So you have two options here.
Use the arguments to look up related info
The first one is to use the input arguments to determine the related thing, and then operate on that information.
For example:
defmodule YourApp.Checks.MatchesDrinkingAge do
use Ash.Policy.SimpleCheck
def match?(actor, %{source: %Ash.Changeset{} = changeset}, _opts) do
country_id = Ash.Changeset.get_argument(changeset, :country_id)
# lookup the country id, and return `true` or `false` depending
end
end
Put the action on the thing that controls the rules
This is probably not what you want in this case, but can be useful to simplify
# on Country
create :add_beer do
# create the beer in a hook
...
end
It’s actually a little bit inconvenient to authorize data creation when compared with our other check types, and I would really like to build up some more tools for this kind of thing.
But, although slightly more verbose than we’d prefer, you can ultimately do “anything you want” in simple checks, and those should allow for any authorization logic you need in this case.
