How to use arguments on nested items in my query using Absinthe in Elixir?

Question

I'm trying to find out how to use arguments on nested items in my query using Absinthe.

What I try to accomplish is this:

{
  users(order: ASC) {
    id
    email
    clients(order: DESC) {
      id
      email
    }
  }
}

Here's my Schema and Type:

  query do
    @desc "Get all users"
    field :users, list_of(:user) do
      arg :order, type: :sort_order, default_value: :asc
      resolve &Resolvers.users/2
    end
  end

  @desc "A user"
  object :user do
    field :id, :id
    field :email, :string
    field :clients, list_of(:user)
  end

And the resolver:

  def users(_, args, _) do
    args
    |> Enum.reduce(User, fn
      {:order, order}, query ->
        query |> order_by({^order, :email})
    end)
    |> Repo.all |> Repo.preload([:clients])
  end

So my question is how and where should I place the sorting argument for the clients? With the above example I get an error:

"message": "Unknown argument \"order\" on field \"clients\" of type \"User\"."

This [Q & A](https://stackoverflow.com/questions/34155439/getting-error-unknown-argument-id-on-field-user-of-type-query-graphql?rq=1) might have something to help you. — Onorio Catenacci, Oct 10 '17 at 14:45

score 5 · Accepted Answer · answered Jan 18 '18 at 19:53

Put the argument under the clients field:

object :user do
  field :id, :id
  field :email, :string
  field :clients, list_of(:user) do
    arg :order, type: :sort_order, default_value: :asc
    resolve &Resolvers.clients/2
  end
end

Then write a resolver to handle the sorting:

def clients(user, %{order: clients_order}, _) do
  sorted_clients = user.clients # TODO sort those clients into the desired order
  {:ok, sorted_clients}
end

How to use arguments on nested items in my query using Absinthe in Elixir?

1 Answers1