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| 1 | +<?php | |
| 2 | +/** | |
| 3 | + * GitHub-Flavoured Markdown. Inspired by Evan's plugin, but modified. | |
| 4 | + * | |
| 5 | + * @author Evan Solomon | |
| 6 | + * @author Matt Wiebe <[email protected]> | |
| 7 | + * @author Brandon Kraft <[email protected]> -- Strikedown support converted from GPL code at https://github.com/annaesvensson/yellow-markdown/blob/main/markdown.php | |
| 8 | + * @link https://github.com/evansolomon/wp-github-flavored-markdown-comments | |
| 9 | + * | |
| 10 | + * Add a few extras from GitHub's Markdown implementation. Must be used in a WordPress environment. | |
| 11 | + */ | |
| 12 | + | |
| 13 | +if ( ! defined( 'ABSPATH' ) ) { | |
| 14 | + exit( 0 ); | |
| 15 | +} | |
| 16 | + | |
| 17 | +class WPCom_GHF_Markdown_Parser extends MarkdownExtra_Parser { | |
| 18 | + | |
| 19 | + /** | |
| 20 | + * Hooray somewhat arbitrary numbers that are fearful of 1.0.x. | |
| 21 | + */ | |
| 22 | + const WPCOM_GHF_MARDOWN_VERSION = '0.9.1'; | |
| 23 | + | |
| 24 | + /** | |
| 25 | + * Use a [code] shortcode when encountering a fenced code block | |
| 26 | + * @var boolean | |
| 27 | + */ | |
| 28 | + public $use_code_shortcode = true; | |
| 29 | + | |
| 30 | + /** | |
| 31 | + * Preserve shortcodes, untouched by Markdown. | |
| 32 | + * This requires use within a WordPress installation. | |
| 33 | + * @var boolean | |
| 34 | + */ | |
| 35 | + public $preserve_shortcodes = true; | |
| 36 | + | |
| 37 | + /** | |
| 38 | + * Preserve the legacy $latex your-latex-code-here$ style | |
| 39 | + * LaTeX markup | |
| 40 | + */ | |
| 41 | + public $preserve_latex = true; | |
| 42 | + | |
| 43 | + /** | |
| 44 | + * Preserve single-line <code> blocks. | |
| 45 | + * @var boolean | |
| 46 | + */ | |
| 47 | + public $preserve_inline_code_blocks = true; | |
| 48 | + | |
| 49 | + /** | |
| 50 | + * Strip paragraphs from the output. This is the right default for WordPress, | |
| 51 | + * which generally wants to create its own paragraphs with `wpautop` | |
| 52 | + * @var boolean | |
| 53 | + */ | |
| 54 | + public $strip_paras = true; | |
| 55 | + | |
| 56 | + // Will run through sprintf - you can supply your own syntax if you want | |
| 57 | + public $shortcode_start = '[code lang=%s]'; | |
| 58 | + public $shortcode_end = '[/code]'; | |
| 59 | + | |
| 60 | + // Stores shortcodes we remove and then replace | |
| 61 | + protected $preserve_text_hash = array(); | |
| 62 | + | |
| 63 | + /** | |
| 64 | + * Set environment defaults based on presence of key functions/classes. | |
| 65 | + */ | |
| 66 | + public function __construct() { | |
| 67 | + $this->use_code_shortcode = class_exists( 'SyntaxHighlighter' ); | |
| 68 | + /** | |
| 69 | + * Allow processing shortcode contents. | |
| 70 | + * | |
| 71 | + * @module markdown | |
| 72 | + * | |
| 73 | + * @since 4.4.0 | |
| 74 | + * | |
| 75 | + * @param boolean $preserve_shortcodes Defaults to $this->preserve_shortcodes. | |
| 76 | + */ | |
| 77 | + $this->preserve_shortcodes = apply_filters( 'jetpack_markdown_preserve_shortcodes', $this->preserve_shortcodes ) && function_exists( 'get_shortcode_regex' ); | |
