fummmp:

Hey guys, I’m dipping my toes into Ash and try to build a small thing, but now I’m stuck. I created a resource and a relationship. I want to create the resource, but the relationship can be empty. But when I try to create the resource, I get this error:

iex(5)> Inventizr.Inventory.Item |> Ash.Changeset.for_create(:new, %{model: "MacBook", brand: "Apple"}) |> Inventizr.Inventory.create!()
[debug] QUERY OK db=2.3ms idle=1636.8ms
begin []
[debug] QUERY OK db=2.4ms
rollback []
** (UndefinedFunctionError) function Ash.NotLoaded.__changeset__/0 is undefined or private
    (ash 2.5.10) Ash.NotLoaded.__changeset__()
    (ecto 3.9.4) lib/ecto/changeset.ex:409: Ecto.Changeset.change/2
    (ecto 3.9.4) lib/ecto/changeset/relation.ex:173: Ecto.Changeset.Relation.do_change/4
    (ecto 3.9.4) lib/ecto/changeset/relation.ex:335: Ecto.Changeset.Relation.single_change/5
    (ecto 3.9.4) lib/ecto/changeset/relation.ex:165: Ecto.Changeset.Relation.change/3
...

The resource is defined as:

defmodule Inventizr.Inventory.Item do
  use Ash.Resource,
    data_layer: AshPostgres.DataLayer

  attributes do
    uuid_primary_key :id

    attribute :brand, :string
    attribute :model, :string

    attribute :status, :atom do
      constraints one_of: [:available, :in_use, :defect, :unavailable]
      default :available
      allow_nil? false
    end
  end

  relationships do
    belongs_to :user, Inventizr.Accounts.User do
      api Inventizr.Accounts
      allow_nil? true
    end
  end
end

And the corresponding relation:

  attributes do
    uuid_primary_key :id
    attribute :name, :string
  end

  relationships do
    has_many :items, Inventizr.Inventory.Item do
      api Inventizr.Inventory
    end
  end
end

I can’t figure out, what I’m doing wrong, because it works like this in the getting started guide: https://ash-hq.org/docs/guides/ash/latest/tutorials/get-started#working-with-relationships . I’m sure I’m missing something obvious…

frankdugan3:

Welcome! 👋

Is the first resource the full definition?

ZachDaniel:

…perhaps I broke something with the relationship -> assoc interop??

ZachDaniel:

<@245625838035271680> can you post more of the stacktrace?

ZachDaniel:

<@433654314175692800> have you tried out your app against the new branch with this interop?

ZachDaniel:

sorry, the new release 🙂

ZachDaniel:

not on a branch

frankdugan3:

Not the large app. The small app I’m working on that’s up to date, don’t think I have any belongs_to that can be nil. Otherwise, haven’t noticed any problems yet .

ZachDaniel:

welp

ZachDaniel:

ash_postgres tests are failing with the new ash changes, oops

ZachDaniel:

with that same error

frankdugan3:

Ooh, ouch! lol

ZachDaniel:

will fix now

fummmp:

