How to manage `belongs_to` relations

I have this action in my resource

    create :new_token do
      accept([:nickname, :scopes, :system, :expires_at])

      argument :user, Project.Resources.Accounts.User do
        allow_nil?(false)
      end

      change(manage_relationship(:user, on_match: :relate))

      # ...
  end

    create :new_token do
      accept([:nickname, :scopes, :system, :expires_at])

      argument :user, Project.Resources.Accounts.User do
        allow_nil?(false)
      end

      change(manage_relationship(:user, on_match: :relate))

      # ...
  end

but when I create a new token, the user and user_id are nil

           |> Ash.Changeset.for_create(:new_token, %{
             user: user,
             system: true,
             scopes: ["read", "write"],
             expires_at:
               DateTime.utc_now()
               |> DateTime.add(@max_age, :second)
               |> DateTime.truncate(:second)
           })

           |> Ash.Changeset.for_create(:new_token, %{
             user: user,
             system: true,
             scopes: ["read", "write"],
             expires_at:
               DateTime.utc_now()
               |> DateTime.add(@max_age, :second)
               |> DateTime.truncate(:second)
           })

7 Replies

ZachDaniel•3y ago

Ah, so I think the issue is the on_match option. I believe you want on_lookup: :relate Alternatively, you can use type: :append_and_remove That is the generalized type for "add the new thing, remove the old thing if it exists" without creating or deleting anything (only changing what is related)

harryOP•3y ago

Thanks that fixed it 🙌🏼 nearly finished moving everything over to Ash so I can do one mamoth commit today ~60 files changed

ZachDaniel•3y ago

Thats awesome 😄 Is your project open source?

harryOP•3y ago

Sadly not 😞

ZachDaniel•3y ago

No problem at all, just curious 😄 If you could write a few words on your migration experience that would be really cool. Perhaps posting something in #showcase .

harryOP•3y ago

Yeah I'm planning a personal blog post; no company engineering blog yet 🤣

ZachDaniel•3y ago

excellent! Looking forward to it.

Gaming

Programming

How to manage `belongs_to` relations

Did you find this page helpful?