| 78 | + $this->preserve_latex = function_exists( 'latex_markup' ); | |
| 79 | + $this->strip_paras = function_exists( 'wpautop' ); | |
| 80 | + | |
| 81 | + $this->span_gamut['do_strikethrough'] = 55; | |
| 82 | + | |
| 83 | + parent::__construct(); | |
| 84 | + } | |
| 85 | + | |
| 86 | + /** | |
| 87 | + * Overload to specify heading styles only if the hash has space(s) after it. This is actually in keeping with | |
| 88 | + * the documentation and eases the semantic overload of the hash character. | |
| 89 | + * #Will Not Produce a Heading 1 | |
| 90 | + * # This Will Produce a Heading 1 | |
| 91 | + * | |
| 92 | + * @param string $text Markdown text | |
| 93 | + * @return string HTML-transformed text | |
| 94 | + */ | |
| 95 | + public function transform( $text ) { | |
| 96 | + // Preserve anything inside a single-line <code> element | |
| 97 | + if ( $this->preserve_inline_code_blocks ) { | |
| 98 | + $text = $this->single_line_code_preserve( $text ); | |
| 99 | + } | |
| 100 | + // Remove all shortcodes so their interiors are left intact | |
| 101 | + if ( $this->preserve_shortcodes ) { | |
| 102 | + $text = $this->shortcode_preserve( $text ); | |
| 103 | + } | |
| 104 | + // Remove legacy LaTeX so it's left intact | |
| 105 | + if ( $this->preserve_latex ) { | |
| 106 | + $text = $this->latex_preserve( $text ); | |
| 107 | + } | |
| 108 | + | |
| 109 | + // Do not process characters inside URLs. | |
| 110 | + $text = $this->urls_preserve( $text ); | |
| 111 | + | |
| 112 | + // escape line-beginning # chars that do not have a space after them. | |
| 113 | + $text = preg_replace_callback( '|^#{1,6}( )?|um', array( $this, '_doEscapeForHashWithoutSpacing' ), $text ); | |
| 114 | + | |
| 115 | + /** | |
| 116 | + * Allow third-party plugins to define custom patterns that won't be processed by Markdown. | |
| 117 | + * | |
| 118 | + * @module markdown | |
| 119 | + * | |
| 120 | + * @since 3.9.2 | |
| 121 | + * | |
| 122 | + * @param array $custom_patterns Array of custom patterns to be ignored by Markdown. | |
| 123 | + */ | |
| 124 | + $custom_patterns = apply_filters( 'jetpack_markdown_preserve_pattern', array() ); | |
| 125 | + if ( is_array( $custom_patterns ) && ! empty( $custom_patterns ) ) { | |
| 126 | + foreach ( $custom_patterns as $pattern ) { | |
| 127 | + $text = preg_replace_callback( $pattern, array( $this, '_doRemoveText'), $text ); | |
| 128 | + } | |
| 129 | + } | |
| 130 | + | |
| 131 | + // run through core Markdown | |
| 132 | + $text = parent::transform( $text ); | |
| 133 | + | |
| 134 | + // Occasionally Markdown Extra chokes on a para structure, producing odd paragraphs. | |
| 135 | + $text = str_replace( "<p><</p>\n\n<p>p>", '<p>', $text ); | |
| 136 | + | |
| 137 | + // put start-of-line # chars back in place | |
| 138 | + $text = $this->restore_leading_hash( $text ); | |
| 139 | + | |
| 140 | + // Strip paras if set | |
| 141 | + if ( $this->strip_paras ) { | |
| 142 | + $text = $this->unp( $text ); | |
| 143 | + } | |
| 144 | + | |
| 145 | + // Restore preserved things like shortcodes/LaTeX | |
| 146 | + $text = $this->do_restore( $text ); | |
| 147 | + | |
| 148 | + return $text; | |
| 149 | + } | |
| 150 | + | |
| 151 | + /** | |
