Why would you need an async validation? Can you please give an example?

@DAB0mB Great question! In my application I use the alanning:roles package, and in my ui-router routes definition, I have a resolve function that uses $auth.requireValidUser to verify that a user has the admin role before giving them access to the admin portion of the site. I have a subscription set up to send me the current user's document, which includes the roles field used by the roles package. However, Meteor automatically publishes the user's profile, username, and emails fields. Thus, for a brief moment during app startup, the document returned by Meteor.user(), will exist and have a few fields, but it will not yet have all of them. This matters because a naive requireValidUser validator like user => Roles.userIsInRole(user, 'admin') will sometimes fail on startup if the user document does not have the roles field loaded yet.

There are a couple ways of solving this problem. One is to change the logic in $$Auth.$awaitUser to also wait for the user to have a roles field. This approach is too specific because it would break code that does not use the roles package. Another way would be to use asynchronous validators to wait to validate the user until it has the roles field. It is a very complex situation, but that is my use case for wanting asynchronous validators. However, if you have a recommendation for another way to solve this problem, I would love to hear it!

@Urigo @DAB0mB Have you decided whether this pull request will be merged or not? Is there anything I can do to increase its likelihood of being merged?

@canac maybe let's schedule a meeting on Hangouts?
you can ping me on gmail

What happend with this PR ?

@santiq Nothing, yet. Do you need this feature too?

Yes, I need this too as I'm having the same issue

There were merge conflicts, so I just rebased off of master to fix those.

well, that took a while for us :)

sorry about that @canac