Ash Elixir•3y ago

protocol Enumerable not implemented for #Ash.Changeset

I apologize if I abuse the support channel, please tell me if I should take this to #general or #archive-debugging I've ran into this issue on two different resources, and I'll detail both below. The tl;dr is: I define a code_interface for a resource, but when I call the function it fails with protocol Enumerable not implemented for #Ash.Changeset<action_type: :create... at (ash 2.6.27) lib/ash/changeset/changeset.ex:998: Ash.Changeset.cast_params/3 Resource the first I want to generate an "external id" on creation, so I expose a new acton via code_interface.

defmodule Telepai.App.Session do
  attributes do
    integer_primary_key(:id)
    attribute :external_id, :string
    attribute :settings, :string
  end

  actions do
    defaults([:create, :read, :update, :destroy])

    create :new do
      accept([:settings])

      change(fn changeset, _ ->
        now = NaiveDateTime.utc_now() |> NaiveDateTime.to_string()
        external_id = now |> HumanReadableIdentifierGenerator.fetch_human_readable_id!()

        changeset |> Ash.Changeset.change_attribute(:external_id, external_id)
      end)
    end
  end

  code_interface do
    define_for(__MODULE__)
    define(:new)

    # Note: if I don't define :create, compiler complains that 
    # `create/2` and `create!/2` are private or not defined
    define(:create)
  end
end

defmodule Telepai.App.Session do
  attributes do
    integer_primary_key(:id)
    attribute :external_id, :string
    attribute :settings, :string
  end

  actions do
    defaults([:create, :read, :update, :destroy])

    create :new do
      accept([:settings])

      change(fn changeset, _ ->
        now = NaiveDateTime.utc_now() |> NaiveDateTime.to_string()
        external_id = now |> HumanReadableIdentifierGenerator.fetch_human_readable_id!()

        changeset |> Ash.Changeset.change_attribute(:external_id, external_id)
      end)
    end
  end

  code_interface do
    define_for(__MODULE__)
    define(:new)

    # Note: if I don't define :create, compiler complains that 
    # `create/2` and `create!/2` are private or not defined
    define(:create)
  end
end

Then calling it:

> Telepai.App.Session.new!(%{settings: "aaa"})
protocol Enumerable not implemented for #Ash.Changeset<action_type: :create, action: :new, attributes: %{external_id: "pingo-frangimini-51", settings: "aaa"}, relationships: %{}...
...
    (ash 2.6.27) lib/ash/changeset/changeset.ex:998: Ash.Changeset.cast_params/3
    (ash 2.6.27) lib/ash/changeset/changeset.ex:747: Ash.Changeset.do_for_action/4
    (telepai 0.1.0) lib/ash/code_interface.ex:533: Telepai.App.Session.create!/2

> Telepai.App.Session.new!(%{settings: "aaa"})
protocol Enumerable not implemented for #Ash.Changeset<action_type: :create, action: :new, attributes: %{external_id: "pingo-frangimini-51", settings: "aaa"}, relationships: %{}...
...
    (ash 2.6.27) lib/ash/changeset/changeset.ex:998: Ash.Changeset.cast_params/3
    (ash 2.6.27) lib/ash/changeset/changeset.ex:747: Ash.Changeset.do_for_action/4
    (telepai 0.1.0) lib/ash/code_interface.ex:533: Telepai.App.Session.create!/2

I'll continue with the second resource in the comments

3 Replies

ZachDaniel•3y ago

The support forum is exactly where all questions like this should go 🙂 👍 define_for should point at the api module that needs to be called define_for Telepai.App (if that is what your API module is called) Thats also why it was yelling at you about defining create, because it tries to call Api.create(....)

dmitriidOP•3y ago

Resource the second This one is somewhat trickier as it only contains relationships to other resources:

defmodule Telepai.Users.Bookmark do
  actions do
    defaults([:create, :read, :update, :destroy])
  end

  attributes do
    integer_primary_key(:id)
  end

  relationships do
    belongs_to :user, Telepai.Users.User do
      allow_nil?(false)
    end

    belongs_to :history, Telepai.App.History do
      api(Telepai.App)
      allow_nil?(false)
    end
  end

  code_interface do
    define_for(__MODULE__)

    # I tried both deifnitions, but with the same result :)
    define(:new, action: :create, args: [:user, :history])
    define(:create)
  end
end

defmodule Telepai.Users.Bookmark do
  actions do
    defaults([:create, :read, :update, :destroy])
  end

  attributes do
    integer_primary_key(:id)
  end

  relationships do
    belongs_to :user, Telepai.Users.User do
      allow_nil?(false)
    end

    belongs_to :history, Telepai.App.History do
      api(Telepai.App)
      allow_nil?(false)
    end
  end

  code_interface do
    define_for(__MODULE__)

    # I tried both deifnitions, but with the same result :)
    define(:new, action: :create, args: [:user, :history])
    define(:create)
  end
end

Using it:

> Telepai.Users.Bookmark.new(1, 1)                  
** (Protocol.UndefinedError) protocol Enumerable not implemented for #Ash.Changeset<action_type: :create, action: :create, attributes: %{}...
...
    (ash 2.6.27) lib/ash/changeset/changeset.ex:998: Ash.Changeset.cast_params/3
    (ash 2.6.27) lib/ash/changeset/changeset.ex:747: Ash.Changeset.do_for_action/4
    (telepai 0.1.0) lib/ash/code_interface.ex:496: Telepai.Users.Bookmark.create/2

> Telepai.Users.Bookmark.new(1, 1)                  
** (Protocol.UndefinedError) protocol Enumerable not implemented for #Ash.Changeset<action_type: :create, action: :create, attributes: %{}...
...
    (ash 2.6.27) lib/ash/changeset/changeset.ex:998: Ash.Changeset.cast_params/3
    (ash 2.6.27) lib/ash/changeset/changeset.ex:747: Ash.Changeset.do_for_action/4
    (telepai 0.1.0) lib/ash/code_interface.ex:496: Telepai.Users.Bookmark.create/2

Oh my 😄 That's probably the reason 🙂 Ahahaha. YES. I should read the docs more carefully @Zach Daniel thank you!

ZachDaniel•3y ago

My pleasure 😄

Gaming

Programming

protocol Enumerable not implemented for #Ash.Changeset

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