How can I access the resource that a policy applies to, within the rule?

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1

Hi,

I’m trying to filter in Ash Policy :read.
How can I access the resource that the policy applies to from the rule?
Is there a way to access the contract in question when this rule runs?
E.g check if contract.client.email == actor.email.

defmodule MyApp.Policies.IsContractRecipient do
  use Ash.Policy.FilterCheck

  require Ash.Query
  import Ash.Filter.TemplateHelpers, only: [actor: 1]

  def filter(_options) do
    # Only allow to read contracts where the actor is the recipient
    # Eg. contract.client.email == actor(:email)
    Ash.Query.expr(contract.client.email == ^actor(:email))
  end
end
2

Ash.Policy.FilterCheckWithContext — ash v2.18.2 gets the context which also holds the resource.

1 Like
3

actually, the problem was two fold:

  1. We had used the policy in a contract resource and had prefixed client.email with contract
  2. We hadn’t passed in load option to load client when reading contracts since policy needs preloaded data to be present to pass.

@barnabasJ does FilterCheckWithContext solve issue #2 ?

4

Filter checks are attached to the query, so in case of a read, it would be part of the where clause if used with AshPostgres. Therefore, you don’t need to explicitly tell Ash to load the data, it will do it itself.