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<?php
#
# Markdown Extra - A text-to-HTML conversion tool for web writers
#
# PHP Markdown Extra
# 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 Extra Parser Class
#
class MarkdownExtra extends \Michelf\Markdown {
### Configuration Variables ###
# Prefix for footnote ids.
public $fn_id_prefix = "";
# Optional title attribute for footnote links and backlinks.
public $fn_link_title = "";
public $fn_backlink_title = "";
# Optional class attribute for footnote links and backlinks.
public $fn_link_class = "footnote-ref";
public $fn_backlink_class = "footnote-backref";
# Class name for table cell alignment (%% replaced left/center/right)
# For instance: 'go-%%' becomes 'go-left' or 'go-right' or 'go-center'
# If empty, the align attribute is used instead of a class name.
public $table_align_class_tmpl = '';
# Optional class prefix for fenced code block.
public $code_class_prefix = "";
# Class attribute for code blocks goes on the `code` tag;
# setting this to true will put attributes on the `pre` tag instead.
public $code_attr_on_pre = false;
# Predefined abbreviations.
public $predef_abbr = array();
### Parser Implementation ###
public function __construct() {
#
# Constructor function. Initialize the parser object.
#
# Add extra escapable characters before parent constructor
# initialize the table.
$this->escape_chars .= ':|';
# Insert extra document, block, and span transformations.
# Parent constructor will do the sorting.
$this->document_gamut += array(
"doFencedCodeBlocks" => 5,
"stripFootnotes" => 15,
"stripAbbreviations" => 25,
"appendFootnotes" => 50,
);
$this->block_gamut += array(
"doFencedCodeBlocks" => 5,
"doTables" => 15,
"doDefLists" => 45,
);
$this->span_gamut += array(
"doFootnotes" => 5,
"doAbbreviations" => 70,
);
$this->enhanced_ordered_list = true;
parent::__construct();
}
# Extra variables used during extra transformations.
protected $footnotes = array();
protected $footnotes_ordered = array();
protected $footnotes_ref_count = array();
protected $footnotes_numbers = array();
protected $abbr_desciptions = array();
protected $abbr_word_re = '';
# Give the current footnote number.
protected $footnote_counter = 1;
protected function setup() {
#
# Setting up Extra-specific variables.
#
parent::setup();
$this->footnotes = array();
$this->footnotes_ordered = array();
$this->footnotes_ref_count = array();
$this->footnotes_numbers = array();
$this->abbr_desciptions = array();
$this->abbr_word_re = '';
$this->footnote_counter = 1;
foreach ($this->predef_abbr as $abbr_word => $abbr_desc) {
if ($this->abbr_word_re)
$this->abbr_word_re .= '|';
$this->abbr_word_re .= preg_quote($abbr_word);
$this->abbr_desciptions[$abbr_word] = trim($abbr_desc);
}
}
protected function teardown() {
#
# Clearing Extra-specific variables.
#
$this->footnotes = array();
$this->footnotes_ordered = array();
$this->footnotes_ref_count = array();
$this->footnotes_numbers = array();
$this->abbr_desciptions = array();
$this->abbr_word_re = '';
parent::teardown();
}
### Extra Attribute Parser ###
# Expression to use to catch attributes (includes the braces)
protected $id_class_attr_catch_re = '\{((?:[ ]*[#.a-z][-_:a-zA-Z0-9=]+){1,})[ ]*\}';
# Expression to use when parsing in a context when no capture is desired
protected $id_class_attr_nocatch_re = '\{(?:[ ]*[#.a-z][-_:a-zA-Z0-9=]+){1,}[ ]*\}';
protected function doExtraAttributes($tag_name, $attr, $defaultIdValue = null) {
#
# Parse attributes caught by the $this->id_class_attr_catch_re expression
# and return the HTML-formatted list of attributes.
#
# Currently supported attributes are .class and #id.
#
# In addition, this method also supports supplying a default Id value,
# which will be used to populate the id attribute in case it was not
# overridden.
if (empty($attr) && !$defaultIdValue) return "";
# Split on components
preg_match_all('/[#.a-z][-_:a-zA-Z0-9=]+/', $attr, $matches);
$elements = $matches[0];
# handle classes and ids (only first id taken into account)
$classes = array();
$attributes = array();
$id = false;
foreach ($elements as $element) {
if ($element{0} == '.') {
$classes[] = substr($element, 1);
} else if ($element{0} == '#') {
if ($id === false) $id = substr($element, 1);
} else if (strpos($element, '=') > 0) {
$parts = explode('=', $element, 2);
$attributes[] = $parts[0] . '="' . $parts[1] . '"';
}
}
if (!$id) $id = $defaultIdValue;
# compose attributes as string
$attr_str = "";
if (!empty($id)) {
$attr_str .= ' id="'.$this->encodeAttribute($id) .'"';
}
if (!empty($classes)) {
$attr_str .= ' class="'. implode(" ", $classes) . '"';
}
if (!$this->no_markup && !empty($attributes)) {
$attr_str .= ' '.implode(" ", $attributes);
}
return $attr_str;
