ruby - Streaming data from Sinatra/Rack application

Question

I am trying to stream textual data (XML/JSON) from a Ruby (1.9.1p378) Sinatra (1.0) Rack (1.2.1) application. The suggested solutions (e.g. Is there a way to flush html to the wire in Sinatra) do not seem to work - the server just blocks when I yield elements of some infinite stream (e.g. from %w(foo bar).cycle). I tried webrick and thin as servers.

Any suggestions on getting this done? Should I use http://sinatra.rubyforge.org/api/classes/Sinatra/Streaming.html and if so how would I use it in my application?

Answer 1

Starting with Sinatra 1.3, you could also use the new streaming API:

get '/evented' do
  stream(:keep_open) do |out|
    EventMachine::PeriodicTimer.new(1) { out << "#{Time.now}
" }
  end
end