references = []; * } * ``` */ trait LinkTrait { /** * @var array - A list of defined references in this document. */ protected $references = []; protected function parseLinkMarkers(): array { return array('['); } /** * Parses a link indicated by `[`. * * @marker [ */ protected function parseLink($markdown): array { if ( !in_array('parseLink', array_slice($this->context, 1)) && ($parts = $this->parseLinkOrImage($markdown)) !== false ) { list($text, $url, $title, $offset, $key) = $parts; return [ [ 'link', 'text' => $this->parseInline($text), 'url' => $url, 'title' => $title, 'refkey' => $key, 'orig' => substr($markdown, 0, $offset), ], $offset ]; } else { // Remove all starting [ markers to avoid next one being parsed as a link. $result = '['; $i = 1; while (isset($markdown[$i]) && $markdown[$i] === '[') { $result .= '['; $i++; } return [['text', $result], $i]; } } protected function parseImageMarkers(): array { return array('!['); } /** * Parses an image indicated by `![`. * * @marker ![ */ protected function parseImage($markdown): array { if ( ($parts = $this->parseLinkOrImage(substr($markdown, 1))) !== false ) { list($text, $url, $title, $offset, $key) = $parts; return [ [ 'image', 'text' => $text, 'url' => $url, 'title' => $title, 'refkey' => $key, 'orig' => substr($markdown, 0, $offset + 1), ], $offset + 1 ]; } else { // Remove all starting [ markers to avoid next one being parsed as a link. $result = '!'; $i = 1; while (isset($markdown[$i]) && $markdown[$i] === '[') { $result .= '['; $i++; } return [['text', $result], $i]; } } protected function parseLinkOrImage($markdown): array|false { if ( strpos($markdown, ']') !== false && preg_match( '/\[((?>(\\\\\[|\\\\\]|\\\\|[^\]\[\\\\])+|(?R))*)\]/', $markdown, $textMatches ) ) { $text = $textMatches[1]; $offset = strlen($textMatches[0]); $markdown = substr($markdown, $offset); $pattern = <<[^\s()]+)|(?R))*\) | # else match a link with title ^\(\s*(((?><[^<>\n]+>)|(?>[^\s()]+)|(?R))*)(\s+"(.*?)")?\s*\) )/xs REGEXP; if (preg_match($pattern, $markdown, $refMatches)) { // Inline link. $url = isset($refMatches[2]) ? $this->unEscapeBackslash($refMatches[2]) : ''; $lt = str_starts_with($url, '<'); $gt = str_ends_with($url, '>'); if (($lt && !$gt) || (!$lt && $gt)) { // Improperly matched brackets. return false; } if ($lt && $gt) { $url = str_replace(' ', '%20', substr($url, 1, -1)); } $title = empty($refMatches[5]) ? null : $this->unEscapeBackslash($refMatches[5]); $key = null; return [ $text, $url, $title, $offset + strlen($refMatches[0]), $key, ]; } elseif (preg_match('/^(\[(.*?)\])?/s', $markdown, $refMatches)) { // Reference style link. $key = empty($refMatches[2]) ? $text : $refMatches[2]; $key = function_exists("mb_convert_case") ? mb_convert_case($key, MB_CASE_FOLD, 'UTF-8') : strtolower($key); $url = null; $title = null; return [ $text, $url, $title, $offset + strlen($refMatches[0]), $key, ]; } } return false; } /** * Parses bracketed URL or email. * * @marker < */ protected function parseBracketedLink($text): array { if (strpos($text, '>') !== false) { if (!in_array('parseLink', $this->context)) { // Do not allow links within links. if ( preg_match( '/^<([a-z][a-z0-9\+\.\-]{1,31}:[^\s<>]*)>/i', $text, $matches ) ) { // URL. return [ [ 'url', $this->unEscapeBackslash($matches[1]) ], strlen($matches[0]) ]; } elseif ( preg_match('/^<([^\\\\\s>]*?@[^\s]*?\.\w+?)>/', $text, $matches ) ) { // Email address. return [ [ 'email', $this->unEscapeBackslash($matches[1]) ], strlen($matches[0]) ]; } } } return [['text', '<'], 1]; } protected function renderEmail($block): string { $email = $this->escapeHtmlEntities( $block[1], ENT_NOQUOTES | ENT_SUBSTITUTE ); return "$email"; } protected function renderUrl($block): string { $url = $this->escapeHtmlEntities($block[1], ENT_COMPAT); $decodedUrl = rawurldecode($block[1]); $secureUrlText = preg_match('//u', $decodedUrl) ? $decodedUrl : $block[1]; $text = $this->escapeHtmlEntities( $secureUrlText, ENT_NOQUOTES | ENT_SUBSTITUTE ); return "$text"; } protected function lookupReference($key): array|false { $normalizedKey = preg_replace('/\s+/', ' ', $key); if ( isset($this->references[$key]) || isset($this->references[$key = $normalizedKey]) ) { return $this->references[$key]; } return false; } protected function renderLink($block): string { if (isset($block['refkey'])) { if (($ref = $this->lookupReference($block['refkey'])) !== false) { $block = array_merge($block, $ref); } else { if (str_starts_with($block['orig'], '[')) { return '[' . $this->renderAbsy( $this->parseInline(substr($block['orig'], 1)) ); } return $block['orig']; } } return '' . $this->renderAbsy($block['text']) . ''; } protected function renderImage($block): string { if (isset($block['refkey'])) { if (($ref = $this->lookupReference($block['refkey'])) !== false) { $block = array_merge($block, $ref); } else { if (str_starts_with($block['orig'], '![')) { return '![' . $this->renderAbsy( $this->parseInline(substr($block['orig'], 2)) ); } return $block['orig']; } } return 'html5 ? '>' : ' />'); } #--------------------------------------------- # References #--------------------------------------------- protected function identifyReference($line): bool { return ( isset($line[0]) && ($line[0] === ' ' || $line[0] === '[') && preg_match( '/^ {0,3}\[(.+?)(?consumeParagraph($lines, $current); } $key = function_exists("mb_convert_case") ? mb_convert_case($matches[1], MB_CASE_FOLD, 'UTF-8') : strtolower($matches[1]) ; if (isset($matches[2])) { $url = $matches[2]; } else { // URL may be on the next line. if ( isset($lines[$current + 1]) && trim($lines[$current + 1]) !== '' ) { $url = trim($lines[$current + 1]); $current++; } else { // URL not found - consume lines as paragraph. return $this->consumeParagraph($lines, $current); } } if (str_starts_with($url, '<') && str_ends_with($url, '>')) { $url = str_replace(' ', '%20', substr($url, 1, -1)); } $ref = [ 'url' => $this->unEscapeBackslash($url), ]; if (isset($matches[3])) { $ref['title'] = $this->unEscapeBackslash($matches[3]); } else { // Title may be on the next line. if ( isset($lines[$current + 1]) && preg_match( '/^\s*[\(\'"](.+?)[\)\'"]\s*$/', $lines[$current + 1], $matches ) ) { $ref['title'] = $this->unEscapeBackslash($matches[1]); $current++; } } if (!isset($this->references[$key])) { $this->references[$key] = $ref; } $current++; } return [false, --$current]; } abstract protected function parseInline($text); abstract protected function renderAbsy($blocks); abstract protected function unEscapeBackslash($text); abstract protected function escapeHtmlEntities($text, $flags = 0); }