}
protected function stripLinkDefinitions($text) {
#
# Strips link definitions from text, stores the URLs and titles in
# hash references.
#
$less_than_tab = $this->tab_width - 1;
# Link defs are in the form: ^[id]: url "optional title"
$text = preg_replace_callback('{
^[ ]{0,'.$less_than_tab.'}\[(.+)\][ ]?: # id = $1
[ ]*
\n? # maybe *one* newline
[ ]*
(?:
<(.+?)> # url = $2
|
(\S+?) # url = $3
)
[ ]*
\n? # maybe one newline
[ ]*
(?:
(?<=\s) # lookbehind for whitespace
["(]
(.*?) # title = $4
[")]
[ ]*
)? # title is optional
(?:[ ]* '.$this->id_class_attr_catch_re.' )? # $5 = extra id & class attr
(?:\n+|\Z)
}xm',
array($this, '_stripLinkDefinitions_callback'),
$text);
return $text;
}
protected function _stripLinkDefinitions_callback($matches) {
$link_id = strtolower($matches[1]);
$url = $matches[2] == '' ? $matches[3] : $matches[2];
$this->urls[$link_id] = $url;
$this->titles[$link_id] =& $matches[4];
$this->ref_attr[$link_id] = $this->doExtraAttributes("", $dummy =& $matches[5]);
return ''; # String that will replace the block
}
### HTML Block Parser ###
# Tags that are always treated as block tags:
protected $block_tags_re = 'p|div|h[1-6]|blockquote|pre|table|dl|ol|ul|address|form|fieldset|iframe|hr|legend|article|section|nav|aside|hgroup|header|footer|figcaption|figure';
# Tags treated as block tags only if the opening tag is alone on its line:
protected $context_block_tags_re = 'script|noscript|style|ins|del|iframe|object|source|track|param|math|svg|canvas|audio|video';
# Tags where markdown="1" default to span mode:
protected $contain_span_tags_re = 'p|h[1-6]|li|dd|dt|td|th|legend|address';
# Tags which must not have their contents modified, no matter where
# they appear:
protected $clean_tags_re = 'script|style|math|svg';
# Tags that do not need to be closed.
protected $auto_close_tags_re = 'hr|img|param|source|track';
protected function hashHTMLBlocks($text) {
#
# Hashify HTML Blocks and "clean tags".
#
# We only want to do this for block-level HTML tags, such as headers,
# lists, and tables. That's because we still want to wrap <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.
#
# This works by calling _HashHTMLBlocks_InMarkdown, which then calls
# _HashHTMLBlocks_InHTML when it encounter block tags. When the markdown="1"
# attribute is found within a tag, _HashHTMLBlocks_InHTML calls back
# _HashHTMLBlocks_InMarkdown to handle the Markdown syntax within the tag.
# These two functions are calling each other. It's recursive!
#
if ($this->no_markup) return $text;
#
# Call the HTML-in-Markdown hasher.
#
list($text, ) = $this->_hashHTMLBlocks_inMarkdown($text);
return $text;
}
protected function _hashHTMLBlocks_inMarkdown($text, $indent = 0,
$enclosing_tag_re = '', $span = false)
{
#
# Parse markdown text, calling _HashHTMLBlocks_InHTML for block tags.
#
# * $indent is the number of space to be ignored when checking for code
# blocks. This is important because if we don't take the indent into
# account, something like this (which looks right) won't work as expected:
#
# <div>
# <div markdown="1">
# Hello World. <-- Is this a Markdown code block or text?
# </div> <-- Is this a Markdown code block or a real tag?
# <div>
#
# If you don't like this, just don't indent the tag on which
# you apply the markdown="1" attribute.
#
# * If $enclosing_tag_re is not empty, stops at the first unmatched closing
# tag with that name. Nested tags supported.
#
# * If $span is true, text inside must treated as span. So any double
# newline will be replaced by a single newline so that it does not create
# paragraphs.
#
# Returns an array of that form: ( processed text , remaining text )
#
if ($text === '') return array('', '');
# Regex to check for the presense of newlines around a block tag.
$newline_before_re = '/(?:^\n?|\n\n)*$/';
$newline_after_re =
'{
^ # Start of text following the tag.
(?>[ ]*<!--.*?-->)? # Optional comment.
[ ]*\n # Must be followed by newline.
}xs';
# Regex to match any tag.
$block_tag_re =
'{
( # $2: Capture whole tag.
</? # Any opening or closing tag.
(?> # Tag name.
'.$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\[.*?\]\]> # CData Block
'. ( !$span ? ' # If not in span.
|
# Indented code block
(?: ^[ ]*\n | ^ | \n[ ]*\n )
[ ]{'.($indent+4).'}[^\n]* \n
(?>
(?: [ ]{'.($indent+4).'}[^\n]* | [ ]* ) \n
)*
|
# Fenced code block marker
(?<= ^ | \n )
[ ]{0,'.($indent+3).'}(?:~{3,}|`{3,})
[ ]*
(?:
\.?[-_:a-zA-Z0-9]+ # standalone class name
|
'.$this->id_class_attr_nocatch_re.' # extra attributes
)?
[ ]*
(?= \n )
' : '' ). ' # End (if not is span).
|
# Code span marker
# Note, this regex needs to go after backtick fenced
# code blocks but it should also be kept outside of the
# "if not in span" condition adding backticks to the parser
`+
)
}xs';
$depth = 0; # Current depth inside the tag tree.
$parsed = ""; # Parsed text that will be returned.
