/wp-content/plugins/jetpack/_inc/lib/markdown/gfm.php
PHP | 372 lines | 167 code | 46 blank | 159 comment | 10 complexity | 3874c7107983403578420b41324c956d MD5 | raw file
- <?php
- /**
- * GitHub-Flavoured Markdown. Inspired by Evan's plugin, but modified.
- *
- * @author Evan Solomon
- * @author Matt Wiebe <wiebe@automattic.com>
- * @link https://github.com/evansolomon/wp-github-flavored-markdown-comments
- *
- * Add a few extras from GitHub's Markdown implementation. Must be used in a WordPress environment.
- */
-
- class WPCom_GHF_Markdown_Parser extends MarkdownExtra_Parser {
-
- /**
- * Hooray somewhat arbitrary numbers that are fearful of 1.0.x.
- */
- const WPCOM_GHF_MARDOWN_VERSION = '0.9.0';
-
- /**
- * Use a [code] shortcode when encountering a fenced code block
- * @var boolean
- */
- public $use_code_shortcode = true;
-
- /**
- * Preserve shortcodes, untouched by Markdown.
- * This requires use within a WordPress installation.
- * @var boolean
- */
- public $preserve_shortcodes = true;
-
- /**
- * Preserve the legacy $latex your-latex-code-here$ style
- * LaTeX markup
- */
- public $preserve_latex = true;
-
- /**
- * Preserve single-line <code> blocks.
- * @var boolean
- */
- public $preserve_inline_code_blocks = true;
-
- /**
- * Strip paragraphs from the output. This is the right default for WordPress,
- * which generally wants to create its own paragraphs with `wpautop`
- * @var boolean
- */
- public $strip_paras = true;
-
- // Will run through sprintf - you can supply your own syntax if you want
- public $shortcode_start = '[code lang=%s]';
- public $shortcode_end = '[/code]';
-
- // Stores shortcodes we remove and then replace
- protected $preserve_text_hash = array();
-
- /**
- * Set environment defaults based on presence of key functions/classes.
- */
- public function __construct() {
- $this->use_code_shortcode = class_exists( 'SyntaxHighlighter' );
- $this->preserve_shortcodes = function_exists( 'get_shortcode_regex' );
- $this->preserve_latex = function_exists( 'latex_markup' );
- $this->strip_paras = function_exists( 'wpautop' );
-
- parent::MarkdownExtra_Parser();
- }
-
- /**
- * Overload to specify heading styles only if the hash has space(s) after it. This is actually in keeping with
- * the documentation and eases the semantic overload of the hash character.
- * #Will Not Produce a Heading 1
- * # This Will Produce a Heading 1
- *
- * @param string $text Markdown text
- * @return string HTML-transformed text
- */
- public function transform( $text ) {
- // Preserve anything inside a single-line <code> element
- if ( $this->preserve_inline_code_blocks ) {
- $text = $this->single_line_code_preserve( $text );
- }
- // Remove all shortcodes so their interiors are left intact
- if ( $this->preserve_shortcodes ) {
- $text = $this->shortcode_preserve( $text );
- }
- // Remove legacy LaTeX so it's left intact
- if ( $this->preserve_latex ) {
- $text = $this->latex_preserve( $text );
- }
-
- // escape line-beginning # chars that do not have a space after them.
- $text = preg_replace_callback( '|^#{1,6}( )?|um', array( $this, '_doEscapeForHashWithoutSpacing' ), $text );
-
- // run through core Markdown
- $text = parent::transform( $text );
-
- // Occasionally Markdown Extra chokes on a para structure, producing odd paragraphs.
