$title, 'excerpt' => self::plainLine($excerpt, self::EXCERPT_MAX), 'body' => self::toHtml($body)];
}
/** Plain single line: tags removed, whitespace collapsed, bounded. */
public static function plainLine(string $text, int $max): string
{
$text = (string) preg_replace('/<[^>]*>?/u', '', $text);
$text = trim((string) preg_replace('/\s+/u', ' ', $text));
return mb_substr($text, 0, $max);
}
public static function toHtml(string $text): string
{
$text = mb_substr(trim($text), 0, self::BODY_MAX);
if ($text === '') {
return '';
}
$html = '';
$para = [];
$list = [];
$flush = static function () use (&$html, &$para, &$list): void {
if ($para !== []) {
$html .= '' . implode(' ', $para) . "
\n";
$para = [];
}
if ($list !== []) {
$html .= "\n- " . implode("
\n- ", $list) . "
\n
\n";
$list = [];
}
};
foreach (explode("\n", $text) as $line) {
$line = trim($line);
if ($line === '') {
$flush();
} elseif (preg_match('/^(#{1,3})\s+(.+)$/u', $line, $m)) {
$flush();
$level = strlen($m[1]) <= 2 ? 2 : 3;
$html .= "" . self::esc($m[2]) . "\n";
} elseif (preg_match('/^[-*]\s+(.+)$/u', $line, $m)) {
if ($para !== []) {
$flush();
}
$list[] = self::esc($m[1]);
} else {
if ($list !== []) {
$flush();
}
$para[] = self::esc($line);
}
}
$flush();
return rtrim($html);
}
private static function esc(string $s): string
{
return htmlspecialchars($s, ENT_QUOTES | ENT_SUBSTITUTE, 'UTF-8');
}
}