Myrmyr Posts - Answer Overflow

Myrmyr

•Created by Myrmyr on 9/29/2023 in #support

Forbid all but one field using field policies

Hello, I need to forbid Anonymous actor access to all fields but id and status. Basically it's needed for some calulcations but we don't want him to have access to any other data. So I've tried using policies like this:

  field_policies do
    field_policy :status do
      authorize_if always()
    end

    field_policy :* do
      forbid_if Checks.IsAnonymousActor
      authorize_if always()
    end
  end

  field_policies do
    field_policy :status do
      authorize_if always()
    end

    field_policy :* do
      forbid_if Checks.IsAnonymousActor
      authorize_if always()
    end
  end

But this seems to not be working, probably because for status filed Ash checks policies from both status and :*. Is there any way to achieve that?

4 replies

AEAsh Elixir

•Created by Myrmyr on 7/20/2023 in #support

Ash dropping FilterCheck if there's `authorize_if always()`

Hi, I've got a resource that in it's action has:

authorize_if MyApp.FilterByActorId
authorize_if always()

authorize_if MyApp.FilterByActorId
authorize_if always()

Previously there were other checks instead of always() but we've loosened our constraints. When we've changed it to always() the FilterByActorID stopped applying My question is, is this the intended behaviour or is it a bug?

18 replies

AEAsh Elixir

•Created by Myrmyr on 6/27/2023 in #support

Updating Spark to 1.1.17 breaks Ash.Flow transaction DSL

Ash version: 2.10.2 Spark latest working version: 1.1.16 Spark version that breaks: 1.1.17 Example code:

defmodule MyApp.Flows.ExampleFlow do
  @moduledoc false

  use Ash.Flow

  flow do
    api MyApp.Api

    argument :example_arg, :map do
      allow_nil? false
    end

    returns :some_transaction
  end

  steps do
    # This works
    custom :custom_step_that_do_not_break, MyApp.Flows.Steps.SimpleReturn do
      input %{
        return: arg(:example_arg)
      }
    end

    transaction :some_transaction, MyApp.SomeEntity do
      # This does not work
      custom :custom_step_that_breaks, MyApp.Flows.Steps.SimpleReturn do
        input %{
          return: arg(:example_arg)
        } 
      end
    end
  end
end

defmodule MyApp.Flows.ExampleFlow do
  @moduledoc false

  use Ash.Flow

  flow do
    api MyApp.Api

    argument :example_arg, :map do
      allow_nil? false
    end

    returns :some_transaction
  end

  steps do
    # This works
    custom :custom_step_that_do_not_break, MyApp.Flows.Steps.SimpleReturn do
      input %{
        return: arg(:example_arg)
      }
    end

    transaction :some_transaction, MyApp.SomeEntity do
      # This does not work
      custom :custom_step_that_breaks, MyApp.Flows.Steps.SimpleReturn do
        input %{
          return: arg(:example_arg)
        } 
      end
    end
  end
end

Error message:

== Compilation error in file lib/my_app/flows/example_flow.ex ==
** (CompileError) lib/my_app/flows/example_flow.ex:24: undefined function custom/3 (there is no such import)
    (stdlib 4.1.1) lists.erl:1462: :lists.mapfoldl_1/3
    (ash 2.10.2) expanding macro: Ash.Flow.Dsl.Steps.Transaction.transaction/3

== Compilation error in file lib/my_app/flows/example_flow.ex ==
** (CompileError) lib/my_app/flows/example_flow.ex:24: undefined function custom/3 (there is no such import)
    (stdlib 4.1.1) lists.erl:1462: :lists.mapfoldl_1/3
    (ash 2.10.2) expanding macro: Ash.Flow.Dsl.Steps.Transaction.transaction/3

Didn't know whether this should be reported to Spark or Ash so I'm reporting it here.

3 replies

AEAsh Elixir

•Created by Myrmyr on 5/9/2023 in #support

Prevent action's changes from being run on `AshPhoenix.Form.validate`

Hello, I have an resource A that has a filed let's say capacity , belongs_to relationship to B resource and create action that has a change LoadDefaultFromRelationship . This change basically fetches the capacity from B resource if none was given in the create action params for A. The problem with such approach is that every time we invoke the AshPhoenix.Form.validate it makes a query to the database for this default value. Is there any way to prevent this change being run on AshPhoenix.Form.validate but still apply on create action?

7 replies

AEAsh Elixir

•Created by Myrmyr on 4/3/2023 in #support

`Ash.Type.NewType` defines multiple GraphQL types with the same name.

