+
+ /**
+ * @brief Pull out all #hashtags and @person tags from $string.
+ *
+ * We also get @person@domain.com - which would make
+ * the regex quite complicated as tags can also
+ * end a sentence. So we'll run through our results
+ * and strip the period from any tags which end with one.
+ * Returns array of tags found, or empty array.
+ *
+ * @param string $string Post content
+ *
+ * @return array List of tag and person names
+ */
+ public static function getTags($string)
+ {
+ $ret = [];
+
+ // Convert hashtag links to hashtags
+ $string = preg_replace('/#\[url\=([^\[\]]*)\](.*?)\[\/url\]/ism', '#$2', $string);
+
+ // ignore anything in a code block
+ $string = preg_replace('/\[code.*?\].*?\[\/code\]/sm', '', $string);
+
+ // Force line feeds at bbtags
+ $string = str_replace(['[', ']'], ["\n[", "]\n"], $string);
+
+ // ignore anything in a bbtag
+ $string = preg_replace('/\[(.*?)\]/sm', '', $string);
+
+ // Match full names against @tags including the space between first and last
+ // We will look these up afterward to see if they are full names or not recognisable.
+
+ if (preg_match_all('/(@[^ \x0D\x0A,:?]+ [^ \x0D\x0A@,:?]+)([ \x0D\x0A@,:?]|$)/', $string, $matches)) {
+ foreach ($matches[1] as $match) {
+ if (strstr($match, ']')) {
+ // we might be inside a bbcode color tag - leave it alone
+ continue;
+ }
+
+ if (substr($match, -1, 1) === '.') {
+ $ret[] = substr($match, 0, -1);
+ } else {
+ $ret[] = $match;
+ }
+ }
+ }
+
+ // Otherwise pull out single word tags. These can be @nickname, @first_last
+ // and #hash tags.
+
+ if (preg_match_all('/([!#@][^\^ \x0D\x0A,;:?]+)([ \x0D\x0A,;:?]|$)/', $string, $matches)) {
+ foreach ($matches[1] as $match) {
+ if (strstr($match, ']')) {
+ // we might be inside a bbcode color tag - leave it alone
+ continue;
+ }
+ if (substr($match, -1, 1) === '.') {
+ $match = substr($match,0,-1);
+ }
+ // ignore strictly numeric tags like #1
+ if ((strpos($match, '#') === 0) && ctype_digit(substr($match, 1))) {
+ continue;
+ }
+ // try not to catch url fragments
+ if (strpos($string, $match) && preg_match('/[a-zA-z0-9\/]/', substr($string, strpos($string, $match) - 1, 1))) {
+ continue;
+ }
+ $ret[] = $match;
+ }
+ }
+
+ return $ret;
+ }