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<?php
#
# Markdown - A text-to-HTML conversion tool for web writers
#
# PHP Markdown
# Copyright (c) 2004-2015 Michel Fortin
# <https://michelf.ca/projects/php-markdown/>
#
# Original Markdown
# Copyright (c) 2004-2006 John Gruber
# <http://daringfireball.net/projects/markdown/>
#
namespace Michelf;
#
# Markdown Parser Class
#
class Markdown implements MarkdownInterface {
### Version ###
const MARKDOWNLIB_VERSION = "1.5.0";
### 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;
# Optional header id="" generation callback function.
public $header_id_func = null;
# Class attribute to toggle "enhanced ordered list" behaviour
# setting this to true will allow ordered lists to start from the index
# number that is defined first. For example:
# 2. List item two
# 3. List item three
#
# becomes
# <ol start="2">
# <li>List item two</li>
# <li>List item three</li>
# </ol>
public $enhanced_ordered_list = false;
### 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 <p>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('
</\2\s*> # 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.:
# <div>
# <div>
# tags for inner block must be indented.
# </div>
# </div>
#
# 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 `<div>` and stop at the first `</div>`.
$text = preg_replace_callback('{(?>
(?>
(?<=\n) # Starting on its own line
| # or
\A\n? # the at beginning of the doc
)
( # save in $1
# Match from `\n<tag>` to `</tag>\n`, handling nested tags
# in between.
[ ]{0,'.$less_than_tab.'}
<('.$block_tags_b_re.')# start tag = $2
'.$attr.'> # attributes followed by > and \n
'.$content.' # content, support nesting
</\2> # the matching end tag
[ ]* # trailing spaces/tabs
(?=\n+|\Z) # followed by a newline or end of document
| # Special version for tags of group a.
[ ]{0,'.$less_than_tab.'}
<('.$block_tags_a_re.')# start tag = $3
'.$attr.'>[ ]*\n # attributes followed by >
'.$content2.' # content, support nesting
</\3> # the matching end tag
[ ]* # trailing spaces/tabs
(?=\n+|\Z) # followed by a newline or end of document
| # Special case just for <hr />. It was easier to make a special
# case than to make the other regex more complicated.
[ ]{0,'.$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,'.$less_than_tab.'}
(?s:
<!-- .*? -->
)
[ ]*
(?=\n{2,}|\Z) # followed by a blank line or end of document
| # PHP and ASP-style processor instructions (<? and <%)
[ ]{0,'.$less_than_tab.'}
(?s:
<([?%]) # $2
.*?
\2>
)
[ ]*
(?=\n{2,}|\Z) # followed by a blank line or end of document
)
)}Sxmi',
array($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".$this->hashBlock("<hr$this->empty_element_suffix")."\n",
$text);
}
protected $span_gamut = array(
#
# These are all the transformations that occur *within* block-level
# tags like paragraphs, headers, and list items.
#
# Process character escapes, code spans, and inline HTML
# in one shot.
"parseSpan" => -30,
# Process anchor and image tags. Images must come first,
# because ![foo][f] looks like an anchor.
"doImages" => 10,
"doAnchors" => 20,
# Make links out of things like `<http://example.com/>`
# Must come after doAnchors, because you can use < and >
# delimiters in inline links like [this](<url>).
"doAutoLinks" => 30,
"encodeAmpsAndAngles" => 40,
"doItalicsAndBold" => 50,
"doHardBreaks" => 60,
);
protected function runSpanGamut($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 $this->hashPart("<br$this->empty_element_suffix\n");
}
protected function doAnchors($text) {
#
# Turn Markdown link shortcuts into XHTML <a> tags.
#
if ($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);
$result = "<a href=\"$url\"";
if ( isset( $this->titles[$link_id] ) ) {
$title = $this->titles[$link_id];
$title = $this->encodeAttribute($title);
$result .= " title=\"$title\"";
}
$link_text = $this->runSpanGamut($link_text);
$result .= ">$link_text</a>";
$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 <s p a c e s> 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);
$result = "<a href=\"$url\"";
if (isset($title)) {
$title = $this->encodeAttribute($title);
$result .= " title=\"$title\"";
}
$link_text = $this->runSpanGamut($link_text);
$result .= ">$link_text</a>";
return $this->hashPart($result);
}
protected function doImages($text) {
#
# Turn Markdown image shortcuts into <img> 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: 
# 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]);
$result = "<img src=\"$url\" alt=\"$alt_text\"";
if (isset($this->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);
$result = "<img src=\"$url\" alt=\"$alt_text\"";
if (isset($title)) {
$title = $this->encodeAttribute($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;
# id attribute generation
$idAtt = $this->_generateIdFromHeaderValue($matches[1]);
$block = "<h$level$idAtt>".$this->runSpanGamut($matches[1])."</h$level>";
return "\n" . $this->hashBlock($block) . "\n\n";
}
protected function _doHeaders_callback_atx($matches) {
# id attribute generation
$idAtt = $this->_generateIdFromHeaderValue($matches[2]);
$level = strlen($matches[1]);
$block = "<h$level$idAtt>".$this->runSpanGamut($matches[2])."</h$level>";
return "\n" . $this->hashBlock($block) . "\n\n";
