Support for asynchonous request handling

[ept]

Hi Calvin, thanks for rack-cors, loving it!

We're using asynchonous request processing in our app — you throw :async to tell the web server (e.g. thin) that the response will be sent later; then the web server can serve other requests, and once the response is ready, it is sent out via env['async.callback'].call([status, headers, body]).

I've extended rack-cors to support adding the CORS response headers to asynchonous responses as well. This is done by catching and re-throwing the throw :async, and by wrapping Rack's async callback in a proxy which adds the appropriate headers.

Feel free to use this change if you want :)

Martin

[sujal]

Hey folks, I've forked cyu's master branch and merged in this request. I then modified it to add support for Goliath (and any other server, I believe, that returns a status of -1 instead of throwing :async. My branch is here: https://github.com/sujal/rack-cors/tree/async_support.

Let me know what you think. I don't have a handy test case for the "throw" case, so if you could make sure I didn't break anything, that would help.

I do need think of a way to write a test for this. Not sure yet how to tackle that.

[funny-falcon]

Replacing env['async.callback'] should happen before calling original app inside of catch(:async){} cause application could save it to local variable before throwing :async

[karlfreeman]

Would love to see @sujal's fork make its way into rack-cors. :)

[quezacoatl]

Why will you not merge this?

[quezacoatl]

Actually it works to use async-rack instead:

require 'async-rack'

module AsyncRack
  class Cors < AsyncCallback(:Cors)
    include AsyncRack::AsyncCallback::SimpleWrapper
  end
end

[cyu]

I haven't had the opportunity to understand async handling in Rack works. I'll try to block off some time to look into this.

[demisx]

Any update on this please? Will this be merged?

[zabolotnov87]

:+1: