portainer/app/services/formValidator.js

angular.module('portainer.services')
.factory('FormValidator', [function FormValidatorFactory() {
  'use strict';

  var validator = {};

  validator.validateAccessControl = function(accessControlData, isAdmin) {
    if (!accessControlData.AccessControlEnabled) {
      return '';
    }

    if (isAdmin && accessControlData.Ownership === 'restricted' &&
    accessControlData.AuthorizedUsers.length === 0 &&
    accessControlData.AuthorizedTeams.length === 0) {
      return 'You must specify at least one team or user.';
    } else if (!isAdmin && accessControlData.Ownership === 'restricted' &&
    accessControlData.AuthorizedTeams.length === 0) {
      return 'You must specify at least a team.';
    }
    return '';
  };

  return validator;
}]);