WordPress/wp-content/plugins/markdown.php
saxmatt 336bd345c4 Bump to Markdown 1.0
git-svn-id: http://svn.automattic.com/wordpress/trunk@1593 1a063a9b-81f0-0310-95a4-ce76da25c4cd
2004-09-04 20:48:57 +00:00

857 lines
21 KiB
PHP

<?php
#
# Markdown - A text-to-HTML conversion tool for web writers
#
# Copyright (c) 2004 John Gruber
# <http://daringfireball.net/projects/markdown/>
#
# Copyright (c) 2004 Michel Fortin - Translation to PHP
# <http://www.michelf.com/projects/php-markdown/>
#
# This version has been modified for inclusion in WordPress
# For the original please see Michel's site
global $MarkdownPHPVersion, $MarkdownSyntaxVersion,
$md_empty_element_suffix, $md_tab_width,
$md_nested_brackets_depth, $md_nested_brackets,
$md_escape_table, $md_backslash_escape_table;
$MarkdownPHPVersion = '1.0'; # Sat 21 Aug 2004
$MarkdownSyntaxVersion = '1.0'; # Fri 20 Aug 2004
#
# Global default settings:
#
$md_empty_element_suffix = " />"; # Change to ">" for HTML output
$md_tab_width = 4;
# -- WordPress Plugin Interface -----------------------------------------------
/*
Plugin Name: Markdown
Plugin URI: http://codex.wordpress.org/Plugin:Markdown
Description: <a href="http://daringfireball.net/projects/markdown/syntax">Markdown syntax</a> allows you to write using an easy-to-read, easy-to-write plain text format. Based on the original Perl version by <a href="http://daringfireball.net/">John Gruber</a>. <a href="http://www.michelf.com/projects/php-markdown/">More...</a>
Version: 1.0
Author: Michel Fortin
Author URI: http://www.michelf.com/
*/
if (isset($wp_version)) {
# Remove default WordPress auto-paragraph filter.
remove_filter('the_content', 'wpautop');
remove_filter('the_excerpt', 'wpautop');
remove_filter('comment_text', 'wpautop');
# Add Markdown filter with priority 6 (same as Textile).
add_filter('the_content', 'Markdown', 6);
add_filter('the_excerpt', 'Markdown', 6);
add_filter('comment_text', 'Markdown', 6);
}
function smarty_modifier_markdown($text) {
return Markdown($text);
}
$md_nested_brackets_depth = 6;
$md_nested_brackets =
str_repeat('(?>[^\[\]]+|\[', $md_nested_brackets_depth).
str_repeat('\])*', $md_nested_brackets_depth);
$md_escape_table = array(
"\\" => md5("\\"),
"`" => md5("`"),
"*" => md5("*"),
"_" => md5("_"),
"{" => md5("{"),
"}" => md5("}"),
"[" => md5("["),
"]" => md5("]"),
"(" => md5("("),
")" => md5(")"),
"#" => md5("#"),
"." => md5("."),
"!" => md5("!")
);
# Create an identical table but for escaped characters.
$md_backslash_escape_table;
foreach ($md_escape_table as $key => $char)
$md_backslash_escape_table["\\$key"] = $char;
function Markdown($text) {
global $md_urls, $md_titles, $md_html_blocks;
$md_urls = array();
$md_titles = array();
$md_html_blocks = array();
$text = str_replace(array("\r\n", "\r"), "\n", $text);
$text .= "\n\n";
$text = _Detab($text);
$text = preg_replace('/^[ \t]+$/m', '', $text);
$text = _HashHTMLBlocks($text);
$text = _StripLinkDefinitions($text);
$text = _EscapeSpecialChars($text);
$text = _RunBlockGamut($text);
$text = _UnescapeSpecialChars($text);
return $text . "\n";
}
function _StripLinkDefinitions($text) {
$text = preg_replace_callback('{
^[ \t]*\[(.+)\]: # id = $1
[ \t]*
\n? # maybe *one* newline
[ \t]*
<?(\S+?)>? # url = $2
[ \t]*
\n? # maybe one newline
[ \t]*
(?:
