + + function doAnchors($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 + \[ + ('.$this->nested_brackets_re.') # link text = $2 + \] + \( # literal paren + [ ]* + (?: + <(\S*)> # href = $3 + | + ('.$this->nested_url_parenthesis_re.') # href = $4 + ) + [ ]* + ( # $5 + ([\'"]) # quote char = $6 + (.*?) # Title = $7 + \6 # matching quote + [ ]* # ignore any spaces/tabs between closing quote and ) + )? # title is optional + \) + ) + }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 test][1] + # or [link test](/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 $text; + } + function _doAnchors_reference_callback($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 = $this->encodeAttribute($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 $result; + } + function _doAnchors_inline_callback($matches) { + $whole_match = $matches[1]; + $link_text = $this->runSpanGamut($matches[2]); + $url = $matches[3] == '' ? $matches[4] : $matches[3]; + $title =& $matches[7]; + + $url = $this->encodeAttribute($url); + + $result = "encodeAttribute($title); + $result .= " title=\"$title\""; + } + + $link_text = $this->runSpanGamut($link_text); + $result .= ">$link_text"; + + return $this->hashPart($result); + } + + + 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 + \( # literal paren + [ ]* + (?: + <(\S*)> # src url = $3 + | + ('.$this->nested_url_parenthesis_re.') # src url = $4 + ) + [ ]* + ( # $5 + ([\'"]) # quote char = $6 + (.*?) # title = $7 + \6 # matching quote + [ ]* + )? # title is optional + \) + ) + }xs', + array(&$this, '_doImages_inline_callback'), $text); + + return $text; + } + function _doImages_reference_callback($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 = $this->encodeAttribute($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 $result; + } + function _doImages_inline_callback($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 = $this->encodeAttribute($url); + $result = "\"$alt_text\"";encodeAttribute($title); + $result .= " title=\"$title\""; # $title already quoted + } + $result .= $this->empty_element_suffix; + + return $this->hashPart($result); + } + + + 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 $text; + } + function _doHeaders_callback_setext($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"; + } + function _doHeaders_callback_atx($matches) { + $level = strlen($matches[1]); + $block = "".$this->runSpanGamut($matches[2]).""; + return "\n" . $this->hashBlock($block) . "\n\n"; + } + + + 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+[.]'; + $marker_any_re = "(?:$marker_ul_re|$marker_ol_re)"; + + $markers_relist = array($marker_ul_re, $marker_ol_re); + + foreach ($markers_relist as $marker_re) { + # Re-usable pattern to match any entirel ul or ol list: + $whole_list_re = ' + ( # $1 = whole list + ( # $2 + [ ]{0,'.$less_than_tab.'} + ('.$marker_re.') # $3 = first list item marker + [ ]+ + ) + (?s:.+?) + ( # $4 + \z + | + \n{2,} + (?=\S) + (?! # Negative lookahead for another list item marker + [ ]* + '.$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 $text; + } + function _doLists_callback($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[3]) ? "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"; + } + + var $list_level = 0; + + function processListItems($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 $list_str; + } + function _processListItems_callback($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 "
  • " . $item . "
    • \n"; + } + + + function doCodeBlocks($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 $text;
+	}
+	function _doCodeBlocks_callback($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($codeblock)."\n\n";
+	}
+
+
+	function makeCodeSpan($code) {
+	#
+	# Create a code span markup for $code. Called from handleSpanToken.
