+ $contact = Contact::getDetailsByAddr($author, 0);
+ if (!empty($contact['network'])) {
+ $prefix = 'urn:X-' . $contact['network'] . ':';
+ } else {
+ // This fallback should happen most unlikely
+ $prefix = 'urn:X-dspr:';
+ }
+
+ $author_parts = explode('@', $author);
+
+ return $prefix . $author_parts[1] . ':' . $author_parts[0] . ':'. $guid;