Switch to drf-spectacular as OAS scheme generator

[n2ygk]

Per encode/django-rest-framework#8453 upstream DRF is deprecating the internal schema generator in lieu of recommending use of drf-spectactular so we'll need to do the same since our openapi schema support extends DRF's and there have been outstanding upstream improvements (such as encode/django-rest-framework#7516) that will never be implemented in DRF.

[sliverc]

Thanks for bringing up this discussion.

So far schema generator has not been deprecated in DRF. Once it is, we should also follow and deprecate it in DJA. Till then, I am happy to integrate small improvements like doc updates or obvious errors etc.

As OpenAPI won't be a direct feature of DRF anymore and also not a requirement of the JSON:API spec I would love to see a separate library based on drf-spectacular to be developed like drf-spectacular-json-api. This would follow the spirit of DRF and drf-yasg-json-api is a great example where this worked out well.

Would be anyone willing working on such a library?

[sliverc]

@n2ygk
As issue jokiefer/drf-spectacular-json-api#20 has now been solved, do you think drf-spectecular-json-api is now on par with DJA?

If so, I would suggest we officially deprecate OAS in DJA as DRF did.

Three things I see we should do:

1. add a deprecation notice to the schema docs in the lines like DRF
2. add a deprecation warning when running the DJA schema command
3. add drf-spectecular-json-api to the list of our 3rdParty libraries.

What do you think?

[axieum]

This is great to see.

I support the above points, with the addition to fix the spelling in the repository name.

This rename shouldn't impact functionality as the package appears to have been published with the correct spelling.

[n2ygk]

I need to finish integrating it in my demo app to be sure, but it seems like it is better than the existing DRF schema stuff.

[sliverc]

@n2ygk Good. Let us know once you have it fully integrated and whether you find any other not covered edge cases.

@axieum True, the naming is indeed not consistent. Best report it in the upstream repository so it can be fixed.

[n2ygk]

@sliverc I think we are good to go with deprecating the old DRF schema stuff. I've got it working with my demo app and, after making a few teaks and documentation updates, I'll merge those changes.

@jokiefer has done a great job with drf-spectacular-json-api!