+	#
+		$code = htmlspecialchars(trim($code), ENT_NOQUOTES);
+		return $this->hashPart("$code");
+	}
+
+
+	var $em_relist = array(
+		''  => '(?:(? '(?<=\S)(? '(?<=\S)(? '(?:(? '(?<=\S)(? '(?<=\S)(? '(?:(? '(?<=\S)(? '(?<=\S)(?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"] = $token_re;
+			}
+		}
+	}
+
+	function doItalicsAndBold($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 seach 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 $text_stack[0];
+	}
+
+
+	function doBlockQuotes($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 $text;
+	}
+	function _doBlockQuotes_callback($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";
+	}
+	function _doBlockQuotes_callback2($matches) {
+		$pre = $matches[1];
+		$pre = preg_replace('/^  /m', '', $pre);
+		return $pre;
+	}
+
+
+	function formParagraphs($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", $grafs);
+	}
+
+
+	function encodeAttribute($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 $text;
+	}
+
+
+	function encodeAmpsAndAngles($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 $text;
+	}
+
+
+	function doAutoLinks($text) {
+		$text = preg_replace_callback('{<((https?|ftp|dict):[^\'">\s]+)>}i',
+			array(&$this, '_doAutoLinks_url_callback'), $text);
+
+		# Email addresses: 
+		$text = preg_replace_callback('{
+			<
+			(?:mailto:)?
+			(
+				[-.\w\x80-\xFF]+
+				\@
+				[-a-z0-9\x80-\xFF]+(\.[-a-z0-9\x80-\xFF]+)*\.[a-z]+
+			)
+			>
+			}xi',
+			array(&$this, '_doAutoLinks_email_callback'), $text);
+
+		return $text;
+	}
+	function _doAutoLinks_url_callback($matches) {
+		$url = $this->encodeAttribute($matches[1]);
+		$link = "$url";
+		return $this->hashPart($link);
+	}
+	function _doAutoLinks_email_callback($matches) {
+		$address = $matches[1];
+		$link = $this->encodeEmailAddress($address);
+		return $this->hashPart($link);
+	}
+
+
+	function encodeEmailAddress($addr) {
+	#
+	#	Input: an email address, e.g. "foo@example.com"
+	#
+	#	Output: the email address as a mailto link, with each character
+	#		of the address encoded as either a decimal or hex entity, in
+	#		the hopes of foiling most address harvesting spam bots. E.g.:
+	#
+	#	  
    foo@exampl
+	#        e.com
    
+	#
+	#	Based by a filter by Matthew Wickline, posted to BBEdit-Talk.
+	#   With some optimizations by Milian Wolff.
+	#
+		$addr = "mailto:" . $addr;
+		$chars = preg_split('/(? $char) {
+			$ord = ord($char);
+			# Ignore non-ascii chars.
+			if ($ord < 128) {
+				$r = ($seed * (1 + $key)) % 100; # Pseudo-random function.
+				# roughly 10% raw, 45% hex, 45% dec
+				# '@' *must* be encoded. I insist.
+				if ($r > 90 && $char != '@') /* do nothing */;
+				else if ($r < 45) $chars[$key] = '&#x'.dechex($ord).';';
+				else              $chars[$key] = '&#'.$ord.';';
+			}
+		}
+
+		$addr = implode('', $chars);
+		$text = implode('', array_slice($chars, 7)); # text without `mailto:`
+		$addr = "$text";
+
+		return $addr;
+	}
+
+
+	function parseSpan($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
+						(?>[^"\'>]+|"[^"]*"|\'[^\']*\')*
+					)?
+					>
+			').'
+				)
+				}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 $output;
+	}
+
+
+	function handleSpanToken($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);
+		}
+	}
+
+
+	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.
+	var $utf8_strlen = 'mb_strlen';
+
+	function detab($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 $text;
+	}
+	function _detab_callback($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 $line;
+	}
+	function _initDetab() {
+	#
+	# Check for the availability of the function in the `utf8_strlen` property
+	# (initially `mb_strlen`). If the function is not available, create a
+	# function that will loosely count the number of UTF-8 characters with a
+	# regular expression.
+	#
+		if (function_exists($this->utf8_strlen)) return;
+		$this->utf8_strlen = create_function('$text', 'return preg_match_all(
+			"/[\\\\x00-\\\\xBF]|[\\\\xC0-\\\\xFF][\\\\x80-\\\\xBF]*/",
+			$text, $m);');
+	}
+
+
+	function unhash($text) {
+	#
+	# Swap back in all the tags hashed by _HashHTMLBlocks.