| 152 | + * Prevents blocks like <code>__this__</code> from turning into <code><strong>this</strong></code> | |
| 153 | + * @param string $text Text that may need preserving | |
| 154 | + * @return string Text that was preserved if needed | |
| 155 | + */ | |
| 156 | + public function single_line_code_preserve( $text ) { | |
| 157 | + return preg_replace_callback( '|<code\b[^>]*>(.*?)</code>|', array( $this, 'do_single_line_code_preserve' ), $text ); | |
| 158 | + } | |
| 159 | + | |
| 160 | + /** | |
| 161 | + * Regex callback for inline code presevation | |
| 162 | + * @param array $matches Regex matches | |
| 163 | + * @return string Hashed content for later restoration | |
| 164 | + */ | |
| 165 | + public function do_single_line_code_preserve( $matches ) { | |
| 166 | + return '<code>' . $this->hash_block( $matches[1] ) . '</code>'; | |
| 167 | + } | |
| 168 | + | |
| 169 | + /** | |
| 170 | + * Preserve code block contents by HTML encoding them. Useful before getting to KSES stripping. | |
| 171 | + * @param string $text Markdown/HTML content | |
| 172 | + * @return string Markdown/HTML content with escaped code blocks | |
| 173 | + */ | |
| 174 | + public function codeblock_preserve( $text ) { | |
| 175 | + return preg_replace_callback( "/^([`~]{3})([^`\n]+)?\n([^`~]+)(\\1)/m", array( $this, 'do_codeblock_preserve' ), $text ); | |
| 176 | + } | |
| 177 | + | |
| 178 | + /** | |
| 179 | + * Regex callback for code block preservation. | |
| 180 | + * @param array $matches Regex matches | |
| 181 | + * @return string Codeblock with escaped interior | |
| 182 | + */ | |
| 183 | + public function do_codeblock_preserve( $matches ) { | |
| 184 | + $block = stripslashes( $matches[3] ); | |
| 185 | + $block = esc_html( $block ); | |
| 186 | + $block = str_replace( '\\', '\\\\', $block ); | |
| 187 | + $open = $matches[1] . $matches[2] . "\n"; | |
| 188 | + return $open . $block . $matches[4]; | |
| 189 | + } | |
| 190 | + | |
| 191 | + /** | |
| 192 | + * Restore previously preserved (i.e. escaped) code block contents. | |
| 193 | + * @param string $text Markdown/HTML content with escaped code blocks | |
| 194 | + * @return string Markdown/HTML content | |
| 195 | + */ | |
| 196 | + public function codeblock_restore( $text ) { | |
| 197 | + return preg_replace_callback( "/^([`~]{3})([^`\n]+)?\n([^`~]+)(\\1)/m", array( $this, 'do_codeblock_restore' ), $text ); | |
| 198 | + } | |
| 199 | + | |
| 200 | + /** | |
| 201 | + * Regex callback for code block restoration (unescaping). | |
| 202 | + * @param array $matches Regex matches | |
| 203 | + * @return string Codeblock with unescaped interior | |
| 204 | + */ | |
| 205 | + public function do_codeblock_restore( $matches ) { | |
| 206 | + $block = html_entity_decode( $matches[3], ENT_QUOTES ); | |
| 207 | + $open = $matches[1] . $matches[2] . "\n"; | |
| 208 | + return $open . $block . $matches[4]; | |
| 209 | + } | |
| 210 | + | |
| 211 | + /** | |
| 212 | + * Called to preserve legacy LaTeX like $latex some-latex-text $ | |
| 213 | + * @param string $text Text in which to preserve LaTeX | |
| 214 | + * @return string Text with LaTeX replaced by a hash that will be restored later | |
| 215 | + */ | |
