breaks_enabled = $breaks_enabled; return $this; } private $breaks_enabled = false; # # Synopsis # # Markdown is intended to be easy-to-read by humans - those of us who read # line by line, left to right, top to bottom. In order to take advantage of # this, Parsedown tries to read in a similar way. It breaks texts into # lines, it iterates through them and it looks at how they start and relate # to each other. # # Methods # function parse($text) { # standardize line breaks $text = str_replace("\r\n", "\n", $text); $text = str_replace("\r", "\n", $text); # replace tabs with spaces $text = str_replace("\t", ' ', $text); # remove surrounding line breaks $text = trim($text, "\n"); # split text into lines $lines = explode("\n", $text); # convert lines into html $text = $this->parse_block_elements($lines); # remove trailing line breaks $text = chop($text, "\n"); return $text; } # # Private private function parse_block_elements(array $lines, $context = '') { $blocks = array(); $block = array( 'type' => '', ); foreach ($lines as $line) { # context switch ($block['type']) { case 'fenced': if ( ! isset($block['closed'])) { if (preg_match('/^[ ]*'.$block['fence'][0].'{3,}[ ]*$/', $line)) { $block['closed'] = true; } else { if ($block['text'] !== '') { $block['text'] .= "\n"; } $block['text'] .= $line; } continue 2; } break; case 'markup': if ( ! isset($block['closed'])) { if (strpos($line, $block['start']) !== false) # opening tag { $block['depth']++; } if (strpos($line, $block['end']) !== false) # closing tag { if ($block['depth'] > 0) { $block['depth']--; } else { $block['closed'] = true; } } $block['text'] .= "\n".$line; continue 2; } break; } # ~ $indentation = 0; while(isset($line[$indentation]) and $line[$indentation] === ' ') { $indentation++; } $outdented_line = $indentation > 0 ? ltrim($line) : $line; # blank if ($outdented_line === '') { $block['interrupted'] = true; continue; } # context switch ($block['type']) { case 'quote': if ( ! isset($block['interrupted'])) { $line = preg_replace('/^[ ]*>[ ]?/', '', $line); $block['lines'] []= $line; continue 2; } break; case 'li': if ($block['indentation'] === $indentation and preg_match('/^'.$block['marker'].'[ ]+(.*)/', $outdented_line, $matches)) { unset($block['last']); $blocks []= $block; $block['last'] = true; $block['lines'] = array($matches[1]); unset($block['first']); unset($block['interrupted']); continue 2; } if ( ! isset($block['interrupted'])) { $line = preg_replace('/^[ ]{0,'.$block['baseline'].'}/', '', $line); $block['lines'] []= $line; continue 2; } elseif ($line[0] === ' ') { $block['lines'] []= ''; $line = preg_replace('/^[ ]{0,'.$block['baseline'].'}/', '', $line); $block['lines'] []= $line; unset($block['interrupted']); continue 2; } break; } # indentation sensitive types switch ($line[0]) { case ' ': # code if ($indentation >= 4) { $code_line = substr($line, 4); if ($block['type'] === 'code') { if (isset($block['interrupted'])) { $block['text'] .= "\n"; unset($block['interrupted']); } $block['text'] .= "\n".$code_line; } else { $blocks []= $block; $block = array( 'type' => 'code', 'text' => $code_line, ); } continue 2; } break; case '#': # atx heading (#) if (isset($line[1])) { $blocks []= $block; $level = 1; while (isset($line[$level]) and $line[$level] === '#') { $level++; } $block = array( 'type' => 'heading', 'text' => trim($line, '# '), 'level' => $level, ); continue 2; } break; case '-': case '=': # setext heading (===) if ($block['type'] === 'paragraph' and isset($block['interrupted']) === false) { $chopped_line = chop($line); $i = 1; while (isset($chopped_line[$i])) { if ($chopped_line[$i] !== $line[0]) { break 2; } $i++; } $block['type'] = 'heading'; $block['level'] = $line[0] === '-' ? 