ngModel.NgModelController.$setValidity()

Name of the validator. The validationErrorKey will be assigned to either $error[validationErrorKey] or $pending[validationErrorKey] (for unfulfilled $asyncValidators), so that it is available for data-binding. The validationErrorKey should be in camelCase and will get converted into dash-case for class name. Example: myError will result in ng-valid-my-error and ng-invalid-my-error class and can be bound to as {{someForm.someControl.$error.myError}} .

Whether the current state is valid (true), invalid (false), pending (undefined), or skipped (null). Pending is used for unfulfilled $asyncValidators. Skipped is used by Angular when validators do not run because of parse errors and when $asyncValidators do not run because any of the $validators failed.