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mirror of https://github.com/erusev/parsedown.git synced 2023-08-10 21:13:06 +03:00
parsedown/Parsedown.php
2014-01-22 21:28:29 +02:00

1039 lines
19 KiB
PHP
Executable File

<?php
#
#
# Parsedown
# http://parsedown.org
#
# (c) Emanuil Rusev
# http://erusev.com
#
# For the full license information, please view the LICENSE file that was
# distributed with this source code.
#
#
class Parsedown
{
#
# Multiton (http://en.wikipedia.org/wiki/Multiton_pattern)
#
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
#
private $breaks_enabled = false;
function set_breaks_enabled($breaks_enabled)
{
$this->breaks_enabled = $breaks_enabled;
return $this;
}
#
# Fields
#
private $reference_map = array();
#
# Public Methods
#
function parse($text)
{
# removes \r characters
$text = str_replace("\r\n", "\n", $text);
$text = str_replace("\r", "\n", $text);
# replaces tabs with spaces
$text = str_replace("\t", ' ', $text);
# ~
$text = trim($text, "\n");
$lines = explode("\n", $text);
$text = $this->parse_block_elements($lines);
$text = rtrim($text, "\n");
return $text;
}
#
# Private Methods
#
private function parse_block_elements(array $lines, $context = '')
{
$elements = array();
$element = array(
'type' => '',
);
foreach ($lines as $line)
{
# fenced elements
switch ($element['type'])
{
case 'fenced block':
if ( ! isset($element['closed']))
{
if (preg_match('/^[ ]*'.$element['fence'][0].'{3,}[ ]*$/', $line))
{
$element['closed'] = true;
}
else
{
$element['text'] !== '' and $element['text'] .= "\n";
$element['text'] .= $line;
}
continue 2;
}
break;
case 'block-level markup':
if ( ! isset($element['closed']))
{
if (strpos($line, $element['start']) !== false) # opening tag
{
$element['depth']++;
}
if (strpos($line, $element['end']) !== false) # closing tag
{
$element['depth'] > 0
? $element['depth']--
: $element['closed'] = true;
}
$element['text'] .= "\n".$line;
continue 2;
}
break;
}
# *
$deindented_line = ltrim($line);
if ($deindented_line === '')
{
$element['interrupted'] = true;
continue;
}
# composite elements
switch ($element['type'])
{
case 'blockquote':
if ( ! isset($element['interrupted']))
{
$line = preg_replace('/^[ ]*>[ ]?/', '', $line);
$element['lines'] []= $line;
continue 2;
}
break;
case 'li':
if (preg_match('/^([ ]{0,3})(\d+[.]|[*+-])[ ](.*)/', $line, $matches))
{
if ($element['indentation'] !== $matches[1])
{
$element['lines'] []= $line;
}
else
{
unset($element['last']);
$elements []= $element;
$element = array(
'type' => 'li',
'indentation' => $matches[1],
'last' => true,
'lines' => array(
preg_replace('/^[ ]{0,4}/', '', $matches[3]),
),
);
}
continue 2;
}
if (isset($element['interrupted']))
{
if ($line[0] === ' ')
{
$element['lines'] []= '';
$line = preg_replace('/^[ ]{0,4}/', '', $line);
$element['lines'] []= $line;
unset($element['interrupted']);
continue 2;
}
}
else
{
$line = preg_replace('/^[ ]{0,4}/', '', $line);
$element['lines'] []= $line;
continue 2;
}
break;
}
# indentation sensitive types
switch ($line[0])
{
case ' ':
# code block
if (isset($line[3]) and $line[3] === ' ' and $line[2] === ' ' and $line[1] === ' ')
{
$code_line = substr($line, 4);
if ($element['type'] === 'code block')
{
if (isset($element['interrupted']))
{
$element['text'] .= "\n";
unset ($element['interrupted']);
}
$element['text'] .= "\n".$code_line;
}
else
{
$elements []= $element;
$element = array(
'type' => 'code block',
'text' => $code_line,
);
}
continue 2;
}
break;
case '#':
# atx heading (#)
if (isset($line[1]))
{
$elements []= $element;
$level = 1;
while (isset($line[$level]) and $line[$level] === '#')
{
$level++;
}
$element = array(
'type' => 'heading',
'text' => trim($line, '# '),
'level' => $level,
);
continue 2;
}
break;
case '-':
case '=':
# setext heading
if ($element['type'] === 'paragraph' and isset($element['interrupted']) === false)
{
$chopped_line = rtrim($line);
$i = 1;
while (isset($chopped_line[$i]))
{
if ($chopped_line[$i] !== $line[0])
{
break 2;
}
$i++;
}
$element['type'] = 'heading';
$element['level'] = $line[0] === '-' ? 2 : 1;
continue 2;
}
break;
}
# indentation insensitive types
switch ($deindented_line[0])
{
case '<':
$position = strpos($deindented_line, '>');
if ($position > 1) # tag
{
$name = substr($deindented_line, 1, $position - 1);
$name = rtrim($name);
if (substr($name, -1) === '/')
{
$self_closing = true;
$name = substr($name, 0, -1);
}
$position = strpos($name, ' ');
if ($position)
{
