Resource Key in Form Setup for Nested Union Forms

Could you share the full code.

It seemes to me that you are using the form before passing it to to_form() function.

Union forms are pretty complex beasts TBH. There is typically no one resource that can be used to describe them, and the way that it is implemented when using auto?: true is that an updater function is provided, which will dynamically modify the resource/actions depending on the current parameters.

Is there any specific reason you’re building the form specification manually, as opposed to:

AshPhoenix.Form.for_create(
  ParentModule, 
  :create, 
  api: MyDomain.Api, 
  forms: [auto?: true]
)

I’m starting to see that too

Yeah, I tried auto?: true too. It returns ** (AshPhoenix.Form.NoFormConfigured) options at path [] must be configured in the form to be used with inputs_for

I’m not sure I understand what you mean

Does your action accept the options input? It is only generated for attributes that are accepted by the action.

The nested resource has an options attribute which is itself an embedded resource.

Since I’m still on 2.x, I believe actions accept all attributes by default. So, yes I guess.

For clarity, here’s a stripped-down copy of the resources involved:

defmodule ParentModule do
  attributes do
    attribute :children, {:array, ChildModule}
  end
end

defmodule ChildModule do
  use Ash.Type.NewType, subtype_of: :union, constraints: [types: [
    {ChildType1, [type: ChildType1, tag: :type, tag_value: "child_type_1"]},
  ]]
end

defmodule ChildType1 do
  attributes do
    attribute :options, {:array, Option}
  end
end

defmodule Option do
  attributes do
    attribute :value, :string
  end
end

For my setup:

socket = assign(socket, :form, AshPhoenix.Form.for_create(ParentModule, :create, api: MyApp.Api, forms: [auto?: true]))

And in my template:

    <.form :let={f} for={@form}>
      <.inputs_for :let={ff} field={f[:children]}>
        ...

        <.inputs_for :let={fff} field={ff[:options]}>
          ...
          <.input field={fff[:value]} placeholder="Option" />
        </.inputs_for>
      </.inputs_for>

      <.button action="action-that-triggers-error"> Click Me! </.button>
    </.form>

Does this help in identifying where my problem is coming from?

Ah, unfortunately a significant portion of the work that’s gone into properly supporting unions has been done in branches that depend on 3.0 and wouldn’t be back ported. Any chance you could upgrade in the near future?

Ouch. I was hoping to deliver this to production and then upgrade.

I guess I now have a business reason to get to that right away.

Thanks, Zach!

Ignore my response. I misunderstood your request.

Hey, Zach

I’ve upgraded to 3.0 and I still haven’t found a workaround using the response on Discord

Even with cast_tag?: true, on validation, I still get:

 %Ash.Error.Invalid.NoSuchInput{
  calculation: nil,
  resource: OneOfTheUnionTypes,
  action: :update,
  input: "type",
  inputs: MapSet.new([:id, :response, :prompt, "id", "prompt",
   "response"]),
  did_you_mean: [],
  splode: Ash.Error,
  bread_crumbs: [],
  vars: [],
  path: [],
  stacktrace: #Splode.Stacktrace<>,
  class: :invalid
}

The form is an update form, as per AshPhoenix.Form.for_update(resource, :action, domain: Domain, forms: [ auto?: true ])

I’ve been scouring through the Ash and AshPhoenix codebase to find what I’m doing wrong or what the cause might be. I’m still on that but nothing yet.

Any help is really appreciated.