- $text = str_replace( "<p><</p>\n\n<p>p>", '<p>', $text );
-
- // put start-of-line # chars back in place
- $text = $this->restore_leading_hash( $text );
-
- // Strip paras if set
- if ( $this->strip_paras ) {
- $text = $this->unp( $text );
- }
-
- // Restore preserved things like shortcodes/LaTeX
- $text = $this->do_restore( $text );
-
- return $text;
- }
-
- /**
- * Prevents blocks like <code>__this__</code> from turning into <code><strong>this</strong></code>
- * @param string $text Text that may need preserving
- * @return string Text that was preserved if needed
- */
- public function single_line_code_preserve( $text ) {
- return preg_replace_callback( '|<code\b[^>]*>(.*?)</code>|', array( $this, 'do_single_line_code_preserve' ), $text );
- }
-
- /**
- * Regex callback for inline code presevation
- * @param array $matches Regex matches
- * @return string Hashed content for later restoration
- */
- public function do_single_line_code_preserve( $matches ) {
- return '<code>' . $this->hash_block( $matches[1] ) . '</code>';
- }
-
- /**
- * Preserve code block contents by HTML encoding them. Useful before getting to KSES stripping.
- * @param string $text Markdown/HTML content
- * @return string Markdown/HTML content with escaped code blocks
- */
- public function codeblock_preserve( $text ) {
- return preg_replace_callback( "/^([`~]{3})([^`\n]+)?\n([^`~]+)(\\1)/m", array( $this, 'do_codeblock_preserve' ), $text );
- }
-
- /**
- * Regex callback for code block preservation.
- * @param array $matches Regex matches
- * @return string Codeblock with escaped interior
- */
- public function do_codeblock_preserve( $matches ) {
- $block = stripslashes( $matches[3] );
- $block = esc_html( $block );
- $open = $matches[1] . $matches[2] . "\n";
- return $open . $block . $matches[4];
- }
-
- /**
- * Restore previously preserved (i.e. escaped) code block contents.
- * @param string $text Markdown/HTML content with escaped code blocks
- * @return string Markdown/HTML content
- */
- public function codeblock_restore( $text ) {
- return preg_replace_callback( "/^([`~]{3})([^`\n]+)?\n([^`~]+)(\\1)/m", array( $this, 'do_codeblock_restore' ), $text );
- }
-
- /**
- * Regex callback for code block restoration (unescaping).
- * @param array $matches Regex matches
- * @return string Codeblock with unescaped interior
- */
- public function do_codeblock_restore( $matches ) {
- $block = html_entity_decode( $matches[3], ENT_QUOTES );
- $open = $matches[1] . $matches[2] . "\n";
- return $open . $block . $matches[4];
- }
-
- /**
- * Called to preserve legacy LaTeX like $latex some-latex-text $
- * @param string $text Text in which to preserve LaTeX
- * @return string Text with LaTeX replaced by a hash that will be restored later
- */
- protected function latex_preserve( $text ) {
- // regex from latex_remove()
- $regex = '%
- \$latex(?:=\s*|\s+)
- ((?:
- [^$]+ # Not a dollar
- |
- (?<=(?<!\\\\)\\\\)\$ # Dollar preceded by exactly one slash
- )+)
- (?<!\\\\)\$ # Dollar preceded by zero slashes
- %ix';
- $text = preg_replace_callback( $regex, array( $this, '_doRemoveText'), $text );
- return $text;
- }
-
- /**
- * Called to preserve WP shortcodes from being formatted by Markdown in any way.
- * @param string $text Text in which to preserve shortcodes
- * @return string Text with shortcodes replaced by a hash that will be restored later
- */
- protected function shortcode_preserve( $text ) {
- $text = preg_replace_callback( $this->get_shortcode_regex(), array( $this, '_doRemoveText' ), $text );
- return $text;
- }
-
- /**
- * Restores any text preserved by $this->hash_block()
- * @param string $text Text that may have hashed preservation placeholders
- * @return string Text with hashed preseravtion placeholders replaced by original text
- */
- protected function do_restore( $text ) {
- foreach( $this->preserve_text_hash as $hash => $value ) {
- $placeholder = $this->hash_maker( $hash );
- $text = str_replace( $placeholder, $value, $text );
- }
- // reset the hash
- $this->preserve_text_hash = array();
- return $text;
- }
-
- /**
- * Regex callback for text preservation
- * @param array $m Regex $matches array
- * @return string A placeholder that will later be replaced by the original text
- */
- protected function _doRemoveText( $m ) {
- return $this->hash_block( $m[0] );
- }
-
- /**
- * Call this to store a text block for later restoration.