# Todo: Titles are delimited by "quotes" or (parens).
["(]
(.+?) # title = $3
[")]
[ \t]*
)? # title is optional
(?:\n+|\Z)
}xm',
'_StripLinkDefinitions_callback',
$text);
return $text;
}
function _StripLinkDefinitions_callback($matches) {
global $md_urls, $md_titles;
$link_id = strtolower($matches[1]);
$md_urls[$link_id] = _EncodeAmpsAndAngles($matches[2]);
if (isset($matches[3]))
$md_titles[$link_id] = htmlentities($matches[3]);
return ''; # String that will replace the block
}
function _HashHTMLBlocks($text) {
$block_tags_a = 'p|div|h[1-6]|blockquote|pre|table|dl|ol|ul|'.
'script|noscript|form|fieldset|iframe|math|ins|del';
$block_tags_b = 'p|div|h[1-6]|blockquote|pre|table|dl|ol|ul|'.
'script|noscript|form|fieldset|iframe|math';
$text = preg_replace_callback("{
( # save in $1
^ # start of line (with /m)
<($block_tags_a) # start tag = $2
\\b # word break
(.*\\n)*? # any number of lines, minimally matching
</\\2> # the matching end tag
[ \\t]* # trailing spaces/tabs
(?=\\n+|\\Z) # followed by a newline or end of document
)
}xm",
'_HashHTMLBlocks_callback',
$text);
$text = preg_replace_callback("{
( # save in $1
^ # start of line (with /m)
<($block_tags_b) # start tag = $2
\\b # word break
(.*\\n)*? # any number of lines, minimally matching
.*</\\2> # the matching end tag
[ \\t]* # trailing spaces/tabs
(?=\\n+|\\Z) # followed by a newline or end of document
)
}xm",
'_HashHTMLBlocks_callback',
$text);
$text = preg_replace_callback('{
(?:
(?<=\n\n) # Starting after a blank line
| # or
\A\n? # the beginning of the doc
)
( # save in $1
[ \t]*
<(hr) # start tag = $2
\b # word break
([^<>])*? #
/?> # the matching end tag
(?=\n{2,}|\Z) # followed by a blank line or end of document
)
}x',
'_HashHTMLBlocks_callback',
$text);
return $text;
}
function _HashHTMLBlocks_callback($matches) {
global $md_html_blocks;
$text = $matches[1];
$key = md5($text);
$md_html_blocks[$key] = $text;
return "\n\n$key\n\n"; # String that will replace the block
}
function _RunBlockGamut($text) {
global $md_empty_element_suffix;
$text = _DoHeaders($text);
# Do Horizontal Rules:
$text = preg_replace(
array('/^( ?\* ?){3,}$/m',
'/^( ?- ?){3,}$/m',
'/^( ?_ ?){3,}$/m'),
"\n<hr$md_empty_element_suffix\n",
$text);
$text = _DoLists($text);
$text = _DoCodeBlocks($text);
$text = _DoBlockQuotes($text);
# Make links out of things like `<http://example.com/>`
$text = _DoAutoLinks($text);
$text = _HashHTMLBlocks($text);
$text = _FormParagraphs($text);
return $text;
}
function _RunSpanGamut($text) {
global $md_empty_element_suffix;
$text = _DoCodeSpans($text);
# Fix unencoded ampersands and <'s:
$text = _EncodeAmpsAndAngles($text);
