/**
* Tags this session with the given tag.
*
* Note that third-party libraries might also tag your session. Therefore it is
* recommended to use namespaced tags such as "Acme-Demo-MySpecialTag".
*
* @param string $tag The tag – must match be a valid cache frontend tag
* @return void
* @throws Exception\SessionNotStartedException
* @throws \InvalidArgumentException
* @api
*/
public function addTag($tag)
{
if ($this->started !== true) {
throw new Exception\SessionNotStartedException('Tried to tag a session which has not been started yet.', 1355143533);
}
if (!$this->metaDataCache->isValidTag($tag)) {
throw new \InvalidArgumentException(sprintf('The tag used for tagging session %s contained invalid characters. Make sure it matches this regular expression: "%s"', $this->sessionIdentifier, FrontendInterface::PATTERN_TAG));
}
if (!in_array($tag, $this->tags)) {
$this->tags[] = $tag;
}
}
