Billzabob
Using Absinthe Dataloader for top level queries
I’m trying to figure out how to use Dataloader with absinthe for a top level query. I have it working just fine for a field on an object, like so:
defmodule UserSchema do
use Absinthe.Schema.Notation
import Absinthe.Resolution.Helpers, only: [dataloader: 1]
alias Core.Loaders.CardLoader
object :user do
field(:cards, list_of(:card), resolve: dataloader(CardLoader))
end
end
However, I’d like to also be able to use Dataloader for top level queries like so:
query do
field(:cards, list_of(:card), resolve: dataloader(CardLoader))
end
But this fails with this error:
** (Dataloader.GetError) The given atom - :cards - is not a module.
This can happen if you intend to pass an Ecto struct in your call to
`dataloader/4` but pass something other than a struct.
How can I achieve this? I could obviously do it another way, by having the resolver function call Repo.all(Card) but I’d love to be able to do it all with Dataloader. Is that possible?
First Post!
VictorGaiva
Usually you need explicit resolvers since most the time a query will receive parameters, from args or from the current logged user, so that you can specify how to fetch the data you want.
Most Liked
Billzabob
I ended up getting this working with the following:
import Absinthe.Resolution.Helpers, only: [on_load: 2]
query do
field :users, list_of(:user) do
arg(:ids, non_null(list_of(:id)))
resolve(fn %{ids: ids}, %{context: %{loader: loader}} ->
loader
|> Dataloader.load_many(UserLoader, User, ids)
|> on_load(fn loader ->
users = Dataloader.get_many(loader, UserLoader, User, ids)
{:ok, users}
end)
end)
end
end
Popular in Questions
Other popular topics
Latest on Elixir Forum
Sponsor Spotlight
Practical resources that improve the lives of professional developers.
Categories:
Sub Categories:
Forums
Popular Tags
- #ecto
- #liveview
- #troubleshooting
- #learning-elixir
- #deployment
- #library
- #erlang
- #testing
- #genserver
- #mix
- #absinthe
- #remote-other
- #otp
- #plug
- #how-to-question
- #macros
- #postgres
- #channels
- #elixirconf
- #exunit
- #discussion
- #code-sync
- #javascript
- #podcasts
- #onsite
- #dialyzer
- #docker
- #authentication
- #umbrella
- #full-time-contract
- #podcasts-by-brainlid
- #ecto-query
- #elixir-ls
- #phoenix_html
- #iex
- #blog-post
- #graphql
- #genstage
- #ai
- #websockets
- #supervisor
- #elixirconf-us
- #advent-of-code
- #distillery
- #processes
- #api
- #forms
- #metaprogramming
- #security
- #hex
Our Sponsors
Build Elixir applications with speed and confidence.
Supporting innovation across the BEAM ecosystem.
We build reliable cloud platforms for business-critical systems.
Catch errors, track performance, monitor hosts and more.
Error tracking, logs, uptime, and Just Enough APM. Built for developers.
Practical resources that improve the lives of professional developers.
Develop your skills with books, videos, and courses.
The deployment platform built for Elixir: PaaS ease, VPS control.
The team behind Membrane, Popcorn, LiveDebugger. Available for hire.
Courses that'll move you from confusion to "Aha, now I get it!"