2 : 1; continue 2; } break; } # indentation insensitive types switch ($outdented_line[0]) { case '<': $position = strpos($outdented_line, '>'); if ($position > 1) { $substring = substr($outdented_line, 1, $position - 1); $substring = chop($substring); if (substr($substring, -1) === '/') { $is_self_closing = true; $substring = substr($substring, 0, -1); } $position = strpos($substring, ' '); if ($position) { $name = substr($substring, 0, $position); } else { $name = $substring; } if ( ! ctype_alpha($name)) { break; } if (in_array($name, self::$text_level_elements)) { break; } $blocks []= $block; if (isset($is_self_closing)) { $block = array( 'type' => 'self-closing tag', 'text' => $outdented_line, ); unset($is_self_closing); continue 2; } $block = array( 'type' => 'markup', 'text' => $outdented_line, 'start' => '<'.$name.'>', 'end' => '', 'depth' => 0, ); if (strpos($outdented_line, $block['end'])) { $block['closed'] = true; } continue 2; } break; case '>': # quote if (preg_match('/^>[ ]?(.*)/', $outdented_line, $matches)) { $blocks []= $block; $block = array( 'type' => 'quote', 'lines' => array( $matches[1], ), ); continue 2; } break; case '[': # reference $position = strpos($outdented_line, ']:'); if ($position) { $reference = array(); $label = substr($outdented_line, 1, $position - 1); $label = strtolower($label); $substring = substr($outdented_line, $position + 2); $substring = trim($substring); if ($substring === '') { break; } if ($substring[0] === '<') { $position = strpos($substring, '>'); if ($position === false) { break; } $reference['»'] = substr($substring, 1, $position - 1); $substring = substr($substring, $position + 1); } else { $position = strpos($substring, ' '); if ($position === false) { $reference['»'] = $substring; $substring = false; } else { $reference['»'] = substr($substring, 0, $position); $substring = substr($substring, $position + 1); } } if ($substring !== false) { if ($substring[0] !== '"' and $substring[0] !== "'" and $substring[0] !== '(') { break; } $last_char = substr($substring, -1); if ($last_char !== '"' and $last_char !== "'" and $last_char !== ')') { break; } $reference['#'] = substr($substring, 1, -1); } $this->reference_map[$label] = $reference; continue 2; } break; case '`': case '~': # fenced code block if (preg_match('/^([`]{3,}|[~]{3,})[ ]*(\S+)?[ ]*$/', $outdented_line, $matches)) { $blocks []= $block; $block = array( 'type' => 'fenced', 'text' => '', 'fence' => $matches[1], ); if (isset($matches[2])) { $block['language'] = $matches[2]; } continue 2; } break; case '*': case '+': case '-': case '_': # hr if (preg_match('/^([-*_])([ ]{0,2}\1){2,}[ ]*$/', $outdented_line)) { $blocks []= $block; $block = array( 'type' => 'rule', ); continue 2; } # li if (preg_match('/^([*+-][ ]+)(.*)/', $outdented_line, $matches)) { $blocks []= $block; $baseline = $indentation + strlen($matches[1]); $block = array( 'type' => 'li', 'indentation' => $indentation, 'baseline' => $baseline, 'marker' => '[*+-]', 'first' => true, 'last' => true, 'lines' => array(), ); $block['lines'] []= preg_replace('/^[ ]{0,4}/', '', $matches[2]); continue 2; } } # li if ($outdented_line[0] <= '9' and preg_match('/^(\d+[.][ ]+)(.*)/', $outdented_line, $matches)) { $blocks []= $block; $baseline = $indentation + strlen($matches[1]); $block = array( 'type' => 'li', 'indentation' => $indentation, 'baseline' => $baseline, 'marker' => '\d+[.]', 'first' => true, 'last' => true, 'ordered' => true, 'lines' => array(), ); $block['lines'] []= preg_replace('/^[ ]{0,4}/', '', $matches[2]); continue; } # paragraph if ($block['type'] === 'paragraph') { if (isset($block['interrupted'])) { $blocks []= $block; $block['text'] = $line; unset($block['interrupted']); } else { if ($this->breaks_enabled) { $block['text'] .= ' '; } $block['text'] .= "\n".$line; } } else { $blocks []= $block; $block = array( 'type' => 'paragraph', 'text' => $line, ); } } $blocks []= $block; unset($blocks[0]); # $blocks » HTML $markup = ''; foreach ($blocks as $block) { switch ($block['type']) { case 'paragraph': $text = $this->parse_span_elements($block['text']); if ($context === 'li' and $markup === '') { if (isset($block['interrupted'])) { $markup .= "\n".'