#
# Loop through every tag until we find the closing tag of the parent
# or loop until reaching the end of text if no parent tag specified.
#
do {
#
# Split the text using the first $tag_match pattern found.
# Text before pattern will be first in the array, text after
# pattern will be at the end, and between will be any catches made
# by the pattern.
#
$parts = preg_split($block_tag_re, $text, 2,
PREG_SPLIT_DELIM_CAPTURE);
# If in Markdown span mode, add a empty-string span-level hash
# after each newline to prevent triggering any block element.
if ($span) {
$void = $this->hashPart("", ':');
$newline = "$void\n";
$parts[0] = $void . str_replace("\n", $newline, $parts[0]) . $void;
}
$parsed .= $parts[0]; # Text before current tag.
# If end of $text has been reached. Stop loop.
if (count($parts) < 3) {
$text = "";
break;
}
$tag = $parts[1]; # Tag to handle.
$text = $parts[2]; # Remaining text after current tag.
$tag_re = preg_quote($tag); # For use in a regular expression.
#
# Check for: Fenced code block marker.
# Note: need to recheck the whole tag to disambiguate backtick
# fences from code spans
#
if (preg_match('{^\n?([ ]{0,'.($indent+3).'})(~{3,}|`{3,})[ ]*(?:\.?[-_:a-zA-Z0-9]+|'.$this->id_class_attr_nocatch_re.')?[ ]*\n?$}', $tag, $capture)) {
# Fenced code block marker: find matching end marker.
$fence_indent = strlen($capture[1]); # use captured indent in re
$fence_re = $capture[2]; # use captured fence in re
if (preg_match('{^(?>.*\n)*?[ ]{'.($fence_indent).'}'.$fence_re.'[ ]*(?:\n|$)}', $text,
$matches))
{
# End marker found: pass text unchanged until marker.
$parsed .= $tag . $matches[0];
$text = substr($text, strlen($matches[0]));
}
else {
# No end marker: just skip it.
$parsed .= $tag;
}
}
#
# Check for: Indented code block.
#
else if ($tag{0} == "\n" || $tag{0} == " ") {
# Indented code block: pass it unchanged, will be handled
# later.
$parsed .= $tag;
}
#
# Check for: Code span marker
# Note: need to check this after backtick fenced code blocks
#
else if ($tag{0} == "`") {
# Find corresponding end marker.
$tag_re = preg_quote($tag);
if (preg_match('{^(?>.+?|\n(?!\n))*?(?<!`)'.$tag_re.'(?!`)}',
$text, $matches))
{
# End marker found: pass text unchanged until marker.
$parsed .= $tag . $matches[0];
$text = substr($text, strlen($matches[0]));
}
else {
# Unmatched 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('{^</?(?:'.$enclosing_tag_re.')\b}', $tag))
{
#
# Increase/decrease nested tag count.
#
if ($tag{1} == '/') $depth--;
else if ($tag{strlen($tag)-2} != '/') $depth++;
if ($depth < 0) {
#
# Going out of parent element. Clean up and break so we
# return to the calling function.
#
$text = $tag . $text;
break;
}
$parsed .= $tag;
}
else {
$parsed .= $tag;
}
} while ($depth >= 0);
return array($parsed, $text);
}
protected function _hashHTMLBlocks_inHTML($text, $hash_method, $md_attr) {
#
# Parse HTML, calling _HashHTMLBlocks_InMarkdown for block tags.
#
# * Calls $hash_method to convert any blocks.
# * Stops when the first opening tag closes.
# * $md_attr indicate if the use of the `markdown="1"` attribute is allowed.
# (it is not inside clean tags)
#
# Returns an array of that form: ( processed text , remaining text )
#
if ($text === '') return array('', '');
# Regex to match `markdown` attribute inside of a tag.
$markdown_attr_re = '
{
\s* # Eat whitespace before the `markdown` attribute
markdown
\s*=\s*
(?>
(["\']) # $1: quote delimiter
(.*?) # $2: attribute value
\1 # matching delimiter
|
([^\s>]*) # $3: unquoted attribute value
)
() # $4: make $3 always defined (avoid warnings)
}xs';
# Regex to match any tag.
$tag_re = '{
( # $2: Capture whole tag.
</? # Any opening or closing tag.
[\w:$]+ # Tag name.
(?:
(?=[\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\[.*?\]\]> # 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 = $parts[2]; # Remaining text after current tag.
#
# Check for: Auto-close tag (like <hr/>)
# Comments and Processing Instructions.
#
if (preg_match('{^</?(?:'.$this->auto_close_tags_re.')\b}', $tag) ||
$tag{1} == '!' || $tag{1} == '?')
{
# Just add the tag to the block as if it was text.
$block_text .= $tag;
}
else {
#
# Increase/decrease nested tag count. Only do so if
# the tag's name match base tag's.
#
if (preg_match('{^</?'.$base_tag_name_re.'\b}', $tag)) {
if ($tag{1} == '/') $depth--;
else if ($tag{strlen($tag)-2} != '/') $depth++;
}
#
# Check for `markdown="1"` attribute and handle it.
#
if ($md_attr &&
preg_match($markdown_attr_re, $tag, $attr_m) &&
preg_match('/^1|block|span$/', $attr_m[2] . $attr_m[3]))
{
# Remove `markdown` attribute from opening tag.
$tag = preg_replace($markdown_attr_re, '', $tag);
