AlgoliaSearch\Client::generateSecuredApiKey PHP Method

    public static function generateSecuredApiKey($privateApiKey, $query, $userToken = null)
    {
        $urlEncodedQuery = '';
        if (is_array($query)) {
            $queryParameters = array();
            if (array_keys($query) !== array_keys(array_keys($query))) {
                // array of query parameters
                $queryParameters = $query;
            } else {
                // array of tags
                $tmp = array();
                foreach ($query as $tag) {
                    if (is_array($tag)) {
                        array_push($tmp, '(' . implode(',', $tag) . ')');
                    } else {
                        array_push($tmp, $tag);
                    }
                }
                $tagFilters = implode(',', $tmp);
                $queryParameters['tagFilters'] = $tagFilters;
            }
            if ($userToken != null && strlen($userToken) > 0) {
                $queryParameters['userToken'] = $userToken;
            }
            $urlEncodedQuery = static::buildQuery($queryParameters);
        } else {
            if (strpos($query, '=') === false) {
                // String of tags
                $queryParameters = array('tagFilters' => $query);
                if ($userToken != null && strlen($userToken) > 0) {
                    $queryParameters['userToken'] = $userToken;
                }
                $urlEncodedQuery = static::buildQuery($queryParameters);
            } else {
                // url encoded query
                $urlEncodedQuery = $query;
                if ($userToken != null && strlen($userToken) > 0) {
                    $urlEncodedQuery = $urlEncodedQuery . '&userToken=' . urlencode($userToken);
                }
            }
        }
        $content = hash_hmac('sha256', $urlEncodedQuery, $privateApiKey) . $urlEncodedQuery;
        return base64_encode($content);
    }

 public function generateSearchSecuredApiKey($key, $params = array())
 {
     return $this->client->generateSecuredApiKey($key, $params);
 }