'.$text.'

'."\n"; } else { $markup .= $text; if (isset($blocks[2])) { $markup .= "\n"; } } } else { $markup .= '

'.$text.'

'."\n"; } break; case 'quote': $text = $this->parse_block_elements($block['lines']); $markup .= '
'."\n".$text.'
'."\n"; break; case 'code': $text = htmlspecialchars($block['text'], ENT_NOQUOTES, 'UTF-8'); $markup .= '
'.$text.'
'."\n"; break; case 'fenced': $text = htmlspecialchars($block['text'], ENT_NOQUOTES, 'UTF-8'); $markup .= '
'."\n"; break; case 'heading': $text = $this->parse_span_elements($block['text']); $markup .= ''.$text.''."\n"; break; case 'rule': $markup .= '
'."\n"; break; case 'li': if (isset($block['first'])) { $type = isset($block['ordered']) ? 'ol' : 'ul'; $markup .= '<'.$type.'>'."\n"; } if (isset($block['interrupted']) and ! isset($block['last'])) { $block['lines'] []= ''; } $text = $this->parse_block_elements($block['lines'], 'li'); $markup .= '
  • '.$text.'
  • '."\n"; if (isset($block['last'])) { $type = isset($block['ordered']) ? 'ol' : 'ul'; $markup .= ''."\n"; } break; case 'markup': $markup .= $block['text']."\n"; break; default: $markup .= $block['text']."\n"; } } return $markup; } private function parse_span_elements($text, $markers = array(" \n", '![', '&', '*', '<', '[', '\\', '_', '`', 'http', '~~')) { if (isset($text[1]) === false or $markers === array()) { return $text; } # ~ $markup = ''; while ($markers) { $closest_marker = null; $closest_marker_index = 0; $closest_marker_position = null; foreach ($markers as $index => $marker) { $marker_position = strpos($text, $marker); if ($marker_position === false) { unset($markers[$index]); continue; } if ($closest_marker === null or $marker_position < $closest_marker_position) { $closest_marker = $marker; $closest_marker_index = $index; $closest_marker_position = $marker_position; } } # ~ if ($closest_marker === null or isset($text[$closest_marker_position + 1]) === false) { $markup .= $text; break; } else { $markup .= substr($text, 0, $closest_marker_position); } $text = substr($text, $closest_marker_position); # ~ unset($markers[$closest_marker_index]); # ~ switch ($closest_marker) { case " \n": $markup .= '
    '."\n"; $offset = 3; break; case '![': case '[': if (strpos($text, ']') and preg_match('/\[((?:[^][]|(?R))*)\]/', $text, $matches)) { $element = array( '!' => $text[0] === '!', 'a' => $matches[1], ); $offset = strlen($matches[0]); if ($element['!']) { $offset++; } $remaining_text = substr($text, $offset); if ($remaining_text[0] === '(' and preg_match('/\([ ]*(.*?)(?:[ ]+[\'"](.+?)[\'"])?[ ]*\)/', $remaining_text, $matches)) { $element['»'] = $matches[1]; if (isset($matches[2])) { $element['#'] = $matches[2]; } $offset += strlen($matches[0]); } elseif ($this->reference_map) { $reference = $element['a']; if (preg_match('/^\s*\[(.*?)\]/', $remaining_text, $matches)) { $reference = $matches[1] ? $matches[1] : $element['a']; $offset += strlen($matches[0]); } $reference = strtolower($reference); if (isset($this->reference_map[$reference])) { $element['»'] = $this->reference_map[$reference]['»']; if (isset($this->reference_map[$reference]['#'])) { $element['#'] = $this->reference_map[$reference]['#']; } } else { unset($element); } } else { unset($element); } } if (isset($element)) { $element['»'] = str_replace('&', '&', $element['»']); $element['»'] = str_replace('<', '<', $element['»']); if ($element['!']) { $markup .= ''.$element['a'].'parse_span_elements($element['a'], $markers); $markup .