- * @param string $text Text to preserve for later
- * @return string Placeholder that will be swapped out later for the original text
- */
- protected function hash_block( $text ) {
- $hash = md5( $text );
- $this->preserve_text_hash[ $hash ] = $text;
- $placeholder = $this->hash_maker( $hash );
- return $placeholder;
- }
-
- /**
- * Less glamorous than the Keymaker
- * @param string $hash An md5 hash
- * @return string A placeholder hash
- */
- protected function hash_maker( $hash ) {
- return 'MARKDOWN_HASH' . $hash . 'MARKDOWN_HASH';
- }
-
- /**
- * Remove bare <p> elements. <p>s with attributes will be preserved.
- * @param string $text HTML content
- * @return string <p>-less content
- */
- public function unp( $text ) {
- return preg_replace( "#<p>(.*?)</p>(\n|$)#ums", '$1$2', $text );
- }
-
- /**
- * A regex of all shortcodes currently registered by the current
- * WordPress installation
- * @uses get_shortcode_regex()
- * @return string A regex for grabbing shortcodes.
- */
- protected function get_shortcode_regex() {
- $pattern = get_shortcode_regex();
-
- // don't match markdown link anchors that could be mistaken for shortcodes.
- $pattern .= '(?!\()';
-
- return "/$pattern/s";
- }
-
- /**
- * Since we escape unspaced #Headings, put things back later.
- * @param string $text text with a leading escaped hash
- * @return string text with leading hashes unescaped
- */
- protected function restore_leading_hash( $text ) {
- return preg_replace( "/^(<p>)?(#|\\\\#)/um", "$1#", $text );
- }
-
- /**
- * Overload to support ```-fenced code blocks for pre-Markdown Extra 1.2.8
- * https://help.github.com/articles/github-flavored-markdown#fenced-code-blocks
- */
- public function doFencedCodeBlocks( $text ) {
- // If we're at least at 1.2.8, native fenced code blocks are in.
- // Below is just copied from it in case we somehow got loaded on
- // top of someone else's Markdown Extra
- if ( version_compare( MARKDOWNEXTRA_VERSION, '1.2.8', '>=' ) )
- return parent::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;
- }
-
- /**
- * Callback for pre-processing start of line hashes to slyly escape headings that don't
- * have a leading space
- * @param array $m preg_match matches
- * @return string possibly escaped start of line hash
- */
- public function _doEscapeForHashWithoutSpacing( $m ) {
- if ( ! isset( $m[1] ) )
- $m[0] = '\\' . $m[0];
- return $m[0];
- }
-
- /**
- * Overload to support Viper's [code] shortcode. Because awesome.
- */
- public function _doFencedCodeBlocks_callback( $matches ) {
- // in case we have some escaped leading hashes right at the start of the block
- $matches[4] = $this->restore_leading_hash( $matches[4] );
- // just MarkdownExtra_Parser if we're not going ultra-deluxe
- if ( ! $this->use_code_shortcode ) {
- return parent::_doFencedCodeBlocks_callback( $matches );
- }
-
- // default to a "text" class if one wasn't passed. Helps with encoding issues later.
- if ( empty( $matches[2] ) ) {
- $matches[2] = 'text';
- }
-
- $classname =& $matches[2];
- $codeblock = preg_replace_callback('/^\n+/', array( $this, '_doFencedCodeBlocks_newlines' ), $matches[4] );
-
- if ( $classname{0} == '.' )
- $classname = substr( $classname, 1 );
-
- $codeblock = esc_html( $codeblock );
- $codeblock = sprintf( $this->shortcode_start, $classname ) . "\n{$codeblock}" . $this->shortcode_end;
- return "\n\n" . $this->hashBlock( $codeblock ). "\n\n";
- }
-
- }