Enable returning 204 No Content

[p-originate]

Per the readme, a formatter must supply a content type. However, when sending an empty response body, no content type is wanted at all.

Related issue is #215. As far as I see even with my own formatter I cannot return empty response bodies/204 no content.

[dblock]

I've renamed this to "Enable returning 204 No Content".

See #618 for a possible solution, still looking forward to a PR.

[p-originate]

I do not want to serve a text/plain response to a request that expects a json response (http://.../foo.json).

An empty string, not being valid json, also won't work.

[p-originate]

I don't know if I will be the person sending requested PR, but, do you care what the api for this functionality looks like?

[dblock]

So, if you want to return valid JSON, you should return {}, but a 204 No Content (or similar) is definitely a valid response too.

I really don't have a strong opinion of what the API looks like, but I can comment when I see a suggestion :)

[dblock]

I chose body false to return a 204 No Content, which is just an alias for:

@body = nil
status 204

#850

[stephancom]

I realize this is closed, but I wanted to share an issue I just ran into the hard way.
Apparently, @body = nil will cause errors if you're using Rack::Lint.

ERROR -- : app error: Body yielded non-string value 204 (Rack::Lint::LintError)

Reason being that, it would seem, the Rack spec does not precisely follow HTTP spec. There is some dissent on the matter, as seen in a related issue (no content-type for empty body) here:
rack/rack#472

But the spec states:

The Body must respond to each and must only yield String values. The Body itself should not be an instance of String, as this will break in Ruby 1.9.

https://github.com/rack/rack/blob/master/SPEC#L244-L248

This just came up, I'll be solving it tomorrow, I suspect @body = [] or @body = {} should fix it, as appropriate.

I hope this helps someone else.

edit: here's a related StackOverflow discussion:
https://stackoverflow.com/questions/7701113/rack-error-racklintlinterror-response-body-must-respond-to-each

[dblock]

My question in rack#472 remained unanswered btw.

[stephancom]

@dblock oh, haha, I hadn't even noticed that was you. Now I'm not sure if I'm right about this, turns out I had a bigger issue going on - has this been your experience, do I need to return [] or is nil actually OK?

[dblock]

I guess the answer is "I am not sure"...