# Check if text inside this tag must be parsed in span mode.
$this->mode = $attr_m[2] . $attr_m[3];
$span_mode = $this->mode == 'span' || $this->mode != 'block' &&
preg_match('{^<(?:'.$this->contain_span_tags_re.')\b}', $tag);
# Calculate indent before tag.
if (preg_match('/(?:^|\n)( *?)(?! ).*?$/', $block_text, $matches)) {
$strlen = $this->utf8_strlen;
$indent = $strlen($matches[1], 'UTF-8');
} else {
$indent = 0;
}
# End preceding block with this tag.
$block_text .= $tag;
$parsed .= $this->$hash_method($block_text);
# Get enclosing tag name for the ParseMarkdown function.
# (This pattern makes $tag_name_re safe without quoting.)
preg_match('/^<([\w:$]*)\b/', $tag, $matches);
$tag_name_re = $matches[1];
# Parse the content using the HTML-in-Markdown parser.
list ($block_text, $text)
= $this->_hashHTMLBlocks_inMarkdown($text, $indent,
$tag_name_re, $span_mode);
# Outdent markdown text.
if ($indent > 0) {
$block_text = preg_replace("/^[ ]{1,$indent}/m", "",
$block_text);
}
# Append tag content to parsed text.
if (!$span_mode) $parsed .= "\n\n$block_text\n\n";
else $parsed .= "$block_text";
# Start over with a new block.
$block_text = "";
}
else $block_text .= $tag;
}
} while ($depth > 0);
#
# Hash last block text that wasn't processed inside the loop.
#
$parsed .= $this->$hash_method($block_text);
return array($parsed, $text);
}
protected function hashClean($text) {
#
# Called whenever a tag must be hashed when a function inserts a "clean" tag
# in $text, it passes through this function and is automaticaly escaped,
# blocking invalid nested overlap.
#
return $this->hashPart($text, 'C');
}
protected function doAnchors($text) {
#
# Turn Markdown link shortcuts into XHTML <a> tags.
#
if ($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
\[
('.$this->nested_brackets_re.') # link text = $2
\]
\( # literal paren
[ \n]*
(?:
<(.+?)> # href = $3
|
('.$this->nested_url_parenthesis_re.') # href = $4
)
[ \n]*
( # $5
([\'"]) # quote char = $6
(.*?) # Title = $7
\6 # matching quote
[ \n]* # ignore any spaces/tabs between closing quote and )
)? # title is optional
\)
(?:[ ]? '.$this->id_class_attr_catch_re.' )? # $8 = id/class attributes
)
}xs',
array($this, '_doAnchors_inline_callback'), $text);
#
# Last, handle reference-style shortcuts: [link text]
# These must come last in case you've also got [link text][1]
# or [link text](/foo)
#
$text = preg_replace_callback('{
( # wrap whole match in $1
\[
([^\[\]]+) # link text = $2; can\'t contain [ or ]
\]
)
}xs',
array($this, '_doAnchors_reference_callback'), $text);
$this->in_anchor = false;
return $text;
}
protected function _doAnchors_reference_callback($matches) {
$whole_match = $matches[1];
$link_text = $matches[2];
$link_id =& $matches[3];
if ($link_id == "") {
# for shortcut links like [this][] or [this].
$link_id = $link_text;
}
# lower-case and turn embedded newlines into spaces
$link_id = strtolower($link_id);
$link_id = preg_replace('{[ ]?\n}', ' ', $link_id);
if (isset($this->urls[$link_id])) {
$url = $this->urls[$link_id];
$url = $this->encodeURLAttribute($url);
$result = "<a href=\"$url\"";
if ( isset( $this->titles[$link_id] ) ) {
$title = $this->titles[$link_id];
$title = $this->encodeAttribute($title);
$result .= " title=\"$title\"";
}
if (isset($this->ref_attr[$link_id]))
$result .= $this->ref_attr[$link_id];
$link_text = $this->runSpanGamut($link_text);
$result .= ">$link_text</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];
$attr = $this->doExtraAttributes("a", $dummy =& $matches[8]);
// 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\"";
}
$result .= $attr;
$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
\( # literal paren
[ \n]*
(?:
<(\S*)> # src url = $3
|
('.$this->nested_url_parenthesis_re.') # src url = $4
)
[ \n]*
( # $5
([\'"]) # quote char = $6
(.*?) # title = $7
\6 # matching quote
[ \n]*
)? # title is optional
\)
(?:[ ]? '.$this->id_class_attr_catch_re.' )? # $8 = id/class attributes
)
}xs',
array($this, '_doImages_inline_callback'), $text);
return $text;
}
protected function _doImages_reference_callback($matches) {
$whole_match = $matches[1];
$alt_text = $matches[2];
$link_id = strtolower($matches[3]);
if ($link_id == "") {
$link_id = strtolower($alt_text); # for shortcut links like ![this][].