# Process anchor and image tags. Images must come first,
# because ![foo][f] looks like an anchor.
$text = _DoImages($text);
$text = _DoAnchors($text);
$text = _DoItalicsAndBold($text);
$text = preg_replace('/ {2,}\n/', "<br$md_empty_element_suffix\n", $text);
return $text;
}
function _EscapeSpecialChars($text) {
global $md_escape_table;
$tokens = _TokenizeHTML($text);
$text = ''; # rebuild $text from the tokens
foreach ($tokens as $cur_token) {
if ($cur_token[0] == 'tag') {
$cur_token[1] = str_replace(array('*', '_'),
array($md_escape_table['*'], $md_escape_table['_']),
$cur_token[1]);
$text .= $cur_token[1];
} else {
$t = $cur_token[1];
$t = _EncodeBackslashEscapes($t);
$text .= $t;
}
}
return $text;
}
function _DoAnchors($text) {
global $md_nested_brackets;
#
# First, handle reference-style links: [link text] [id]
#
$text = preg_replace_callback("{
( # wrap whole match in $1
\\[
($md_nested_brackets) # link text = $2
\\]
[ ]? # one optional space
(?:\\n[ ]*)? # one optional newline followed by spaces
\\[
(.*?) # id = $3
\\]
)
}xs",
'_DoAnchors_reference_callback', $text);
$text = preg_replace_callback("{
( # wrap whole match in $1
\\[
($md_nested_brackets) # link text = $2
\\]
\\( # literal paren
[ \\t]*
<?(.+?)>? # href = $3
[ \\t]*
( # $4
(['\"]) # quote char = $5
(.*?) # Title = $6
\\5 # matching quote
)? # title is optional
\\)
)
}xs",
'_DoAnchors_inline_callback', $text);
return $text;
}
function _DoAnchors_reference_callback($matches) {
global $md_urls, $md_titles, $md_escape_table;
$whole_match = $matches[1];
$link_text = $matches[2];
$link_id = strtolower($matches[3]);
if ($link_id == "") {
$link_id = strtolower($link_text); # for shortcut links like [this][].
}
if (isset($md_urls[$link_id])) {
$url = $md_urls[$link_id];
# We've got to encode these to avoid conflicting with italics/bold.
$url = str_replace(array('*', '_'),
array($md_escape_table['*'], $md_escape_table['_']),
$url);
$result = "<a href=\"$url\"";
if ( isset( $md_titles[$link_id] ) ) {
$title = $md_titles[$link_id];
$title = str_replace(array('*', '_'),
array($md_escape_table['*'],
$md_escape_table['_']), $title);
$result .= " title=\"$title\"";
}
$result .= ">$link_text</a>";
}
else {
$result = $whole_match;
}
return $result;
}
function _DoAnchors_inline_callback($matches) {
global $md_escape_table;
$whole_match = $matches[1];
$link_text = $matches[2];
$url = $matches[3];
$title = $matches[6];
# We've got to encode these to avoid conflicting with italics/bold.
$url = str_replace(array('*', '_'),
array($md_escape_table['*'], $md_escape_table['_']),
$url);
$result = "<a href=\"$url\"";
if (isset($title)) {
$title = str_replace('"', '&quot', $title);
$title = str_replace(array('*', '_'),
array($md_escape_table['*'], $md_escape_table['_']),
$title);
$result .= " title=\"$title\"";
}
$result .= ">$link_text</a>";
return $result;
}
function _DoImages($text) {
$text = preg_replace_callback('{
( # wrap whole match in $1
!\[
(.*?) # alt text = $2
\]
[ ]? # one optional space
(?:\n[ ]*)? # one optional newline followed by spaces
\[
(.*?) # id = $3
\]
)
}xs',
'_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
!\\[
(.*?) # alt text = $2
\\]
\\( # literal paren
[ \\t]*
<?(\S+?)>? # src url = $3
[ \\t]*
( # $4
(['\"]) # quote char = $5
(.*?) # title = $6
\\5 # matching quote
[ \\t]*
)? # title is optional
\\)
)
}xs",
'_DoImages_inline_callback', $text);
return $text;
}
function _DoImages_reference_callback($matches) {
global $md_urls, $md_titles, $md_empty_element_suffix, $md_escape_table;
$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 = str_replace('"', '&quot;', $alt_text);
if (isset($md_urls[$link_id])) {
$url = $md_urls[$link_id];