$name = substr($name, 0, $position);
}
if ( ! ctype_alpha($name))
{
break;
}
if (in_array($name, $this->inline_tags))
{
break;
}
$elements []= $element;
if (isset($self_closing))
{
$element = array(
'type' => 'self-closing tag',
'text' => $deindented_line,
);
unset($self_closing);
continue 2;
}
$element = array(
'type' => 'block-level markup',
'text' => $deindented_line,
'start' => '<'.$name.'>',
'end' => '</'.$name.'>',
'depth' => 0,
);
if (strpos($deindented_line, $element['end']))
{
$element['closed'] = true;
}
continue 2;
}
break;
case '>':
# quote
if (preg_match('/^>[ ]?(.*)/', $deindented_line, $matches))
{
$elements []= $element;
$element = array(
'type' => 'blockquote',
'lines' => array(
$matches[1],
),
);
continue 2;
}
break;
case '[':
# reference
if (preg_match('/^\[(.+?)\]:[ ]*(.+?)(?:[ ]+[\'"](.+?)[\'"])?[ ]*$/', $deindented_line, $matches))
{
$label = strtolower($matches[1]);
$this->reference_map[$label] = array(
'»' => trim($matches[2], '<>'),
);
if (isset($matches[3]))
{
$this->reference_map[$label]['#'] = $matches[3];
}
continue 2;
}
break;
case '`':
case '~':
# fenced code block
if (preg_match('/^([`]{3,}|[~]{3,})[ ]*(\S+)?[ ]*$/', $deindented_line, $matches))
{
$elements []= $element;
$element = array(
'type' => 'fenced block',
'text' => '',
'fence' => $matches[1],
);
isset($matches[2]) and $element['language'] = $matches[2];
continue 2;
}
break;
case '*':
case '+':
case '-':
case '_':
# hr
if (preg_match('/^([-*_])([ ]{0,2}\1){2,}[ ]*$/', $deindented_line))
{
$elements []= $element;
$element = array(
'type' => 'hr',
);
continue 2;
}
# li
if (preg_match('/^([ ]*)[*+-][ ](.*)/', $line, $matches))
{
$elements []= $element;
$element = array(
'type' => 'li',
'ordered' => false,
'indentation' => $matches[1],
'last' => true,
'lines' => array(
preg_replace('/^[ ]{0,4}/', '', $matches[2]),
),
);
continue 2;
}
}
# li
if ($deindented_line[0] <= '9' and $deindented_line[0] >= '0' and preg_match('/^([ ]*)\d+[.][ ](.*)/', $line, $matches))
{
$elements []= $element;
$element = array(
'type' => 'li',
'ordered' => true,
'indentation' => $matches[1],
'last' => true,
'lines' => array(
preg_replace('/^[ ]{0,4}/', '', $matches[2]),
),
);
continue;
}
# paragraph
if ($element['type'] === 'paragraph')
{
if (isset($element['interrupted']))
{
$elements []= $element;
$element['text'] = $line;
unset($element['interrupted']);
}
else
{
$this->breaks_enabled and $element['text'] .= ' ';
$element['text'] .= "\n".$line;
}
}
else
{
$elements []= $element;
$element = array(
'type' => 'paragraph',
'text' => $line,
);
}
}
$elements []= $element;
unset($elements[0]);
#
# ~
#
$markup = '';
foreach ($elements as $element)
{
switch ($element['type'])
{
case 'paragraph':
$text = $this->parse_span_elements($element['text']);
if ($context === 'li' and $markup === '')
{
if (isset($element['interrupted']))
{
$markup .= "\n".'<p>'.$text.'</p>'."\n";
}
else
{
$markup .= $text;
}
}
else
{
$markup .= '<p>'.$text.'</p>'."\n";
}
break;
case 'blockquote':
$text = $this->parse_block_elements($element['lines']);
$markup .= '<blockquote>'."\n".$text.'</blockquote>'."\n";
break;
case 'code block':
$text = htmlspecialchars($element['text'], ENT_NOQUOTES, 'UTF-8');
$markup .= '<pre><code>'.$text.'</code></pre>'."\n";
break;
case 'fenced block':
$text = htmlspecialchars($element['text'], ENT_NOQUOTES, 'UTF-8');
$markup .= '<pre><code';
isset($element['language']) and $markup .= ' class="language-'.$element['language'].'"';
$markup .= '>'.$text.'</code></pre>'."\n";
break;
case 'heading':
$text = $this->parse_span_elements($element['text']);
$markup .= '<h'.$element['level'].'>'.$text.'</h'.$element['level'].'>'."\n";
break;
case 'hr':
$markup .= '<hr />'."\n";
break;
case 'li':
if (isset($element['ordered'])) # first
{
$list_type = $element['ordered'] ? 'ol' : 'ul';
$markup .= '<'.$list_type.'>'."\n";
}
if (isset($element['interrupted']) and ! isset($element['last']))
{
$element['lines'] []= '';
}
$text = $this->parse_block_elements($element['lines'], 'li');
$markup .= '<li>'.$text.'</li>'."\n";
isset($element['last']) and $markup .= '</'.$list_type.'>'."\n";
break;
case 'block-level markup':
$markup .= $element['text']."\n";
break;
default:
$markup .= $element['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]);
$element['!'] and $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('&', '&amp;', $element['»']);
$element['»'] = str_replace('<', '&lt;', $element['»']);
if ($element['!'])