| 216 | + protected function latex_preserve( $text ) { | |
| 217 | + // regex from latex_remove() | |
| 218 | + $regex = '% | |
| 219 | + \$latex(?:=\s*|\s+) | |
| 220 | + ((?: | |
| 221 | + [^$]+ # Not a dollar | |
| 222 | + | | |
| 223 | + (?<=(?<!\\\\)\\\\)\$ # Dollar preceded by exactly one slash | |
| 224 | + )+) | |
| 225 | + (?<!\\\\)\$ # Dollar preceded by zero slashes | |
| 226 | + %ix'; | |
| 227 | + $text = preg_replace_callback( $regex, array( $this, '_doRemoveText'), $text ); | |
| 228 | + return $text; | |
| 229 | + } | |
| 230 | + | |
| 231 | + /** | |
| 232 | + * Called to preserve WP shortcodes from being formatted by Markdown in any way. | |
| 233 | + * @param string $text Text in which to preserve shortcodes | |
| 234 | + * @return string Text with shortcodes replaced by a hash that will be restored later | |
| 235 | + */ | |
| 236 | + protected function shortcode_preserve( $text ) { | |
| 237 | + $text = preg_replace_callback( $this->get_shortcode_regex(), array( $this, '_doRemoveText' ), $text ); | |
| 238 | + return $text; | |
| 239 | + } | |
| 240 | + | |
| 241 | + /** | |
| 242 | + * Avoid characters inside URLs from being formatted by Markdown in any way. | |
| 243 | + * | |
| 244 | + * @param string $text Text in which to preserve URLs. | |
| 245 | + * | |
| 246 | + * @return string Text with URLs replaced by a hash that will be restored later. | |
| 247 | + */ | |
| 248 | + protected function urls_preserve( $text ) { | |
| 249 | + $text = preg_replace_callback( | |
| 250 | + '#(?<!<)(?:https?|ftp)://([^\s<>"\'\[\]()]+|\[(?1)*+\]|\((?1)*+\))+(?<![_*.?])#i', | |
| 251 | + array( $this, '_doRemoveText' ), | |
| 252 | + $text | |
| 253 | + ); | |
| 254 | + return $text; | |
| 255 | + } | |
| 256 | + | |
| 257 | + /** | |
| 258 | + * Restores any text preserved by $this->hash_block() | |
| 259 | + * @param string $text Text that may have hashed preservation placeholders | |
| 260 | + * @return string Text with hashed preseravtion placeholders replaced by original text | |
| 261 | + */ | |
| 262 | + protected function do_restore( $text ) { | |
| 263 | + // Reverse hashes to ensure nested blocks are restored. | |
| 264 | + $hashes = array_reverse( $this->preserve_text_hash, true ); | |
| 265 | + foreach( $hashes as $hash => $value ) { | |
| 266 | + $placeholder = $this->hash_maker( $hash ); | |
| 267 | + $text = str_replace( $placeholder, $value, $text ); | |
| 268 | + } | |
| 269 | + // reset the hash | |
| 270 | + $this->preserve_text_hash = array(); | |
| 271 | + return $text; | |
| 272 | + } | |
| 273 | + | |
| 274 | + /** | |
| 275 | + * Regex callback for text preservation | |
| 276 | + * @param array $m Regex $matches array | |
| 277 | + * @return string A placeholder that will later be replaced by the original text | |
| 278 | + */ | |
| 279 | + protected function _doRemoveText( $m ) { | |
| 280 | + return $this->hash_block( $m[0] ); | |
| 281 | + } | |
| 282 | + | |
| 283 | + /** | |
| 284 | + * Call this to store a text block for later restoration. | |
| 285 | + * @param string $text Text to preserve for later | |
| 286 | + * @return string Placeholder that will be swapped out later for the original text | |
| 287 | + */ | |
