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('/^\[(.*?)(?[^\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 '!['
. $this->escapeHtmlEntities(
$block['text'],
ENT_COMPAT | ENT_SUBSTITUTE
)
. ']('
. $this->escapeHtmlEntities($block['url'], ENT_COMPAT) . ' "'
. $this->escapeHtmlEntities(
$block['title'],
ENT_COMPAT | ENT_SUBSTITUTE
)
. '")
html5 ? '>' : ' />');
}
#---------------------------------------------
# References
#---------------------------------------------
protected function identifyReference($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);
}