Contents

module G5K
  module Rack
  
    # A Rack middleware for providing JSON-P support.
    # 
    # Full credit to Flinn Mueller (http://actsasflinn.com/) for this contribution.
    # 
    class JSONP
    
      def initialize(app)
        @app = app
      end
    
      # Proxies the request to the application, stripping out the JSON-P callback
      # method and padding the response with the appropriate callback format.
      # 
      # Changes nothing if no <tt>callback</tt> param is specified.
      # 
      def call(env)
        status, headers, response = @app.call(env)
        request = Rack::Request.new(env)
        if request.params.include?('callback')
          response = pad(request.params.delete('callback'), response)
          headers['Content-Length'] = response.length.to_s
        end
        [status, headers, response]
      end
    
      # Pads the response with the appropriate callback format according to the
      # JSON-P spec/requirements.
      # 
      # The Rack response spec indicates that it should be enumerable. The method
      # of combining all of the data into a single string makes sense since JSON
      # is returned as a full string.
      # 
      def pad(callback, response, body = "")
        response.each{ |s| body << s }
        "#{callback}(#{body})"
      end
    
    end
  end
end

Version data entries

2 entries across 2 versions & 1 rubygems

Version	Path
cryx-g5k-0.1.0	lib/g5k/rack/jsonp.rb
cryx-g5k-0.2.0	lib/g5k/rack/jsonp.rb