+	#
+		return preg_replace_callback('/(.)\x1A[0-9]+\1/',
+			array(&$this, '_unhash_callback'), $text);
+	}
+	function _unhash_callback($matches) {
+		return $this->html_hashes[$matches[0]];
+	}
+
+}
+
+
+#
+# Markdown Extra Parser Class
+#
+
+class MarkdownExtra_Parser extends Markdown_Parser {
+
+	# Prefix for footnote ids.
+	var $fn_id_prefix = "";
+
+	# Optional title attribute for footnote links and backlinks.
+	var $fn_link_title = MARKDOWN_FN_LINK_TITLE;
+	var $fn_backlink_title = MARKDOWN_FN_BACKLINK_TITLE;
+
+	# Optional class attribute for footnote links and backlinks.
+	var $fn_link_class = MARKDOWN_FN_LINK_CLASS;
+	var $fn_backlink_class = MARKDOWN_FN_BACKLINK_CLASS;
+
+	var $el_enable = MARKDOWN_EL_ENABLE;
+	var $el_local_domain = MARKDOWN_EL_LOCAL_DOMAIN;
+	var $el_new_window = MARKDOWN_EL_NEW_WINDOW;
+	var $el_css_class = MARKDOWN_EL_CSS_CLASS;
+
+	var $ha_enable = MARKDOWN_HA_ENABLE;
+	var $ha_class = MARKDOWN_HA_CLASS;
+	var $ha_text = MARKDOWN_HA_TEXT;
+
+	# Predefined abbreviations.
+	var $predef_abbr = array();
+
+
+	function MarkdownExtra_Parser() {
+	#
+	# Constructor function. Initialize the parser object.
+	#
+		# Add extra escapable characters before parent constructor
+		# initialize the table.
+		$this->escape_chars .= ':|';
+
+		if ($this->el_local_domain === null) {
+			$this->el_local_domain = $_SERVER['SERVER_NAME'];
+		}
+
+		# 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::Markdown_Parser();
+	}
+
+
+	# Extra variables used during extra transformations.
+	var $footnotes = array();
+	var $footnotes_ordered = array();
+	var $abbr_desciptions = array();
+	var $abbr_word_re = '';
+
+	# Give the current footnote number.
+	var $footnote_counter = 1;
+
+
+	function setup() {
+	#
+	# Setting up Extra-specific variables.
+	#
+		parent::setup();
+
+		$this->footnotes = array();
+		$this->footnotes_ordered = 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);
+		}
+	}
+
+	function teardown() {
+	#
+	# Clearing Extra-specific variables.
+	#
+		$this->footnotes = array();
+		$this->footnotes_ordered = array();
+		$this->abbr_desciptions = array();
+		$this->abbr_word_re = '';
+
+		parent::teardown();
+	}
+
+
+	### HTML Block Parser ###
+
+	# Tags that are always treated as block tags:
+	var $block_tags_re = 'p|div|h[1-6]|blockquote|pre|table|dl|ol|ul|address|form|fieldset|iframe|hr|legend';
+
+	# Tags treated as block tags only if the opening tag is alone on it's line:
+	var $context_block_tags_re = 'script|noscript|math|ins|del';
+
+	# Tags where markdown="1" default to span mode:
+	var $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:
+	var $clean_tags_re = 'script|math';
+
+	# Tags that do not need to be closed.
+	var $auto_close_tags_re = 'hr|img';
+
+
+	function hashHTMLBlocks($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 whitin 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!
+	#
+		#
+		# Call the HTML-in-Markdown hasher.
+		#
+		list($text, ) = $this->_hashHTMLBlocks_inMarkdown($text);
+
+		return $text;
+	}
+	function _hashHTMLBlocks_inMarkdown($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 =
+			'{
+				(					# $2: Capture hole tag.
+									# Tag name.
+							'.$this->block_tags_re.'			|
+							'.$this->context_block_tags_re.'	|
+							'.$this->clean_tags_re.'        	|
+							(?!\s)'.$enclosing_tag_re.'