# We've got to encode these to avoid conflicting with italics/bold.
$url = str_replace(array('*', '_'),
array($md_escape_table['*'], $md_escape_table['_']),
$url);
$result = "<img src=\"$url\" alt=\"$alt_text\"";
if (isset($md_titles[$link_id])) {
$title = $md_titles[$link_id];
$title = str_replace(array('*', '_'),
array($md_escape_table['*'],
$md_escape_table['_']), $title);
$result .= " title=\"$title\"";
}
$result .= $md_empty_element_suffix;
}
else {
# If there's no such link ID, leave intact:
$result = $whole_match;
}
return $result;
}
function _DoImages_inline_callback($matches) {
global $md_empty_element_suffix, $md_escape_table;
$whole_match = $matches[1];
$alt_text = $matches[2];
$url = $matches[3];
$title = '';
if (isset($matches[6])) {
$title = $matches[6];
}
$alt_text = str_replace('"', '&quot;', $alt_text);
$title = str_replace('"', '&quot;', $title);
# We've got to encode these to avoid conflicting with italics/bold.
$url = str_replace(array('*', '_'),
array($md_escape_table['*'], $md_escape_table['_']),
$url);
$result = "<img src=\"$url\" alt=\"$alt_text\"";
if (isset($title)) {
$title = str_replace(array('*', '_'),
array($md_escape_table['*'], $md_escape_table['_']),
$title);
$result .= " title=\"$title\""; # $title already quoted
}
$result .= $md_empty_element_suffix;
return $result;
}
function _DoHeaders($text) {
$text = preg_replace(
array("/(.+)[ \t]*\n=+[ \t]*\n+/e",
"/(.+)[ \t]*\n-+[ \t]*\n+/e"),
array("'<h1>'._RunSpanGamut(_UnslashQuotes('\\1')).'</h1>\n\n'",
"'<h2>'._RunSpanGamut(_UnslashQuotes('\\1')).'</h2>\n\n'"),
$text);
$text = preg_replace("{
^(\\#{1,6}) # $1 = string of #'s
[ \\t]*
(.+?) # $2 = Header text
[ \\t]*
\\#* # optional closing #'s (not counted)
\\n+
}xme",
"'<h'.strlen('\\1').'>'._RunSpanGamut(_UnslashQuotes('\\2')).'</h'.strlen('\\1').'>\n\n'",
$text);
return $text;
}
function _DoLists($text) {
#
# Form HTML ordered (numbered) and unordered (bulleted) lists.
#
global $md_tab_width;
$less_than_tab = $md_tab_width - 1;
# Re-usable patterns to match list item bullets and number markers:
$marker_ul = '[*+-]';
$marker_ol = '\d+[.]';
$marker_any = "(?:$marker_ul|$marker_ol)";
$text = preg_replace_callback("{
( # $1
( # $2
^[ ]{0,$less_than_tab}
($marker_any) # $3 - first list item marker
[ \\t]+
)
(?s:.+?)
( # $4
\\z
|
\\n{2,}
(?=\\S)
(?! # Negative lookahead for another list item marker
[ \\t]*
{$marker_any}[ \\t]+
)
)
)
}xm",
'_DoLists_callback', $text);
return $text;
}
function _DoLists_callback($matches) {
# Re-usable patterns to match list item bullets and number markers:
$marker_ul = '[*+-]';
$marker_ol = '\d+[.]';
$marker_any = "(?:$marker_ul|$marker_ol)";
$list = $matches[1];
$list_type = preg_match('/[*+-]/', $matches[3]) ? "ul" : "ol";
# Turn double returns into triple returns, so that we can make a
# paragraph for the last item in a list, if necessary:
$list = preg_replace("/\n{2,}/", "\n\n\n", $list);
$result = _ProcessListItems($list, $marker_any);
$result = "<$list_type>\n" . $result . "</$list_type>\n\n";
return $result;
}
function _ProcessListItems($list_str, $marker_any) {
# trim trailing blank lines:
$list_str = preg_replace("/\n{2,}\\z/", "\n", $list_str);
$list_str = preg_replace_callback('{
(\n)? # leading line = $1
(^[ \t]*) # leading whitespace = $2
('.$marker_any.') [ \t]+ # list marker = $3
((?s:.+?) # list item text = $4
(\n{1,2}))
(?= \n* (\z | \2 ('.$marker_any.') [ \t]+))
}xm',
'_ProcessListItems_callback', $list_str);
return $list_str;
}
function _ProcessListItems_callback($matches) {
$item = $matches[4];
$leading_line = $matches[1];
$leading_space = $matches[2];
if ($leading_line || preg_match('/\n{2,}/', $item)) {
$item = _RunBlockGamut(_Outdent($item));
