Where `application/x-www-form-urlencoded` and `multipart/form-data`?

[AlexeyMatskevich]

I'm trying to contribute to the rspec-openapi library and I'm using hanami 2 in production. In rspec-openapi, there is a dummy test application on rails that I am trying to re-implementon hanami.

In particular, the original application in some cases transmits data in the following formats: application/x-www-form-urlencoded and multipart/form-data when upload images.

I'm reading this article https://guides.hanamirb.org/v2.1/actions/formats-and-mime-types/ and I'm following this link over 50 of the most common MIME types and I can't find the MIME-type I need in the list.

By default I'm using form :json, so I'm trying to get around the problem manually:

module HanamiTest

  class App < Hanami::App
    config.actions.formats.add(:form, "application/x-www-form-urlencoded")
    config.actions.formats.add(:multipart, "multipart/form-data")
    config.actions.format :json, :form, :multipart
  end
end

But I only succeed with form data.

I researched Hanami::Action::Mime.accepted_mime_type?

        def accepted_mime_type?(mime_type, config)
          accepted_mime_types(config).any? { |accepted_mime_type|
            ::Rack::Mime.match?(mime_type, accepted_mime_type)
          }
        end

i get

irb(Hanami::Action::Mime):001:0> mime_type
=> "multipart/form-data; boundary=----------XnJLe9ZIbbGUYtzPQJ16u1"
irb(Hanami::Action::Mime):002:0> accepted_mime_types(config)
=> ["multipart/form-data"]

I also found this code for FormParser but couldn't find any documentation for it and have no idea how to use it.

Any help would be appreciated.

[AlexeyMatskevich]

I found a workaround, remove format everywhere above inheritance and from app.rb
Action

module HanamiTest
  class Action < Hanami::Action
    format :json - remove
  end
end

App.rb

module HanamiTest
  class App < Hanami::App
    config.actions.format :json - remove
  end
end

[cllns]

@AlexeyMatskevich Thanks for reporting this issue. I've opened a PR adding :form and :multipart as built-in formats, which will be very helpful.

I think your "workaround" above is actually the solution to this problem. The config formats are the highest level and you were manually overriding them lower down the stack in your actions, so they weren't being respected. Does that sound correct?

[AlexeyMatskevich]

@cllns Yeah, that sounds about right! For me, this problem comes down to this example - “If I have a basic API application and I define format :json in the Action class - then I can't override the format in subclasses when I need to use multipart or form mimetype in one or two places, simply because that mimetype doesn't exist”.

[timriley]

This should now be fixed by #485.

As before, if your actions do not have any format configuration, then requests with Content-Typoe of "application/x-www-form-urlencoded" or "multipart/form-data" are accepted.

This is now also the case if your actions do have format config. So long as they accept the :html format, the above Content-Types will still be permitted.

So in your examples, this would be a matter of doing:

config.formats.accept :html, :json

The one missing piece is making sure you have the body parser enabled for "multipart/form-data" requests. I'm going to address this in a separate PR, and will close this issue after that is done :)

[timriley]

And here's the PR where we parse multipart/form-data bodies by default, no user config required: hanami/hanami#1549

Once this merges, I think we can consider this issue resolved.

[timriley]

This is all merged now :) It will be released with Hanami 2.3 shortly.