| 288 | + protected function hash_block( $text ) { | |
| 289 | + $hash = md5( $text ); | |
| 290 | + $this->preserve_text_hash[ $hash ] = $text; | |
| 291 | + $placeholder = $this->hash_maker( $hash ); | |
| 292 | + return $placeholder; | |
| 293 | + } | |
| 294 | + | |
| 295 | + /** | |
| 296 | + * Less glamorous than the Keymaker | |
| 297 | + * @param string $hash An md5 hash | |
| 298 | + * @return string A placeholder hash | |
| 299 | + */ | |
| 300 | + protected function hash_maker( $hash ) { | |
| 301 | + return 'MARKDOWN_HASH' . $hash . 'MARKDOWN_HASH'; | |
| 302 | + } | |
| 303 | + | |
| 304 | + /** | |
| 305 | + * Remove bare <p> elements. <p>s with attributes will be preserved. | |
| 306 | + * @param string $text HTML content | |
| 307 | + * @return string <p>-less content | |
| 308 | + */ | |
| 309 | + public function unp( $text ) { | |
| 310 | + return preg_replace( "#<p>(.*?)</p>(\n|$)#ums", '$1$2', $text ); | |
| 311 | + } | |
| 312 | + | |
| 313 | + /** | |
| 314 | + * A regex of all shortcodes currently registered by the current | |
| 315 | + * WordPress installation | |
| 316 | + * @uses get_shortcode_regex() | |
| 317 | + * @return string A regex for grabbing shortcodes. | |
| 318 | + */ | |
| 319 | + protected function get_shortcode_regex() { | |
| 320 | + $pattern = get_shortcode_regex(); | |
| 321 | + | |
| 322 | + // don't match markdown link anchors that could be mistaken for shortcodes. | |
| 323 | + $pattern .= '(?!\()'; | |
| 324 | + | |
| 325 | + return "/$pattern/s"; | |
| 326 | + } | |
| 327 | + | |
| 328 | + /** | |
| 329 | + * Since we escape unspaced #Headings, put things back later. | |
| 330 | + * @param string $text text with a leading escaped hash | |
| 331 | + * @return string text with leading hashes unescaped | |
| 332 | + */ | |
| 333 | + protected function restore_leading_hash( $text ) { | |
| 334 | + return preg_replace( "/^(<p>)?(#|\\\\#)/um", "$1#", $text ); | |
| 335 | + } | |
| 336 | + | |
| 337 | + /** | |
| 338 | + * Overload to support ```-fenced code blocks for pre-Markdown Extra 1.2.8 | |
| 339 | + * https://help.github.com/articles/github-flavored-markdown#fenced-code-blocks | |
| 340 | + */ | |
| 341 | + public function doFencedCodeBlocks( $text ) { | |
| 342 | + // If we're at least at 1.2.8, native fenced code blocks are in. | |
| 343 | + // Below is just copied from it in case we somehow got loaded on | |
| 344 | + // top of someone else's Markdown Extra | |
| 345 | + if ( version_compare( MARKDOWNEXTRA_VERSION, '1.2.8', '>=' ) ) | |
| 346 | + return parent::doFencedCodeBlocks( $text ); | |
| 347 | + | |
| 348 | + # | |
| 349 | + # Adding the fenced code block syntax to regular Markdown: | |
| 350 | + # | |
| 351 | + # ~~~ | |
| 352 | + # Code block | |
| 353 | + # ~~~ | |
| 354 | + # | |
| 355 | + $less_than_tab = $this->tab_width; | |
| 356 | + | |
| 357 | + $text = preg_replace_callback('{ | |
| 358 | + (?:\n|\A) | |
| 359 | + # 1: Opening marker | |
| 360 | + ( | |
| 361 | + (?:~{3,}|`{3,}) # 3 or more tildes/backticks. | |
| 362 | + ) | |
| 363 | + [ ]* | |
| 364 | + (?: | |
| 365 | + \.?([-_:a-zA-Z0-9]+) # 2: standalone class name | |
| 366 | + | | |