= ''; } unset($element); } else { $markup .= $closest_marker; $offset = $closest_marker === '![' ? 2 : 1; } break; case '&': if (preg_match('/^&#?\w+;/', $text, $matches)) { $markup .= $matches[0]; $offset = strlen($matches[0]); } else { $markup .= '&'; $offset = 1; } break; case '*': case '_': if ($text[1] === $closest_marker and preg_match(self::$strong_regex[$closest_marker], $text, $matches)) { $markers[] = $closest_marker; $matches[1] = $this->parse_span_elements($matches[1], $markers); $markup .= ''.$matches[1].''; } elseif (preg_match(self::$em_regex[$closest_marker], $text, $matches)) { $markers[] = $closest_marker; $matches[1] = $this->parse_span_elements($matches[1], $markers); $markup .= ''.$matches[1].''; } if (isset($matches) and $matches) { $offset = strlen($matches[0]); } else { $markup .= $closest_marker; $offset = 1; } break; case '<': if (strpos($text, '>') !== false) { if ($text[1] === 'h' and preg_match('/^<(https?:[\/]{2}[^\s]+?)>/i', $text, $matches)) { $element_url = $matches[1]; $element_url = str_replace('&', '&', $element_url); $element_url = str_replace('<', '<', $element_url); $markup .= ''.$element_url.''; $offset = strlen($matches[0]); } elseif (strpos($text, '@') > 1 and preg_match('/<(\S+?@\S+?)>/', $text, $matches)) { $markup .= ''.$matches[1].''; $offset = strlen($matches[0]); } elseif (preg_match('/^<\/?\w.*?>/', $text, $matches)) { $markup .= $matches[0]; $offset = strlen($matches[0]); } else { $markup .= '<'; $offset = 1; } } else { $markup .= '<'; $offset = 1; } break; case '\\': if (in_array($text[1], self::$special_characters)) { $markup .= $text[1]; $offset = 2; } else { $markup .= '\\'; $offset = 1; } break; case '`': if (preg_match('/^(`+)[ ]*(.+?)[ ]*\1(?!`)/', $text, $matches)) { $element_text = $matches[2]; $element_text = htmlspecialchars($element_text, ENT_NOQUOTES, 'UTF-8'); $markup .= ''.$element_text.''; $offset = strlen($matches[0]); } else { $markup .= '`'; $offset = 1; } break; case 'http': if (preg_match('/^https?:[\/]{2}[^\s]+\b\/*/ui', $text, $matches)) { $element_url = $matches[0]; $element_url = str_replace('&', '&', $element_url); $element_url = str_replace('<', '<', $element_url); $markup .= ''.$element_url.''; $offset = strlen($matches[0]); } else { $markup .= 'http'; $offset = 4; } break; case '~~': if (preg_match('/^~~(?=\S)(.+?)(?<=\S)~~/', $text, $matches)) { $matches[1] = $this->parse_span_elements($matches[1], $markers); $markup .= ''.$matches[1].''; $offset = strlen($matches[0]); } else { $markup .= '~~'; $offset = 2; } break; } if (isset($offset)) { $text = substr($text, $offset); } $markers[$closest_marker_index] = $closest_marker; } return $markup; } # # Fields # private $reference_map = array(); # # Read-only private static $strong_regex = array( '*' => '/^[*]{2}((?:[^*]|[*][^*]*[*])+?)[*]{2}(?![*])/s', '_' => '/^__((?:[^_]|_[^_]*_)+?)__(?!_)/us', ); private static $em_regex = array( '*' => '/^[*]((?:[^*]|[*][*][^*]+?[*][*])+?)[*](?![*])/s', '_' => '/^_((?:[^_]|__[^_]*__)+?)_(?!_)\b/us', ); private static $special_characters = array( '\\', '`', '*', '_', '{', '}', '[', ']', '(', ')', '>', '#', '+', '-', '.', '!', ); private static $text_level_elements = array( 'a', 'br', 'bdo', 'abbr', 'blink', 'nextid', 'acronym', 'basefont', 'b', 'em', 'big', 'cite', 'small', 'spacer', 'listing', 'i', 'rp', 'sub', 'code', 'strike', 'marquee', 'q', 'rt', 'sup', 'font', 'strong', 's', 'tt', 'var', 'mark', 'u', 'xm', 'wbr', 'nobr', 'ruby', 'span', 'time', ); }