How to create a Reactive Data Source to Resove a Route

I need to retrieve a specific field from the users collections, How can I get it just like the way I can get the _id from an user with Meteor.userId() function ?

I nee to know so I can resolve routes from angular.

$stateProvider.state('mystate', {
    resolve: {
      adminUser($q) {
        //so I can resolve a route in angular like this
        if (user.isAdmin) {
          return $q.resolve();
        } else {
          return $q.reject();

I would appreciate any help, and any recommendation if it is a better way to achieve the same result