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<?php
#
#
# Parsedown
# http://parsedown.org
#
# (c) Emanuil Rusev
# http://erusev.com
#
# For the full license information, view the LICENSE file that was distributed
# with this source code.
#
#
class Parsedown {
# Multiton
static function instance( $name = 'default' ) {
if ( isset( self::$instances[ $name ] ) ) {
return self::$instances[ $name ];
}
$instance = new Parsedown();
self::$instances[ $name ] = $instance;
return $instance;
}
private static $instances = array();
#
# Setters
#
# Enables GFM line breaks.
function set_breaks_enabled( $breaks_enabled ) {
$this->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' => '</' . $name . '>',
'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" . '<p>' . $text . '</p>' . "\n";
} else {
$markup .= $text;
if ( isset( $blocks[2] ) ) {
$markup .= "\n";
}
}
} else {
$markup .= '<p>' . $text . '</p>' . "\n";
}
break;
case 'quote':
$text = $this->parse_block_elements( $block['lines'] );
$markup .= '<blockquote>' . "\n" . $text . '</blockquote>' . "\n";
break;
case 'code':
$text = htmlspecialchars( $block['text'], ENT_NOQUOTES, 'UTF-8' );
$markup .= '<pre><code>' . $text . '</code></pre>' . "\n";
break;
case 'fenced':
$text = htmlspecialchars( $block['text'], ENT_NOQUOTES, 'UTF-8' );
$markup .= '<pre><code';
if ( isset( $block['language'] ) ) {
$markup .= ' class="language-' . $block['language'] . '"';
}
$markup .= '>' . $text . '</code></pre>' . "\n";
break;
case 'heading':
$text = $this->parse_span_elements( $block['text'] );
$markup .= '<h' . $block['level'] . '>' . $text . '</h' . $block['level'] . '>' . "\n";
break;
case 'rule':
$markup .= '<hr />' . "\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 .= '<li>' . $text . '</li>' . "\n";
if ( isset( $block['last'] ) ) {
$type = isset( $block['ordered'] ) ? 'ol' : 'ul';
$markup .= '</' . $type . '>' . "\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 .= '<br />' . "\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 .= '<img alt="' . $element['a'] . '" src="' . $element['»'] . '"';
if ( isset( $element['#'] ) ) {
$markup .= ' title="' . $element['#'] . '"';
}
$markup .= ' />';
} else {
$element['a'] = $this->parse_span_elements( $element['a'], $markers );
$markup .= '<a href="' . $element['»'] . '"';
if ( isset( $element['#'] ) ) {
$markup .= ' title="' . $element['#'] . '"';
}
$markup .= '>' . $element['a'] . '</a>';
}
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 .= '<strong>' . $matches[1] . '</strong>';
} elseif ( preg_match( self::$em_regex[ $closest_marker ], $text, $matches ) ) {
$markers[] = $closest_marker;
$matches[1] = $this->parse_span_elements( $matches[1], $markers );
$markup .= '<em>' . $matches[1] . '</em>';
}
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 .= '<a href="' . $element_url . '">' . $element_url . '</a>';
$offset = strlen( $matches[0] );
} elseif ( strpos( $text, '@' ) > 1 and preg_match( '/<(\S+?@\S+?)>/', $text, $matches ) ) {
$markup .= '<a href="mailto:' . $matches[1] . '">' . $matches[1] . '</a>';
$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 .= '<code>' . $element_text . '</code>';
$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 .= '<a href="' . $element_url . '">' . $element_url . '</a>';
$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 .= '<del>' . $matches[1] . '</del>';
$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',
);
}
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