File upload mutation with Abinthe giving "no query document supplied" error

Harrygr

I’m trying to build an upload component to allow uploading of files over graphql. I’m using Absinthe for the server aspect and React + URQL (along with the multipart fetch exchange) for the frontend. I’ve followed the file uploads section of the Absinthe docs and I have it working via curl as follows:

curl -v -X POST -F query="mutation { uploadFile(input: {file: \"myfile\"}) { result }}" -F myfile=@avatar.png localhost:4000/graphql

However I can’t seem to get this same mutation to work when using URQL. The server just responds with a “no query document supplied” error.

Here’s an example of the multipart request from the browser:

-----------------------------283482549016739198714264561499
Content-Disposition: form-data; name="operations"

{"variables":{"input":{"file":null}},"query":"mutation UploadFile($input: UploadFileInput!) {\n  uploadFile(input: $input) {\n    result\n    __typename\n  }\n}\n"}
-----------------------------283482549016739198714264561499
Content-Disposition: form-data; name="map"

{"1":["variables.input.file"]}
-----------------------------283482549016739198714264561499
Content-Disposition: form-data; name="1"; filename="avatar.png"
Content-Type: image/png

PNG
 <rest of image data

Could there be a discrepency between implementations?

6 comments

/phoenix #graphql #absinthe

0 4383 6

2024-05-22 21:27:19 UTC

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benwilson512

Author of Craft GraphQL APIs in Elixir with Absinthe

Yes, URQL is using a different pattern for file uploads. I’ve been fighting this spec forever because I hate the use of null as a marker for a value that is not null. However it seems this spec is getting popular and this is a fight I’m going to lose eventually. sigh.

Post #1

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sb8244

Author of Real-Time Phoenix

I found this thread when googling. I didn’t want to rewrite anything on the client because that sounds pretty rough, so I went for the Elixir rewriting approach. I hooked into multipart_to_params, an option to the Plug.Parsers plug that’s usually put in Endpoint

This code works for my simple case locally. I didn’t test with multiple files because that’s not a use case for me. I also didn’t worry about graceful params handling. Use at own risk, but possibly a decent starting point:

defmodule RewriteMultipart do
  def multipart_params(parts, conn) do
    params =
      for {name, _headers, body} <- parts,
          name != nil,
          reduce: %{} do
        acc -> Plug.Conn.Query.decode_pair({name, body}, acc)
      end

    params = case params do
      %{"operations" => operations, "map" => map} ->
        map = Jason.decode!(map)
        operations = Jason.decode!(operations)

        # Transform the file map to the query variables
        vars =
          Enum.reduce(map, operations["variables"], fn mapping, vars ->
            {name, [path]} = mapping
            path = String.split(path, ".") -- ["variables"]
            put_in(vars, path, name)
          end)

        # New query drops operations/map in favor of query/variables
        params
        |> Map.drop(["operations", "map"])
        |> Map.merge(%{"variables" => vars, "query" => operations["query"]})

      _ ->
        params
    end

    {:ok, params, conn}
  end
end

Post #5

sescobb27

for posterity, i adapted some solutions into this with some basic tests and a way to do an integration test absinthe integration with apollo's file upload · GitHub

Post #6