| 367 | + '.$this->id_class_attr_catch_re.' # 3: Extra attributes | |
| 368 | + )? | |
| 369 | + [ ]* \n # Whitespace and newline following marker. | |
| 370 | + | |
| 371 | + # 4: Content | |
| 372 | + ( | |
| 373 | + (?> | |
| 374 | + (?!\1 [ ]* \n) # Not a closing marker. | |
| 375 | + .*\n+ | |
| 376 | + )+ | |
| 377 | + ) | |
| 378 | + | |
| 379 | + # Closing marker. | |
| 380 | + \1 [ ]* (?= \n ) | |
| 381 | + }xm', | |
| 382 | + array($this, '_doFencedCodeBlocks_callback'), $text); | |
| 383 | + | |
| 384 | + return $text; | |
| 385 | + } | |
| 386 | + | |
| 387 | + /** | |
| 388 | + * Callback for pre-processing start of line hashes to slyly escape headings that don't | |
| 389 | + * have a leading space | |
| 390 | + * @param array $m preg_match matches | |
| 391 | + * @return string possibly escaped start of line hash | |
| 392 | + */ | |
| 393 | + public function _doEscapeForHashWithoutSpacing( $m ) { | |
| 394 | + if ( ! isset( $m[1] ) ) | |
| 395 | + $m[0] = '\\' . $m[0]; | |
| 396 | + return $m[0]; | |
| 397 | + } | |
| 398 | + | |
| 399 | + /** | |
| 400 | + * Overload to support Viper's [code] shortcode. Because awesome. | |
| 401 | + */ | |
| 402 | + public function _doFencedCodeBlocks_callback( $matches ) { | |
| 403 | + // in case we have some escaped leading hashes right at the start of the block | |
| 404 | + $matches[4] = $this->restore_leading_hash( $matches[4] ); | |
| 405 | + // just MarkdownExtra_Parser if we're not going ultra-deluxe | |
| 406 | + if ( ! $this->use_code_shortcode ) { | |
| 407 | + return parent::_doFencedCodeBlocks_callback( $matches ); | |
| 408 | + } | |
| 409 | + | |
| 410 | + // default to a "text" class if one wasn't passed. Helps with encoding issues later. | |
| 411 | + if ( empty( $matches[2] ) ) { | |
| 412 | + $matches[2] = 'text'; | |
| 413 | + } | |
| 414 | + | |
| 415 | + $classname =& $matches[2]; | |
| 416 | + $codeblock = preg_replace_callback('/^\n+/', array( $this, '_doFencedCodeBlocks_newlines' ), $matches[4] ); | |
| 417 | + | |
| 418 | + if ( $classname[0] == '.' ) | |
| 419 | + $classname = substr( $classname, 1 ); | |
| 420 | + | |
| 421 | + $codeblock = esc_html( $codeblock ); | |
| 422 | + $codeblock = sprintf( $this->shortcode_start, $classname ) . "\n{$codeblock}" . $this->shortcode_end; | |
| 423 | + return "\n\n" . $this->hashBlock( $codeblock ). "\n\n"; | |
| 424 | + } | |
| 425 | + | |
| 426 | + /** | |
| 427 | + * Add strikethrough support. | |
| 428 | + * | |
| 429 | + * GPL code modified from https://github.com/annaesvensson/yellow-markdown/blob/main/markdown.php | |
| 430 | + */ | |
| 431 | + public function do_strikethrough($text) { | |
| 432 | + $parts = preg_split("/(?<![~])(~~)(?![~])/", $text, -1, PREG_SPLIT_DELIM_CAPTURE); | |
| 433 | + if (count($parts)>3) { | |
| 434 | + $text = ""; | |
| 435 | + $open = false; | |
| 436 | + foreach ($parts as $part) { | |
| 437 | + if ($part=="~~") { | |
| 438 | + $text .= $open ? "</del>" : "<del>"; | |
| 439 | + $open = !$open; | |
| 440 | + } else { | |
| 441 | + $text .= $part; | |
| 442 | + } | |
| 443 | + } | |
| 444 | + if ($open) $text .= "</del>"; | |
| 445 | + } | |
| 446 | + return $text; | |
| 447 | + } | |
| 448 | + | |
| 449 | +} | |