+						)
+						(?:
+							(?=[\s"\'/a-zA-Z0-9])	# Allowed characters after tag name.
+							(?>
+								".*?"		|	# Double quotes (can contain `>`)
+								\'.*?\'   	|	# Single quotes (can contain `>`)
+								.+?				# Anything but quotes and `>`.
+							)*?
+						)?
+					>					# End of tag.
+				|
+						# HTML Comment
+				|
+					<\?.*?\?> | <%.*?%>	# Processing instruction
+				|
+						# CData Block
+				|
+					# Code span marker
+					`+
+				'. ( !$span ? ' # If not in span.
+				|
+					# Indented code block
+					(?> ^[ ]*\n? | \n[ ]*\n )
+					[ ]{'.($indent+4).'}[^\n]* \n
+					(?>
+						(?: [ ]{'.($indent+4).'}[^\n]* | [ ]* ) \n
+					)*
+				|
+					# Fenced code block marker
+					(?> ^ | \n )
+					[ ]{'.($indent).'}~~~+[ ]*\n
+				' : '' ). ' # End (if not is span).
+				)
+			}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: Code span marker
+			#
+			if ($tag{0} == "`") {
+				# Find corresponding end marker.
+				$tag_re = preg_quote($tag);
+				if (preg_match('{^(?>.+?|\n(?!\n))*?(?.*\n)+?'.$tag_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 .= $tag;
+					}
+				}
+			}
+			#
+			# Check for: Opening Block level tag or
+			#            Opening Context Block tag (like ins and del)
+			#               used as a block tag (tag is alone on it's line).
+			#
+			else if (preg_match('{^<(?:'.$this->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, $text);
+	}
+	function _hashHTMLBlocks_inHTML($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 hole 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 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, $text);
+	}
+
+
+	function hashClean($text) {
+	#
+	# Called whenever a tag must be hashed when a function insert a "clean" tag
+	# in $text, it pass through this function and is automaticaly escaped,
+	# blocking invalid nested overlap.
+	#
+		return $this->hashPart($text, 'C');
+	}
+
+	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];
+
+		$url = $this->encodeAttribute($url);
+
+		$result = "encodeAttribute($title);
+			$result .=  " title=\"$title\"";
+		}
+
+		if ($this->el_enable && preg_match('/^https?\:\/\//', $url) && !preg_match('/^https?\:\/\/'.$this->el_local_domain.'/', $url)) {
+			if ($this->el_new_window) {
+				$result .= ' target="_blank"';
+			}
+
+			if ($this->el_css_class) {
+				$result .= ' class="'.$this->el_css_class.'"';
+			}
+		}
+
+		$link_text = $this->runSpanGamut($link_text);
+		$result .= ">$link_text";
+
+		return $this->hashPart($result);
+	}
+
+	function _doAnchors_reference_callback($matches) {
+		$whole_match =  $matches[1];
+		$link_text   =  $matches[2];
+		$link_id     =& $matches[3];
+		$result      =  '';
+
+		if ($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 = $this->encodeAttribute($url);
+
+			$result = "titles[$link_id] ) ) {
+				$title = $this->titles[$link_id];
+				$title = $this->encodeAttribute($title);
+				$result .=  " title=\"$title\"";
+			}
+
+			if ($this->el_enable && preg_match('/^https?\:\/\//', $url) && !preg_match('/^https?\:\/\/'.$this->el_local_domain.'/', $url)) {
+				if ($this->el_new_window) {
+					$result .= ' target="_blank"';
+				}
+
+				if ($this->el_css_class) {
+					$result .= ' class="'.$this->el_css_class.'"';
+				}
+			}
+
+			$link_text = $this->runSpanGamut($link_text);
+			$result .= ">$link_text";
+			$result = $this->hashPart($result);
+		}
+		else {
+			$result = $whole_match;
+		}
+		return $result;
+	}
+
+	function doHeaders($text) {
+	#
+	# Redefined to add id attribute support.