I have the following custom type

defmodule MyApp.Types.DayOfWeek do
  @moduledoc false

  use Ash.Type.NewType,
    subtype_of: :atom,
    constraints: [one_of: [:monday, :tuesday, :wednesday, :thursday, :friday, :saturday, :sunday]]

  def graphql_input_type(_), do: :day_of_week
  def graphql_type, do: :day_of_week
  def graphql_type(_), do: :day_of_week
end

defmodule MyApp.Types.DayOfWeek do
  @moduledoc false

  use Ash.Type.NewType,
    subtype_of: :atom,
    constraints: [one_of: [:monday, :tuesday, :wednesday, :thursday, :friday, :saturday, :sunday]]

  def graphql_input_type(_), do: :day_of_week
  def graphql_type, do: :day_of_week
  def graphql_type(_), do: :day_of_week
end

That is used in two resources

defmodule ResourceA do
  ...
  attributes do
    ...
    attribute :days_of_week, {:array, MyApp.Types.DayOfWeek} 
  end
end


defmodule ResourceB do
  ...
  attributes do
    ...
    attribute :day_of_week, MyApp.Types.DayOfWeek}
  end

  relationships do
    belongs_to :a_resource, ResourceA, allow_nil?: false
  end
end

defmodule ResourceA do
  ...
  attributes do
    ...
    attribute :days_of_week, {:array, MyApp.Types.DayOfWeek} 
  end
end


defmodule ResourceB do
  ...
  attributes do
    ...
    attribute :day_of_week, MyApp.Types.DayOfWeek}
  end

  relationships do
    belongs_to :a_resource, ResourceA, allow_nil?: false
  end
end

Also I've defined a Scalar and imported it to schema

  scalar :day_of_week do
    parse(&parse_day_of_week/1)
    serialize(& &1)
  end

  defp parse_day_of_week(%Absinthe.Blueprint.Input.String{value: value}) do
    case MyApp.Types.DayOfWeek.cast_input(value, []) do
      {:ok, value} -> {:ok, value}
      _ -> :error
    end
  end

  scalar :day_of_week do
    parse(&parse_day_of_week/1)
    serialize(& &1)
  end

  defp parse_day_of_week(%Absinthe.Blueprint.Input.String{value: value}) do
    case MyApp.Types.DayOfWeek.cast_input(value, []) do
      {:ok, value} -> {:ok, value}
      _ -> :error
    end
  end

20 replies

AEAsh Elixir

•Created by Myrmyr on 3/16/2023 in #support

Embed `has_one` relationship into resource

Let's say I have a resource A. It has relationship:

  relationships do
    has_many :a_version, Ash.Api.AVersion do
      sort created_at: :desc
    end
  end

  relationships do
    has_many :a_version, Ash.Api.AVersion do
      sort created_at: :desc
    end
  end

which holds some fields that should be versioned if any changes happen, it has at least one :a_version Let's say the AVersion has the a :price attribute. We can define the manual fake "has_one" relationship, by making a query that takes the latest version of AVersion. Now, here's question. Is there any way to embed the fields from the latest AVersion from the fake "has_one" manual relationship into A so that they can be: - Accessed at top-level like A.price - Loaded automatically as if they were attributes of the A itself?

38 replies

AEAsh Elixir

•Created by Myrmyr on 2/9/2023 in #support

Ash stopped working with ExMachina. Ash 2.5.10

Hello, I've been using Ash with ExMachina successfully up to this point. Recently I've wanted to upgrade Ash from 2.5.9 to 2.6.0, alongside AshPostgres from 1.3.3 to 1.3.8. I've tested combinations of different Ash and AshPostgres combinations to narrow down the issue. It appears to be caused by Ash 2.5.10. Specifically this commit https://github.com/ash-project/ash/commit/2787b5074b8b339057af6f0bc4ee3db5abf7c60d Our factory:

defmodule MyApp.Factory do
  @moduledoc false
  use ExMachina.Ecto, repo: MyApp.Repo

 def resource_factory do
    %MyApp.Resource{
      id: Ecto.UUID.generate(),
      name: sequence(:name, &"Resource #{&1}"),
      ...
    }
  end

defmodule MyApp.Factory do
  @moduledoc false
  use ExMachina.Ecto, repo: MyApp.Repo

 def resource_factory do
    %MyApp.Resource{
      id: Ecto.UUID.generate(),
      name: sequence(:name, &"Resource #{&1}"),
      ...
    }
  end

When I try to do insert(:resource, some_field: "some_value) I get the following error

** (UndefinedFunctionError) function Ash.NotLoaded.__schema__/0 is undefined or private
    (ash 2.6.0) Ash.NotLoaded.__schema__()
    iex:1: (file)

** (UndefinedFunctionError) function Ash.NotLoaded.__schema__/0 is undefined or private
    (ash 2.6.0) Ash.NotLoaded.__schema__()
    iex:1: (file)

Is there any possibility to bring back the support for ExMachina?

29 replies

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