File upload with SPQR Graphql

Question

I'm using spring boot and spqr graphql library. I need to upload a file(s) via graphql. I don't know what object type to expect in the service and I'm assuming that this isn't even supported.

Has anyone tried this? Any advice?

Thanks.

Answer 1

(Assuming you're using SPQR Spring Starter) Uploading/downloading binaries is currently inconvenient in SPQR, but not impossible. You'd need to override the provided controller with your own and decide how you want to receive the queries and binaries, and how you want to send the results and binaries back. To override the controller, just provide your own bean of GraphQLController type.

Your best bet is implementing the GraphQL multipart request spec which thanks to Spring shouldn't be too complicated.

Btw you can always get to the raw request by injecting @GraphQLRootContext DefaultGlobalContext<NativeWebRequest> request as a method argument. From there you can obtain input and output streams.

You can also wire in a custom ArgumentInjector that can inject something more precise if you want.

In the near future, the starter will support the GraphQL multipart request spec out of the box.

If you're not using the starter, the situation is similar in that you're kind of on your own with implementing the transport for binaries and queries.

But, with all that said, it is generally a best practice to handle dealing with binaries outside of GraphQL completely (only send download URLs and such using GraphQL), so I highly recommend that approach if possible. The reason is that requiring optional specs breaks out-of-the-box compatibility with most clients.