Feature: support standard GQL upload requests

[timmywil]

Absinthe currently expects something like:

curl localhost:4000/graphql
  -F query="mutation { uploadFile(users: \"users_csv\") }" \
  -F users_csv=@users.csv

But, the graphql multipart request spec, used not only by Apollo but all other GQL servers these days, instead defines the following format:

curl localhost:4000/graphql \
  -F operations='{ "query": "mutation ($file: Upload!) { singleUpload(file: $file) { id } }", "variables": { "file": null } }' \
  -F map='{ "0": ["variables.file"] }' \
  -F 0=@a.txt

While the latter may seem longer, it's actually simpler as the operation can be parsed in much the same way as normal GQL mutations. It's also worth noting additional variables are handled very differently.

While the Absinthe docs for File Uploads does provide a solution for Apollo by linking to apollo-absinthe-upload-link, that code has not been touched in 5 years and no longer works reliably.

In comparison, the spec linked above has time-tested and maintained implementations not only for Apollo, but several other clients and servers. I am currently building a Flutter app, for which there is no Absinthe-compatible solution and I'll likely end up having to write my own GQL link.

This issue is simply a feature request to support the format that everyone else is using for uploads. You would not only be able to recommend Absinthe to those not using Apollo, you would no longer need to recommend an unmaintained, custom apollo link. The existing GQL links would just work.

Thanks for your time.

[benwilson512]

Hey @timmywil as far as I can tell there is no blocker to someone writing a plug which supports this right?

[timmywil]

Yes, I think maybe I should have put this on https://github.com/absinthe-graphql/absinthe_plug. There's this, but it also hasn't been touched in 5 years. And yet, the strategy there is that it just rewrites the request to what absinthe_plug expects. My proposal would change what absinthe_plug expects so that no other plug is required. It is certainly a breaking change, but should be a future-proof one.

I could be wrong, but an admin may be able to transfer this issue to the plug repo. Thanks.

[maxsalven]

I found this useful:

https://gist.github.com/sescobb27/8e42d39a78bddb0a728d260a0f2c29f6