Nested form data

[adriangb]

In multipart/form-data requests each field has it's own content-type.
So (I think) you can have nested multipart/form-data fields, or at least multipart/form-data -> multipart x-www-form-urlencoded.
Does the spec support this sort of request body?

Thanks!

[handrews]

The Content-Type header has to go in the contentType field of the Encoding Object. But I don't see any way you can easily describe that situation as there's nowhere to put a nested Media Type Object. In OAS 3.1 you could maybe do something very complicated with the JSON Schema contentMediaType keyword, but the chances of finding any tooling support is slim. It feels like too niche of a use case to justify the complexity that would be involved in adding recursive nesting.

Since this feels like a simple yes/no answer and it's several years old, I'm going to close this, but feel free to comment if I have missed something and I can re-open it. If you want to request this as a feature, you probably want to do so in the OAS 4 "Moonwalk" discussions as it it too big of a change for a minor release. But it does feel too complex for the benfit to me (my personal opinion only, not the opinion of the project!)

[handrews]

See also #3721 where this has also come up - idk if it will fit in 3.2 or Moonwalk, but if it can go in 3.2 it will be tracked on that issue.