#$item =~ s/\n+/\n/g;
}
else {
# Recursion for sub-lists:
$item = _DoLists(_Outdent($item));
$item = rtrim($item, "\n");
$item = _RunSpanGamut($item);
}
return "<li>" . $item . "</li>\n";
}
function _DoCodeBlocks($text) {
global $md_tab_width;
$text = preg_replace_callback("{
(?:\\n\\n|\\A)
( # $1 = the code block -- one or more lines, starting with a space/tab
(?:
(?:[ ]\{$md_tab_width} | \\t) # Lines must start with a tab or a tab-width of spaces
.*\\n+
)+
)
((?=^[ ]{0,$md_tab_width}\\S)|\\Z) # Lookahead for non-space at line-start, or end of doc
}xm",
'_DoCodeBlocks_callback', $text);
return $text;
}
function _DoCodeBlocks_callback($matches) {
$codeblock = $matches[1];
$codeblock = _EncodeCode(_Outdent($codeblock));
$codeblock = _Detab($codeblock);
# trim leading newlines and trailing whitespace
$codeblock = preg_replace(array('/\A\n+/', '/\s+\z/'), '', $codeblock);
$result = "\n\n<pre><code>" . $codeblock . "\n</code></pre>\n\n";
return $result;
}
function _DoCodeSpans($text) {
$text = preg_replace_callback("@
(`+) # $1 = Opening run of `
(.+?) # $2 = The code block
(?<!`)
\\1
(?!`)
@xs",
'_DoCodeSpans_callback', $text);
return $text;
}
function _DoCodeSpans_callback($matches) {
$c = $matches[2];
$c = preg_replace('/^[ \t]*/', '', $c); # leading whitespace
$c = preg_replace('/[ \t]*$/', '', $c); # trailing whitespace
$c = _EncodeCode($c);
return "<code>$c</code>";
}
function _EncodeCode($_) {
global $md_escape_table;
$_ = str_replace('&', '&amp;', $_);
$_ = str_replace(array('<', '>'),
array('&lt;', '&gt;'), $_);
$_ = str_replace(array_keys($md_escape_table),
array_values($md_escape_table), $_);
return $_;
}
function _DoItalicsAndBold($text) {
# <strong> must go first:
$text = preg_replace('{ (\*\*|__) (?=\S) (.+?) (?<=\S) \1 }sx',
'<strong>\2</strong>', $text);
# Then <em>:
$text = preg_replace('{ (\*|_) (?=\S) (.+?) (?<=\S) \1 }sx',
'<em>\2</em>', $text);
return $text;
}
function _DoBlockQuotes($text) {
$text = preg_replace_callback('/
( # Wrap whole match in $1
(
^[ \t]*>[ \t]? # ">" at the start of a line
.+\n # rest of the first line
(.+\n)* # subsequent consecutive lines
\n* # blanks
)+
)
/xm',
'_DoBlockQuotes_callback', $text);
return $text;
}
function _DoBlockQuotes_callback($matches) {
$bq = $matches[1];
# trim one level of quoting - trim whitespace-only lines
$bq = preg_replace(array('/^[ \t]*>[ \t]?/m', '/^[ \t]+$/m'), '', $bq);
$bq = _RunBlockGamut($bq); # recurse
$bq = preg_replace('/^/m', " ", $bq);
# These leading spaces screw with <pre> content, so we need to fix that:
$bq = preg_replace_callback('{(\s*<pre>.+?</pre>)}sx',
'_DoBlockQuotes_callback2', $bq);
return "<blockquote>\n$bq\n</blockquote>\n\n";
}
function _DoBlockQuotes_callback2($matches) {
$pre = $matches[1];
$pre = preg_replace('/^ /m', '', $pre);
return $pre;
}
function _FormParagraphs($text) {
global $md_html_blocks;
# Strip leading and trailing lines:
$text = preg_replace(array('/\A\n+/', '/\n+\z/'), '', $text);
$grafs = preg_split('/\n{2,}/', $text, -1, PREG_SPLIT_NO_EMPTY);
$count = count($grafs);
foreach ($grafs as $key => $value) {
if (!isset( $md_html_blocks[$value] )) {
$value = _RunSpanGamut($value);
$value = preg_replace('/^([ \t]*)/', '<p>', $value);
$value .= "</p>";
$grafs[$key] = $value;
}
}
foreach ($grafs as $key => $value) {
if (isset( $md_html_blocks[$value] )) {
$grafs[$key] = $md_html_blocks[$value];
}
}
return implode("\n\n", $grafs);
}
function _EncodeAmpsAndAngles($text) {
$text = preg_replace('/&(?!#?[xX]?(?:[0-9a-fA-F]+|\w+);)/',
'&amp;', $text);;
# Encode naked <'s
$text = preg_replace('{<(?![a-z/?\$!])}i', '&lt;', $text);
return $text;
}
function _EncodeBackslashEscapes($text) {
global $md_escape_table, $md_backslash_escape_table;