}
protected function _generateIdFromHeaderValue($headerValue) {
# if a header_id_func property is set, we can use it to automatically
# generate an id attribute.
#
# This method returns a string in the form id="foo", or an empty string
# otherwise.
if (!is_callable($this->header_id_func)) {
return "";
}
$idValue = call_user_func($this->header_id_func, $headerValue);
if (!$idValue) return "";
return ' id="' . $this->encodeAttribute($idValue) . '"';
}
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)";
$marker_ol_start_re = '[0-9]+';
$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);
$ol_start = 1;
if ($this->enhanced_ordered_list) {
# Get the start number for ordered list.
if ($list_type == 'ol') {
$ol_start_array = array();
$ol_start_check = preg_match("/$marker_ol_start_re/", $matches[4], $ol_start_array);
if ($ol_start_check){
$ol_start = $ol_start_array[0];
}
}
}
if ($ol_start > 1 && $list_type == 'ol'){
$result = $this->hashBlock("<$list_type start=\"$ol_start\">\n" . $result . "</$list_type>");
} else {
$result = $this->hashBlock("<$list_type>\n" . $result . "</$list_type>");
}
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 "<li>" . $item . "</li>\n";
}
protected function doCodeBlocks($text) {
#
# Process Markdown `<pre><code>` 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);
$codeblock = "<pre><code>$codeblock\n</code></pre>";
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 $this->hashPart("<code>$code</code>");
}
protected $em_relist = array(
'' => '(?:(?<!\*)\*(?!\*)|(?<!_)_(?!_))(?![\.,:;]?\s)',
'*' => '(?<![\s*])\*(?!\*)',
'_' => '(?<![\s_])_(?!_)',
);
protected $strong_relist = array(
'' => '(?:(?<!\*)\*\*(?!\*)|(?<!_)__(?!_))(?![\.,:;]?\s)',
'**' => '(?<![\s*])\*\*(?!\*)',
'__' => '(?<![\s_])__(?!_)',
);
protected $em_strong_relist = array(
'' => '(?:(?<!\*)\*\*\*(?!\*)|(?<!_)___(?!_))(?![\.,:;]?\s)',
'***' => '(?<![\s*])\*\*\*(?!\*)',
'___' => '(?<![\s_])___(?!_)',
);
protected $em_strong_prepared_relist;
protected function prepareItalicsAndBold() {
#
# Prepare regular expressions for searching emphasis tokens in any
# context.
#
foreach ($this->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);
$span = "<strong><em>$span</em></strong>";
$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>$span</$tag>";
$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>$span</$tag>";
$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);
$span = "<strong>$span</strong>";
$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);
$span = "<em>$span</em>";
$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 <pre> content,
# so we need to fix that:
$bq = preg_replace_callback('{(\s*<pre>.+?</pre>)}sx',
array($this, '_doBlockQuotes_callback2'), $bq);
return "\n". $this->hashBlock("<blockquote>\n$bq\n</blockquote>")."\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 <p> tags
#
# Strip leading and trailing lines:
$text = preg_replace('/\A\n+|\n+\z/', '', $text);
$grafs = preg_split('/\n{2,}/', $text, -1, PREG_SPLIT_NO_EMPTY);
#
# Wrap <p> tags and unhashify HTML blocks
#
foreach ($grafs as $key => $value) {
if (!preg_match('/^B\x1A[0-9]+B$/', $value)) {
# Is a paragraph.
$value = $this->runSpanGamut($value);
$value = preg_replace('/^([ ]*)/', "<p>", $value);
$value .= "</p>";
$grafs[$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 = <div> tag
// <div \s+
// [^>]*
// \b
// markdown\s*=\s* ([\'"]) # $2 = attr quote char
// 1
// \2
// [^>]*
// >
// )
// ( # $3 = contents
// .*
// )
// (</div>) # $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: <http://bumppo.net/projects/amputator/>
$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: <address@domain.foo>
$text = preg_replace_callback('{
<
(?:mailto:)?
(
(?:
[-!#$%&\'*+/=?^_`.{|}~\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);
$link = "<a href=\"$url\">$text</a>";
return $this->hashPart($link);
}
protected function _doAutoLinks_email_callback($matches) {
$addr = $matches[1];
$url = $this->encodeURLAttribute("mailto:$addr", $text);
$link = "<a href=\"$url\">$text</a>";
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 = "";
$chars = preg_split('/(?<!^)(?!$)/', $text);
$seed = (int)abs(crc32($text) / strlen($text)); # Deterministic seed.
foreach ($chars as $key => $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.'
|
(?<![`\\\\])
`+ # code span marker
'.( $this->no_markup ? '' : '
|
<!-- .*? --> # comment
|
<\?.*?\?> | <%.*?%> # processing instruction
|
<[!$]?[-a-zA-Z0-9:_]+ # regular tags
(?>
\s
(?>[^"\'>]+|"[^"]*"|\'[^\']*\')*
)?
>
|
<[-a-zA-Z0-9:_]+\s*/> # xml-style empty tag
|
</[-a-zA-Z0-9:_]+\s*> # 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]];
}
}