Class: Rack::JSONP

Inherits:
Object
  • Object
show all
Defined in:
lib/rack/contrib/jsonp.rb

Overview

A Rack middleware for providing JSON-P support.

Full credit to Flinn Mueller (actsasflinn.com/) for this contribution.

Instance Method Summary collapse

Constructor Details

#initialize(app) ⇒ JSONP

Returns a new instance of JSONP.



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# File 'lib/rack/contrib/jsonp.rb', line 9

def initialize(app)
  @app = app
end

Instance Method Details

#call(env) ⇒ Object

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 callback param is specified.



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# File 'lib/rack/contrib/jsonp.rb', line 18

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

#pad(callback, response, body = "") ⇒ Object

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.



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# File 'lib/rack/contrib/jsonp.rb', line 35

def pad(callback, response, body = "")
  response.each{ |s| body << s }
  "#{callback}(#{body})"
end