# Must process escaped backslashes first.
return str_replace(array_keys($md_backslash_escape_table),
array_values($md_backslash_escape_table), $text);
}
function _DoAutoLinks($text) {
$text = preg_replace("!<((https?|ftp):[^'\">\\s]+)>!",
'<a href="\1">\1</a>', $text);
# Email addresses: <address@domain.foo>
$text = preg_replace('{
<
(
[-.\w]+
\@
[-a-z0-9]+(\.[-a-z0-9]+)*\.[a-z]+
)
>
}exi',
"_EncodeEmailAddress(_UnescapeSpecialChars(_UnslashQuotes('\\1')))",
$text);
return $text;
}
function _EncodeEmailAddress($addr) {
$addr = "mailto:" . $addr;
$length = strlen($addr);
# leave ':' alone (to spot mailto: later)
$addr = preg_replace_callback('/([^\:])/',
'_EncodeEmailAddress_callback', $addr);
$addr = "<a href=\"$addr\">$addr</a>";
# strip the mailto: from the visible part
$addr = preg_replace('/">.+?:/', '">', $addr);
return $addr;
}
function _EncodeEmailAddress_callback($matches) {
$char = $matches[1];
$r = rand(0, 100);
# roughly 10% raw, 45% hex, 45% dec
# '@' *must* be encoded. I insist.
if ($r > 90 && $char != '@') return $char;
if ($r < 45) return '&#x'.dechex(ord($char)).';';
return '&#'.ord($char).';';
}
function _UnescapeSpecialChars($text) {
global $md_escape_table;
return str_replace(array_values($md_escape_table),
array_keys($md_escape_table), $text);
}
if (!function_exists('_TokenizeHTML')) {
function _TokenizeHTML($str) {
$index = 0;
$tokens = array();
$depth = 6;
$nested_tags = str_repeat('(?:<[a-z\/!$](?:[^<>]|',$depth)
.str_repeat(')*>)', $depth);
$match = "(?s:<!(?:--.*?--\s*)+>)|". # comment
"(?s:<\?.*?\?>)|". # processing instruction
"$nested_tags"; # nested tags
$parts = preg_split("/($match)/", $str, -1, PREG_SPLIT_DELIM_CAPTURE);
foreach ($parts as $part) {
if (++$index % 2 && $part != '')
array_push($tokens, array('text', $part));
else
array_push($tokens, array('tag', $part));
}
return $tokens;
}
}
function _Outdent($text) {
global $md_tab_width;
return preg_replace("/^(\\t|[ ]{1,$md_tab_width})/m", "", $text);
}
function _Detab($text) {
global $md_tab_width;
$text = preg_replace(
"/(.*?)\t/e",
"'\\1'.str_repeat(' ', $md_tab_width - strlen('\\1') % $md_tab_width)",
$text);
return $text;
}
function _UnslashQuotes($text) {
return str_replace('\"', '"', $text);
}
?>