+	#
+		# Setext-style headers:
+		#	  Header 1  {#header1}
+		#	  ========
+		#
+		#	  Header 2  {#header2}
+		#	  --------
+		#
+		$text = preg_replace_callback(
+			'{
+				(^.+?)								# $1: Header text
+				(?:[ ]+\{\#([-_:a-zA-Z0-9]+)\})?	# $2: Id attribute
+				[ ]*\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}
+		#	...
+		#	###### Header 6   {#header2}
+		#
+		$text = preg_replace_callback('{
+				^(\#{1,6})	# $1 = string of #\'s
+				[ ]*
+				(.+?)		# $2 = Header text
+				[ ]*
+				\#*			# optional closing #\'s (not counted)
+				(?:[ ]+\{\#([-_:a-zA-Z0-9]+)\})? # id attribute
+				[ ]*
+				\n+
+			}xm',
+			array(&$this, '_doHeaders_callback_atx'), $text);
+
+		return $text;
+	}
+	function _doHeaders_attr($attr) {
+		if (empty($attr))  return "";
+		return " id=\"$attr\"";
+	}
+	function _doHeaders_callback_setext($matches) {
+		if ($matches[3] == '-' && preg_match('{^- }', $matches[1]))
+			return $matches[0];
+		$level = $matches[3]{0} == '=' ? 1 : 2;
+		$attr  = $this->_doHeaders_attr($id =& $matches[2]);
+		$body  = $this->runSpanGamut($matches[1]);
+		$body  = $this->_doHeaders_selflink($id, $body);
+
+		$block = "$body";
+		return "\n" . $this->hashBlock($block) . "\n\n";
+	}
+	function _doHeaders_callback_atx($matches) {
+		$level = strlen($matches[1]);
+		$attr  = $this->_doHeaders_attr($id =& $matches[3]);
+		$body  = $this->runSpanGamut($matches[2]);
+		$body = $this->_doHeaders_selflink($id, $body);
+
+		$block = "$body";
+		return "\n" . $this->hashBlock($block) . "\n\n";
+	}
+	function _doHeaders_selflink($id, $body) {
+		if (!empty($id)) {
+			$link = 'ha_class) {
+				$link .= ' class="'.$this->ha_class.'"';
+			}
+
+			$link .= '>'.$this->ha_text.'';
+
+			$body .= $link;
+		}
+
+		return $body;
+	}
+
+
+	function doTables($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 $text;
+	}
+	function _doTable_leadingPipe_callback($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, $content));
+	}
+	function _doTable_callback($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] = ' align="right"';
+			else if (preg_match('/^ *:-+: *$/', $s))$attr[$n] = ' align="center"';
+			else if (preg_match('/^ *:-+ *$/', $s))	$attr[$n] = ' align="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);
+
+		# 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";
+	}
+
+
+	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 $text;
+	}
+	function _doDefLists_callback($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";
+	}
+
+
+	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.'} [:][ ]	|
+					
     0) {
+				$term = preg_replace($anchor_regexp, '', $term);
+				$id = ' id="'.trim($id[1]).'"';
+			}
+
+			if (count($id) === 0) {
+				$id = '';
+			}
+
+			$term = $this->runSpanGamut(trim($term));
+			$text .= "\n" . $term . "
    ";
+		}
+		return $text . "\n";
+	}
+	function _processDefListItems_callback_dd($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
    " . $def . "
    \n";
+	}
+
+
+	function doFencedCodeBlocks($text) {
+	#
+	# Adding the fenced code block syntax to regular Markdown:
+	#
+	# ~~~
+	# Code block
+	# ~~~
+	#
+		$less_than_tab = $this->tab_width;
+
+		$text = preg_replace_callback('{
+				(?:\n|\A)
+				# 1: Opening marker
+				(
+					~{3,} # Marker: three tilde or more.
+				)
+				[ ]* \n # Whitespace and newline following marker.
+
+				# 2: Content
+				(
+					(?>
+						(?!\1 [ ]* \n)	# Not a closing marker.
+						.*\n+
+					)+
+				)
+
+				# Closing marker.
