+ /**
+ * Rename or delete a tag across all links.
+ *
+ * @param string $from Tag to rename
+ * @param string $to New tag. If none is provided, the from tag will be deleted
+ *
+ * @return array|bool List of altered links or false on error
+ */
+ public function renameTag($from, $to)
+ {
+ if (empty($from)) {
+ return false;
+ }
+ $delete = empty($to);
+ // True for case-sensitive tag search.
+ $linksToAlter = $this->filterSearch(['searchtags' => $from], true);
+ foreach ($linksToAlter as $key => &$value) {
+ $tags = preg_split('/\s+/', trim($value['tags']));
+ if (($pos = array_search($from, $tags)) !== false) {
+ if ($delete) {
+ unset($tags[$pos]); // Remove tag.
+ } else {
+ $tags[$pos] = trim($to);
+ }
+ $value['tags'] = trim(implode(' ', array_unique($tags)));
+ $this[$value['id']] = $value;
+ }
+ }
+
+ return $linksToAlter;
+ }
+