}
$alt_text = $this->encodeAttribute($alt_text);
if (isset($this->urls[$link_id])) {
$url = $this->encodeURLAttribute($this->urls[$link_id]);
$result = "<img src=\"$url\" alt=\"$alt_text\"";
if (isset($this->titles[$link_id])) {
$title = $this->titles[$link_id];
$title = $this->encodeAttribute($title);
$result .= " title=\"$title\"";
}
if (isset($this->ref_attr[$link_id]))
$result .= $this->ref_attr[$link_id];
$result .= $this->empty_element_suffix;
$result = $this->hashPart($result);
}
else {
# If there's no such link ID, leave intact:
$result = $whole_match;
}
return $result;
}
protected function _doImages_inline_callback($matches) {
$whole_match = $matches[1];
$alt_text = $matches[2];
$url = $matches[3] == '' ? $matches[4] : $matches[3];
$title =& $matches[7];
$attr = $this->doExtraAttributes("img", $dummy =& $matches[8]);
$alt_text = $this->encodeAttribute($alt_text);
$url = $this->encodeURLAttribute($url);
$result = "<img src=\"$url\" alt=\"$alt_text\"";
if (isset($title)) {
$title = $this->encodeAttribute($title);
$result .= " title=\"$title\""; # $title already quoted
}
$result .= $attr;
$result .= $this->empty_element_suffix;
return $this->hashPart($result);
}
protected function doHeaders($text) {
#
# Redefined to add id and class attribute support.
#
# Setext-style headers:
# Header 1 {#header1}
# ========
#
# Header 2 {#header2 .class1 .class2}
# --------
#
$text = preg_replace_callback(
'{
(^.+?) # $1: Header text
(?:[ ]+ '.$this->id_class_attr_catch_re.' )? # $3 = id/class attributes
[ ]*\n(=+|-+)[ ]*\n+ # $3: Header footer
}mx',
array($this, '_doHeaders_callback_setext'), $text);
# atx-style headers:
# # Header 1 {#header1}
# ## Header 2 {#header2}
# ## Header 2 with closing hashes ## {#header3.class1.class2}
# ...
# ###### Header 6 {.class2}
#
$text = preg_replace_callback('{
^(\#{1,6}) # $1 = string of #\'s
[ ]*
(.+?) # $2 = Header text
[ ]*
\#* # optional closing #\'s (not counted)
(?:[ ]+ '.$this->id_class_attr_catch_re.' )? # $3 = id/class attributes
[ ]*
\n+
}xm',
array($this, '_doHeaders_callback_atx'), $text);
return $text;
}
protected function _doHeaders_callback_setext($matches) {
if ($matches[3] == '-' && preg_match('{^- }', $matches[1]))
return $matches[0];
$level = $matches[3]{0} == '=' ? 1 : 2;
$defaultId = is_callable($this->header_id_func) ? call_user_func($this->header_id_func, $matches[1]) : null;
$attr = $this->doExtraAttributes("h$level", $dummy =& $matches[2], $defaultId);
$block = "<h$level$attr>".$this->runSpanGamut($matches[1])."</h$level>";
return "\n" . $this->hashBlock($block) . "\n\n";
}
protected function _doHeaders_callback_atx($matches) {
$level = strlen($matches[1]);
$defaultId = is_callable($this->header_id_func) ? call_user_func($this->header_id_func, $matches[2]) : null;
$attr = $this->doExtraAttributes("h$level", $dummy =& $matches[3], $defaultId);
$block = "<h$level$attr>".$this->runSpanGamut($matches[2])."</h$level>";
return "\n" . $this->hashBlock($block) . "\n\n";
}
protected function doTables($text) {
#
# Form HTML tables.
#
$less_than_tab = $this->tab_width - 1;
#
# Find tables with leading pipe.
#
# | Header 1 | Header 2
# | -------- | --------
# | Cell 1 | Cell 2
# | Cell 3 | Cell 4
#
$text = preg_replace_callback('
{
^ # Start of a line
[ ]{0,'.$less_than_tab.'} # Allowed whitespace.
[|] # Optional leading pipe (present)
(.+) \n # $1: Header row (at least one pipe)
[ ]{0,'.$less_than_tab.'} # Allowed whitespace.
[|] ([ ]*[-:]+[-| :]*) \n # $2: Header underline
( # $3: Cells
(?>
[ ]* # Allowed whitespace.
[|] .* \n # Row content.
)*
)
(?=\n|\Z) # Stop at final double newline.
}xm',
array($this, '_doTable_leadingPipe_callback'), $text);
#
# Find tables without leading pipe.
#
# Header 1 | Header 2
# -------- | --------
# Cell 1 | Cell 2
# Cell 3 | Cell 4
#
$text = preg_replace_callback('
{
^ # Start of a line
[ ]{0,'.$less_than_tab.'} # Allowed whitespace.
(\S.*[|].*) \n # $1: Header row (at least one pipe)
[ ]{0,'.$less_than_tab.'} # Allowed whitespace.
([-:]+[ ]*[|][-| :]*) \n # $2: Header underline
( # $3: Cells
(?>
.* [|] .* \n # Row content
)*
)
(?=\n|\Z) # Stop at final double newline.
