* @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 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::__construct(); } /** * 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 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 ); /** * Allow third-party plugins to define custom patterns that won't be processed by Markdown. * * @module markdown * * @since 3.9.2 * * @param array $custom_patterns Array of custom patterns to be ignored by Markdown. */ $custom_patterns = apply_filters( 'jetpack_markdown_preserve_pattern', array() ); if ( is_array( $custom_patterns ) && ! empty( $custom_patterns ) ) { foreach ( $custom_patterns as $pattern ) { $text = preg_replace_callback( $pattern, array( $this, '_doRemoveText'), $text ); } } // run through core Markdown $text = parent::transform( $text ); // Occasionally Markdown Extra chokes on a para structure, producing odd paragraphs. $text = str_replace( "

<

\n\n

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 __this__ from turning into this * @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( '|]*>(.*?)|', 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 '' . $this->hash_block( $matches[1] ) . ''; } /** * 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 ); $block = str_replace( '\\', '\\\\', $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 | (?<=(?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

elements.

s with attributes will be preserved. * @param string $text HTML content * @return string

-less content */ public function unp( $text ) { return preg_replace( "#

(.*?)

(\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( "/^(

)?(#|\\\\#)/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"; } }