Subscription with Authorization: Skip trigger if condition isn't met

问题

I have a Phoenix web application and am using Absinthe for subscriptions that are triggered whenever a new Comment is added to a Topic. I am trying to send a subscription only if the user is a member of a topic, and otherwise not send something at all.

So far I've tried playing with config as mentioned in the Subscription docs but it seems like that it is only executed when creating the subscription and not when it is triggered. I'm hoping it is something as simple as:

resolve fn comment, _, %{context: context} ->
  if User.member_of?(context.user, commment.topic) do
    {:ok, comment}
  else
    :noreply
  end
end

For now, I'm just returning {:ok, nil} but I'm hoping there is a better way to achieve this.

来源：https://stackoverflow.com/questions/54894293/subscription-with-authorization-skip-trigger-if-condition-isnt-met