+				\1 [ ]* \n
+			}xm',
+			array(&$this, '_doFencedCodeBlocks_callback'), $text);
+
+		return $text;
+	}
+	function _doFencedCodeBlocks_callback($matches) {
+		$codeblock = $matches[2];
+		$codeblock = htmlspecialchars($codeblock, ENT_NOQUOTES);
+		$codeblock = preg_replace_callback('/^\n+/',
+			array(&$this, '_doFencedCodeBlocks_newlines'), $codeblock);
+		$codeblock = "
    $codeblock
    ";
+		return "\n\n".$this->hashBlock($codeblock)."\n\n";
+	}
+	function _doFencedCodeBlocks_newlines($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.
+	#
+	var $em_relist = array(
+		''  => '(?:(? '(?<=\S)(? '(?<=\S)(? '(?:(? '(?<=\S)(? '(?<=\S)(? '(?:(? '(?<=\S)(? '(?<=\S)(? 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 $text;
+	}
+
+
+	### Footnotes
+
+	function stripFootnotes($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 marker.
+					(?!\n+[ ]{0,3}\S)# ensure line is not blank and followed
+									# by non-indented content
+				)*
+			)
+			}xm',
+			array(&$this, '_stripFootnotes_callback'),
+			$text);
+		return $text;
+	}
+	function _stripFootnotes_callback($matches) {
+		$note_id = $this->fn_id_prefix . $matches[1];
+		$this->footnotes[$note_id] = $this->outdent($matches[2]);
+		return ''; # String that will replace the block
+	}
+
+
+	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 $text;
+	}
+
+
+	function appendFootnotes($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 .= "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]);
+
+				$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);
+
+				# Add backlink to last paragraph; create new paragraph if needed.
+				$backlink = "↩";
+				if (preg_match('{
    $}', $footnote)) {
+					$footnote = substr($footnote, 0, -4) . " $backlink
    ";
+				} else {
+					$footnote .= "\n\n
    $backlink
    ";
+				}
+
+				$text .= "
  • \n";
+				$text .= $footnote . "\n";
+				$text .= "
    • \n\n";
+			}
+
+			$text .= "\n";
+			$text .= "
    ";
+		}
+		return $text;
+	}
+	function _appendFootnotes_callback($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])) {
+			# Transfert footnote content to the ordered list.
+			$this->footnotes_ordered[$node_id] = $this->footnotes[$node_id];
+			unset($this->footnotes[$node_id]);
+
+			$num = $this->footnote_counter++;
+			$attr = " rel=\"footnote\"";
+			if ($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 ###
+
+	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 $text;
+	}
+	function _stripAbbreviations_callback($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($abbr_desc);
+		return ''; # String that will replace the block
+	}
+
+
+	function doAbbreviations($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 $text;
+	}
+	function _doAbbreviations_callback($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];
+		}
+	}
+
+}
+
+
+/*
+
+PHP Markdown Extra
+==================
+
+Description
+-----------
+
+This is a PHP port of the original Markdown formatter written in Perl
+by John Gruber. This special "Extra" version of PHP Markdown features
+further enhancements to the syntax for making additional constructs
+such as tables and definition list.
+
+Markdown is a text-to-HTML filter; it translates an easy-to-read /
+easy-to-write structured text format into HTML. Markdown's text format
+is most similar to that of plain text email, and supports features such
+as headers, *emphasis*, code blocks, blockquotes, and links.
+
+Markdown's syntax is designed not as a generic markup language, but
+specifically to serve as a front-end to (X)HTML. You can use span-level
+HTML tags anywhere in a Markdown document, and you can use block level
+HTML tags (like 
     and  as well).
+
+For more information about Markdown's syntax, see:
+
+
+
+
+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 Markdown actually produced.
+
+
+Version History
+---------------
+
+See the readme file for detailed release notes for this version.
+
+
+Copyright and License
+---------------------
+
+PHP Markdown & Extra
+Copyright (c) 2004-2008 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.
+
+*/
+?>