}xm',
array($this, '_DoTable_callback'), $text);
return $text;
}
protected function _doTable_leadingPipe_callback($matches) {
$head = $matches[1];
$underline = $matches[2];
$content = $matches[3];
# Remove leading pipe for each row.
$content = preg_replace('/^ *[|]/m', '', $content);
return $this->_doTable_callback(array($matches[0], $head, $underline, $content));
}
protected function _doTable_makeAlignAttr($alignname)
{
if (empty($this->table_align_class_tmpl))
return " align=\"$alignname\"";
$classname = str_replace('%%', $alignname, $this->table_align_class_tmpl);
return " class=\"$classname\"";
}
protected function _doTable_callback($matches) {
$head = $matches[1];
$underline = $matches[2];
$content = $matches[3];
# Remove any tailing pipes for each line.
$head = preg_replace('/[|] *$/m', '', $head);
$underline = preg_replace('/[|] *$/m', '', $underline);
$content = preg_replace('/[|] *$/m', '', $content);
# Reading alignement from header underline.
$separators = preg_split('/ *[|] */', $underline);
foreach ($separators as $n => $s) {
if (preg_match('/^ *-+: *$/', $s))
$attr[$n] = $this->_doTable_makeAlignAttr('right');
else if (preg_match('/^ *:-+: *$/', $s))
$attr[$n] = $this->_doTable_makeAlignAttr('center');
else if (preg_match('/^ *:-+ *$/', $s))
$attr[$n] = $this->_doTable_makeAlignAttr('left');
else
$attr[$n] = '';
}
# Parsing span elements, including code spans, character escapes,
# and inline HTML tags, so that pipes inside those gets ignored.
$head = $this->parseSpan($head);
$headers = preg_split('/ *[|] */', $head);
$col_count = count($headers);
$attr = array_pad($attr, $col_count, '');
# Write column headers.
$text = "<table>\n";
$text .= "<thead>\n";
$text .= "<tr>\n";
foreach ($headers as $n => $header)
$text .= " <th$attr[$n]>".$this->runSpanGamut(trim($header))."</th>\n";
$text .= "</tr>\n";
$text .= "</thead>\n";
# Split content by row.
$rows = explode("\n", trim($content, "\n"));
$text .= "<tbody>\n";
foreach ($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, '');
$text .= "<tr>\n";
foreach ($row_cells as $n => $cell)
$text .= " <td$attr[$n]>".$this->runSpanGamut(trim($cell))."</td>\n";
$text .= "</tr>\n";
}
$text .= "</tbody>\n";
$text .= "</table>";
return $this->hashBlock($text) . "\n";
}
protected function doDefLists($text) {
#
# Form HTML definition lists.
#
$less_than_tab = $this->tab_width - 1;
# Re-usable pattern to match any entire dl list:
$whole_list_re = '(?>
( # $1 = whole list
( # $2
[ ]{0,'.$less_than_tab.'}
((?>.*\S.*\n)+) # $3 = defined term
\n?
[ ]{0,'.$less_than_tab.'}:[ ]+ # colon starting definition
)
(?s:.+?)
( # $4
\z
|
\n{2,}
(?=\S)
(?! # Negative lookahead for another term
[ ]{0,'.$less_than_tab.'}
(?: \S.*\n )+? # defined term
\n?
[ ]{0,'.$less_than_tab.'}:[ ]+ # colon starting definition
)
(?! # Negative lookahead for another definition
[ ]{0,'.$less_than_tab.'}:[ ]+ # colon starting definition
)
)
)
)'; // mx
$text = preg_replace_callback('{
(?>\A\n?|(?<=\n\n))
'.$whole_list_re.'
}mx',
array($this, '_doDefLists_callback'), $text);
return $text;
}
protected function _doDefLists_callback($matches) {
# Re-usable patterns to match list item bullets and number markers:
$list = $matches[1];
# Turn double returns into triple returns, so that we can make a
# paragraph for the last item in a list, if necessary:
$result = trim($this->processDefListItems($list));
$result = "<dl>\n" . $result . "\n</dl>";
return $this->hashBlock($result) . "\n\n";
}
protected function processDefListItems($list_str) {
#
# Process the contents of a single definition list, splitting it
# into individual term and definition list items.
#
$less_than_tab = $this->tab_width - 1;
# trim trailing blank lines:
$list_str = preg_replace("/\n{2,}\\z/", "\n", $list_str);
# Process definition terms.
$list_str = preg_replace_callback('{
(?>\A\n?|\n\n+) # leading line
( # definition terms = $1
[ ]{0,'.$less_than_tab.'} # leading whitespace
(?!\:[ ]|[ ]) # negative lookahead for a definition
# mark (colon) or more whitespace.
(?> \S.* \n)+? # actual term (not whitespace).
)
(?=\n?[ ]{0,3}:[ ]) # lookahead for following line feed
# with a definition mark.
}xm',
array($this, '_processDefListItems_callback_dt'), $list_str);
# Process actual definitions.
$list_str = preg_replace_callback('{
\n(\n+)? # leading line = $1
( # marker space = $2
[ ]{0,'.$less_than_tab.'} # whitespace before colon
\:[ ]+ # definition mark (colon)
)
((?s:.+?)) # definition text = $3
(?= \n+ # stop at next definition mark,
(?: # next term or end of text
[ ]{0,'.$less_than_tab.'} \:[ ] |
<dt> | \z
)
)
}xm',
array($this, '_processDefListItems_callback_dd'), $list_str);
return $list_str;
}
protected function _processDefListItems_callback_dt($matches) {
$terms = explode("\n", trim($matches[1]));
$text = '';
foreach ($terms as $term) {
$term = $this->runSpanGamut(trim($term));
$text .= "\n<dt>" . $term . "</dt>";
}
return $text . "\n";
}
protected function _processDefListItems_callback_dd($matches) {
$leading_line = $matches[1];
$marker_space = $matches[2];
$def = $matches[3];
if ($leading_line || preg_match('/\n{2,}/', $def)) {
# Replace marker with the appropriate whitespace indentation
$def = str_repeat(' ', strlen($marker_space)) . $def;
$def = $this->runBlockGamut($this->outdent($def . "\n\n"));
$def = "\n". $def ."\n";
}
else {
$def = rtrim($def);
$def = $this->runSpanGamut($this->outdent($def));
}
return "\n<dd>" . $def . "</dd>\n";
}
protected function doFencedCodeBlocks($text) {
#
# Adding the fenced code block syntax to regular Markdown:
#
# ~~~
# Code block
# ~~~
#
$less_than_tab = $this->tab_width;
$text = preg_replace_callback('{
(?:\n|\A)
# 1: Opening marker
(
(?:~{3,}|`{3,}) # 3 or more tildes/backticks.