{
$markup .= '<img alt="'.$element['a'].'" src="'.$element['»'].'"';
isset($element['#']) and $markup .= ' title="'.$element['#'].'"';
$markup .= ' />';
}
else
{
$element['a'] = $this->parse_span_elements($element['a'], $markers);
$markup .= '<a href="'.$element['»'].'"';
isset($element['#']) and $markup .= ' title="'.$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 .= '&amp;';
$offset = 1;
}
break;
case '*':
case '_':
if ($text[1] === $closest_marker and preg_match($this->strong_regex[$closest_marker], $text, $matches))
{
$matches[1] = $this->parse_span_elements($matches[1], $markers);
$markup .= '<strong>'.$matches[1].'</strong>';
}
elseif (preg_match($this->em_regex[$closest_marker], $text, $matches))
{
$matches[1] = $this->parse_span_elements($matches[1], $markers);
$markup .= '<em>'.$matches[1].'</em>';
}
elseif ($text[1] === $closest_marker and preg_match($this->strong_em_regex[$closest_marker], $text, $matches))
{
$matches[2] = $this->parse_span_elements($matches[2], $markers);
$matches[1] and $matches[1] = $this->parse_span_elements($matches[1], $markers);
$matches[3] and $matches[3] = $this->parse_span_elements($matches[3], $markers);
$markup .= '<strong>'.$matches[1].'<em>'.$matches[2].'</em>'.$matches[3].'</strong>';
}
elseif (preg_match($this->em_strong_regex[$closest_marker], $text, $matches))
{
$matches[2] = $this->parse_span_elements($matches[2], $markers);
$matches[1] and $matches[1] = $this->parse_span_elements($matches[1], $markers);
$matches[3] and $matches[3] = $this->parse_span_elements($matches[3], $markers);
$markup .= '<em>'.$matches[1].'<strong>'.$matches[2].'</strong>'.$matches[3].'</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('&', '&amp;', $element_url);
$element_url = str_replace('<', '&lt;', $element_url);
$markup .= '<a href="'.$element_url.'">'.$element_url.'</a>';
$offset = strlen($matches[0]);
}
elseif (preg_match('/^<\/?\w.*?>/', $text, $matches))
{
$markup .= $matches[0];
$offset = strlen($matches[0]);
}
else
{
$markup .= '&lt;';
$offset = 1;
}
}
else
{
$markup .= '&lt;';
$offset = 1;
}
break;
case '\\':
if (in_array($text[1], $this->special_characters))
{
$markup .= $text[1];
$offset = 2;
}
else
{
$markup .= '\\';
$offset = 1;
}
break;
case '`':
if (preg_match('/^`(.+?)`/', $text, $matches))
{
$element_text = $matches[1];
$element_text = htmlspecialchars($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/i', $text, $matches))
{
$element_url = $matches[0];
$element_url = str_replace('&', '&amp;', $element_url);
$element_url = str_replace('<', '&lt;', $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;
}
#
# Read-only
#
private $inline_tags = array(
'a', 'abbr', 'acronym', 'b', 'bdo', 'big', 'br', 'button',
'cite', 'code', 'dfn', 'em', 'i', 'img', 'input', 'kbd',
'label', 'map', 'object', 'q', 'samp', 'script', 'select', 'small',
'span', 'strong', 'sub', 'sup', 'textarea', 'tt', 'var',
);
private $special_characters = array('\\', '`', '*', '_', '{', '}', '[', ']', '(', ')', '>', '#', '+', '-', '.', '!');
# ~
private $strong_regex = array(
'*' => '/^[*]{2}([^*]+?)[*]{2}(?![*])/s',
'_' => '/^__([^_]+?)__(?!_)/s',
);
private $em_regex = array(
'*' => '/^[*]([^*]+?)[*](?![*])/s',
'_' => '/^_([^_]+?)[_](?![_])\b/s',
);
private $strong_em_regex = array(
'*' => '/^[*]{2}(.*?)[*](.+?)[*](.*?)[*]{2}/s',
'_' => '/^__(.*?)_(.+?)_(.*?)__/s',
);
private $em_strong_regex = array(
'*' => '/^[*](.*?)[*]{2}(.+?)[*]{2}(.*?)[*]/s',
'_' => '/^_(.*?)__(.+?)__(.*?)_/s',
);
}