if ($ajax = Yii::$app->request->isAjax){
            // get the ajax post
            $workDaysInput = Yii::$app->request->post('input');

            // map over the items
            $workDays = collect($workDaysInput)
                ->map(function ($record){

                    $identification = $record['identification'];

                    $re = '/^work_days\[(.*?)\]/';
                    $str = $identification;

                    preg_match_all($re, $str, $matches, PREG_SET_ORDER, 0);

                    $recordId   = preg_replace('/\D/','',$identification);
                    $recordType = $matches[0][1];

                    $record['type'] = $recordType;
                    $record['id'] = $recordId;

                    // change record and populate with id and type
                    return $record;
                })
                // simply sort by type for easier search
                ->keyBy('type');

        }