)
[ ]*
(?:
\.?([-_:a-zA-Z0-9]+) # 2: standalone class name
|
'.$this->id_class_attr_catch_re.' # 3: Extra attributes
)?
[ ]* \n # Whitespace and newline following marker.
# 4: Content
(
(?>
(?!\1 [ ]* \n) # Not a closing marker.
.*\n+
)+
)
# Closing marker.
\1 [ ]* (?= \n )
}xm',
array($this, '_doFencedCodeBlocks_callback'), $text);
return $text;
}
protected function _doFencedCodeBlocks_callback($matches) {
$classname =& $matches[2];
$attrs =& $matches[3];
$codeblock = $matches[4];
$codeblock = htmlspecialchars($codeblock, ENT_NOQUOTES);
$codeblock = preg_replace_callback('/^\n+/',
array($this, '_doFencedCodeBlocks_newlines'), $codeblock);
if ($classname != "") {
if ($classname{0} == '.')
$classname = substr($classname, 1);
$attr_str = ' class="'.$this->code_class_prefix.$classname.'"';
} else {
$attr_str = $this->doExtraAttributes($this->code_attr_on_pre ? "pre" : "code", $attrs);
}
$pre_attr_str = $this->code_attr_on_pre ? $attr_str : '';
$code_attr_str = $this->code_attr_on_pre ? '' : $attr_str;
$codeblock = "<pre$pre_attr_str><code$code_attr_str>$codeblock</code></pre>";
return "\n\n".$this->hashBlock($codeblock)."\n\n";
}
protected function _doFencedCodeBlocks_newlines($matches) {
return str_repeat("<br$this->empty_element_suffix",
strlen($matches[0]));
}
#
# Redefining emphasis markers so that emphasis by underscore does not
# work in the middle of a word.
#
protected $em_relist = array(
'' => '(?:(?<!\*)\*(?!\*)|(?<![a-zA-Z0-9_])_(?!_))(?![\.,:;]?\s)',
'*' => '(?<![\s*])\*(?!\*)',
'_' => '(?<![\s_])_(?![a-zA-Z0-9_])',
);
protected $strong_relist = array(
'' => '(?:(?<!\*)\*\*(?!\*)|(?<![a-zA-Z0-9_])__(?!_))(?![\.,:;]?\s)',
'**' => '(?<![\s*])\*\*(?!\*)',
'__' => '(?<![\s_])__(?![a-zA-Z0-9_])',
);
protected $em_strong_relist = array(
'' => '(?:(?<!\*)\*\*\*(?!\*)|(?<![a-zA-Z0-9_])___(?!_))(?![\.,:;]?\s)',
'***' => '(?<![\s*])\*\*\*(?!\*)',
'___' => '(?<![\s_])___(?![a-zA-Z0-9_])',
);
protected function formParagraphs($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) {
$value = trim($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) {
$value = "<p>$value</p>";
}
$grafs[$key] = $value;
}
# Join grafs in one text, then unhash HTML tags.
$text = implode("\n\n", $grafs);
# Finish by removing any tag hashes still present in $text.
$text = $this->unhash($text);
return $text;
}
### Footnotes
protected function stripFootnotes($text) {
#
# Strips link definitions from text, stores the URLs and titles in
# hash references.
#
$less_than_tab = $this->tab_width - 1;
# Link defs are in the form: [^id]: url "optional title"
$text = preg_replace_callback('{
^[ ]{0,'.$less_than_tab.'}\[\^(.+?)\][ ]?: # note_id = $1
[ ]*
\n? # maybe *one* newline
( # text = $2 (no blank lines allowed)
(?:
.+ # actual text
|
\n # newlines but
(?!\[.+?\][ ]?:\s)# negative lookahead for footnote or link definition marker.
(?!\n+[ ]{0,3}\S)# ensure line is not blank and followed
# by non-indented content
)*
)
}xm',
array($this, '_stripFootnotes_callback'),
$text);
return $text;
}
protected function _stripFootnotes_callback($matches) {
$note_id = $this->fn_id_prefix . $matches[1];
$this->footnotes[$note_id] = $this->outdent($matches[2]);
return ''; # String that will replace the block
}
protected function doFootnotes($text) {
#
# Replace footnote references in $text [^id] with a special text-token
# which will be replaced by the actual footnote marker in appendFootnotes.
#
if (!$this->in_anchor) {
$text = preg_replace('{\[\^(.+?)\]}', "F\x1Afn:\\1\x1A:", $text);
}
return $text;
