When user does not define customPaging fn, slick returns "undefined" text instead of default value - button element (see https://github.com/kenwheeler/slick/blob/master/slick/slick.js#L57 for reference).
Besides, you'll never get "null", because scope.attributeFn is wrapped by angular.
When user does not define customPaging fn, slick returns "undefined" text instead of default value - button element (see https://github.com/kenwheeler/slick/blob/master/slick/slick.js#L57 for reference). Besides, you'll never get "null", because scope.attributeFn is wrapped by angular.