Sure

** (UndefinedFunctionError) function Ash.NotLoaded.__changeset__/0 is undefined or private
    (ash 2.5.10) Ash.NotLoaded.__changeset__()
    (ecto 3.9.4) lib/ecto/changeset.ex:409: Ecto.Changeset.change/2
    (ecto 3.9.4) lib/ecto/changeset/relation.ex:173: Ecto.Changeset.Relation.do_change/4
    (ecto 3.9.4) lib/ecto/changeset/relation.ex:335: Ecto.Changeset.Relation.single_change/5
    (ecto 3.9.4) lib/ecto/changeset/relation.ex:165: Ecto.Changeset.Relation.change/3
    (ecto 3.9.4) lib/ecto/changeset/relation.ex:542: anonymous fn/4 in Ecto.Changeset.Relation.surface_changes/3
    (elixir 1.14.3) lib/enum.ex:2468: Enum."-reduce/3-lists^foldl/2-0-"/3
    (ecto 3.9.4) lib/ecto/changeset/relation.ex:529: Ecto.Changeset.Relation.surface_changes/3
    (ecto 3.9.4) lib/ecto/repo/schema.ex:336: Ecto.Repo.Schema.do_insert/4
    (ash_postgres 1.3.3) lib/data_layer.ex:1018: AshPostgres.DataLayer.create/2
    (ash 2.5.10) lib/ash/actions/create.ex:415: anonymous fn/8 in Ash.Actions.Create.as_requests/5
    (ash 2.5.10) lib/ash/changeset/changeset.ex:1588: Ash.Changeset.run_around_actions/2
    (ash 2.5.10) lib/ash/actions/create.ex:317: anonymous fn/9 in Ash.Actions.Create.as_requests/5
    (ash 2.5.10) lib/ash/engine/request.ex:1028: Ash.Engine.Request.do_try_resolve_local/4
    (ash 2.5.10) lib/ash/engine/request.ex:282: Ash.Engine.Request.do_next/1
    (ash 2.5.10) lib/ash/engine/request.ex:211: Ash.Engine.Request.next/1
    (ash 2.5.10) lib/ash/engine/engine.ex:650: Ash.Engine.advance_request/2
    (ash 2.5.10) lib/ash/engine/engine.ex:556: Ash.Engine.fully_advance_request/2
    (ash 2.5.10) lib/ash/engine/engine.ex:497: Ash.Engine.do_run_iteration/2
    iex:5: (file)

fummmp:

Thank you for the quick reply! It’s mostly complete but here’s the full module

defmodule Inventizr.Inventory.Item do
  use Ash.Resource,
    data_layer: AshPostgres.DataLayer,
    extensions: [AshAdmin.Resource]

  postgres do
    table "items"
    repo Inventizr.Repo
  end

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

    read :list do
      description "lists all the items"
      prepare build(sort: [inserted_at: :desc])
    end

    create :new do
      accept [:model, :brand]
    end
  end

  attributes do
    uuid_primary_key :id

    attribute :brand, :string
    attribute :model, :string

    attribute :status, :atom do
      constraints one_of: [:available, :in_use, :defect, :unavailable]
      default :available
      allow_nil? false
    end
  end

  relationships do
    belongs_to :user, Inventizr.Accounts.User do
      api Inventizr.Accounts
      attribute_writable? true
      allow_nil? true
    end
  end

  code_interface do
    define_for Inventizr.Inventory
    define :list, action: :read
    define :new
  end
end

ZachDaniel:

Should have a new version of ash_postgres in with a fix soon

ZachDaniel:

fix in v1.3.4

fummmp:

<@197905764424089601> you are amazing!

ZachDaniel:

😆 thanks for the kind words. Thanks for reporting the issue so we could fix it quickly.

ZachDaniel:

If your issue has been resolved, please add the Solved tag and close this thread by right clicking the thread in the sidebar and choosing Close Post.

fummmp:

I saw part 1 of the video yesterday and it finally made me try Ash. Excited for part 2! 🎉

ZachDaniel:

Well you’re in luck: https://discord.com/channels/711271361523351632/1068688488083492885

ZachDaniel:

🥳

fummmp:

Oh wow! You absolutely made my day now! ❤️

fummmp:

Will try tomorrow! Now I need some sleep..it’s 3AM here in Germany 🙈

ZachDaniel:

😆 go to bed

fummmp:

<@197905764424089601> you’re my hero! It works! Thank you again for the more than quick response and the effort to fix the bug immediately!

waseigo:

Hi <@245625838035271680>, quick question: in the belongs_to relationship, why do you add the line starting with api ? Also, does attribute_writable? true make the relationship capable of being defined by passing the relevant ..._id during the :create action?

waseigo:

On https://www.ash-hq.org/docs/guides/ash/latest/topics/relationships.md there is no such api line explained.

barnabasj:

You can have different API modules per e.g domain. If the related items are in configured in APIs you need to tell Ash which one to use.

ZachDaniel:

https://ash-hq.org/docs/dsl/ash/latest/resource/relationships/has_many

ZachDaniel:

in the DSL docs we explain each individual option

waseigo:

<@360450161845075968> aha, so if I only have one domain, then I don’t need it – but, e.g., if I wanted to make a relationship between the resource in my domain and a resource in ash_authentication’s accounts domain, then I use the api option?

waseigo:

got it, thanks!