}
protected function appendFootnotes($text) {
#
# Append footnote list to text.
#
$text = preg_replace_callback('{F\x1Afn:(.*?)\x1A:}',
array($this, '_appendFootnotes_callback'), $text);
if (!empty($this->footnotes_ordered)) {
$text .= "\n\n";
$text .= "<div class=\"footnotes\">\n";
$text .= "<hr". $this->empty_element_suffix ."\n";
$text .= "<ol>\n\n";
$attr = "";
if ($this->fn_backlink_class != "") {
$class = $this->fn_backlink_class;
$class = $this->encodeAttribute($class);
$attr .= " class=\"$class\"";
}
if ($this->fn_backlink_title != "") {
$title = $this->fn_backlink_title;
$title = $this->encodeAttribute($title);
$attr .= " title=\"$title\"";
}
$num = 0;
while (!empty($this->footnotes_ordered)) {
$footnote = reset($this->footnotes_ordered);
$note_id = key($this->footnotes_ordered);
unset($this->footnotes_ordered[$note_id]);
$ref_count = $this->footnotes_ref_count[$note_id];
unset($this->footnotes_ref_count[$note_id]);
unset($this->footnotes[$note_id]);
$footnote .= "\n"; # Need to append newline before parsing.
$footnote = $this->runBlockGamut("$footnote\n");
$footnote = preg_replace_callback('{F\x1Afn:(.*?)\x1A:}',
array($this, '_appendFootnotes_callback'), $footnote);
$attr = str_replace("%%", ++$num, $attr);
$note_id = $this->encodeAttribute($note_id);
# Prepare backlink, multiple backlinks if multiple references
$backlink = "<a href=\"#fnref:$note_id\"$attr>↩</a>";
for ($ref_num = 2; $ref_num <= $ref_count; ++$ref_num) {
$backlink .= " <a href=\"#fnref$ref_num:$note_id\"$attr>↩</a>";
}
# Add backlink to last paragraph; create new paragraph if needed.
if (preg_match('{</p>$}', $footnote)) {
$footnote = substr($footnote, 0, -4) . " $backlink</p>";
} else {
$footnote .= "\n\n<p>$backlink</p>";
}
$text .= "<li id=\"fn:$note_id\">\n";
$text .= $footnote . "\n";
$text .= "</li>\n\n";
}
$text .= "</ol>\n";
$text .= "</div>";
}
return $text;
}
protected function _appendFootnotes_callback($matches) {
$node_id = $this->fn_id_prefix . $matches[1];
# Create footnote marker only if it has a corresponding footnote *and*
# the footnote hasn't been used by another marker.
if (isset($this->footnotes[$node_id])) {
$num =& $this->footnotes_numbers[$node_id];
if (!isset($num)) {
# Transfer footnote content to the ordered list and give it its
# number
$this->footnotes_ordered[$node_id] = $this->footnotes[$node_id];
$this->footnotes_ref_count[$node_id] = 1;
$num = $this->footnote_counter++;
$ref_count_mark = '';
} else {
$ref_count_mark = $this->footnotes_ref_count[$node_id] += 1;
}
$attr = "";
if ($this->fn_link_class != "") {
$class = $this->fn_link_class;
$class = $this->encodeAttribute($class);
$attr .= " class=\"$class\"";
}
if ($this->fn_link_title != "") {
$title = $this->fn_link_title;
$title = $this->encodeAttribute($title);
$attr .= " title=\"$title\"";
}
$attr = str_replace("%%", $num, $attr);
$node_id = $this->encodeAttribute($node_id);
return
"<sup id=\"fnref$ref_count_mark:$node_id\">".
"<a href=\"#fn:$node_id\"$attr>$num</a>".
"</sup>";
}
return "[^".$matches[1]."]";
}
### Abbreviations ###
protected function stripAbbreviations($text) {
#
# Strips abbreviations from text, stores titles in hash references.
#
$less_than_tab = $this->tab_width - 1;
# Link defs are in the form: [id]*: url "optional title"
$text = preg_replace_callback('{
^[ ]{0,'.$less_than_tab.'}\*\[(.+?)\][ ]?: # abbr_id = $1
(.*) # text = $2 (no blank lines allowed)
}xm',
array($this, '_stripAbbreviations_callback'),
$text);
return $text;
}
protected function _stripAbbreviations_callback($matches) {
$abbr_word = $matches[1];
$abbr_desc = $matches[2];
if ($this->abbr_word_re)
$this->abbr_word_re .= '|';
$this->abbr_word_re .= preg_quote($abbr_word);
$this->abbr_desciptions[$abbr_word] = trim($abbr_desc);
return ''; # String that will replace the block
}
protected function doAbbreviations($text) {
#
# Find defined abbreviations in text and wrap them in <abbr> elements.
#
if ($this->abbr_word_re) {
// cannot use the /x modifier because abbr_word_re may
// contain significant spaces:
$text = preg_replace_callback('{'.
'(?<![\w\x1A])'.
'(?:'.$this->abbr_word_re.')'.
'(?![\w\x1A])'.
'}',
array($this, '_doAbbreviations_callback'), $text);
}
return $text;
}
protected function _doAbbreviations_callback($matches) {
$abbr = $matches[0];
if (isset($this->abbr_desciptions[$abbr])) {
$desc = $this->abbr_desciptions[$abbr];
if (empty($desc)) {
return $this->hashPart("<abbr>$abbr</abbr>");
} else {
$desc = $this->encodeAttribute($desc);
return $this->hashPart("<abbr title=\"$desc\">$abbr</abbr>");
}
} else {
return $matches[0];
}
}
}