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Merge pull request #11443 from wangjohn/sse_reloader_class

SSE class for ActionController::Live
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2 parents a0b948e + d2d6aef commit f97fdace5446cc17ec49392b57c2f34d489f0167 @spastorino spastorino committed Aug 19, 2013
Showing with 162 additions and 0 deletions.
  1. +74 −0 actionpack/lib/action_controller/metal/live.rb
  2. +88 −0 actionpack/test/controller/live_stream_test.rb
@@ -1,5 +1,6 @@
require 'action_dispatch/http/response'
require 'delegate'
+require 'active_support/json'
module ActionController
# Mix this module in to your controller, and all actions in that controller
@@ -32,6 +33,79 @@ module ActionController
# the main thread. Make sure your actions are thread safe, and this shouldn't
# be a problem (don't share state across threads, etc).
module Live
+ # This class provides the ability to write an SSE (Server Sent Event)
+ # to an IO stream. The class is initialized with a stream and can be used
+ # to either write a JSON string or an object which can be converted to JSON.
+ #
+ # Writing an object will convert it into standard SSE format with whatever
+ # options you have configured. You may choose to set the following options:
+ #
+ # 1) Event. If specified, an event with this name will be dispatched on
+ # the browser.
+ # 2) Retry. The reconnection time in milliseconds used when attempting
+ # to send the event.
+ # 3) Id. If the connection dies while sending an SSE to the browser, then
+ # the server will receive a +Last-Event-ID+ header with value equal to +id+.
+ #
+ # After setting an option in the constructor of the SSE object, all future
+ # SSEs sent accross the stream will use those options unless overridden.
+ #
+ # Example Usage:
+ #
+ # class MyController < ActionController::Base
+ # include ActionController::Live
+ #
+ # def index
+ # response.headers['Content-Type'] = 'text/event-stream'
+ # sse = SSE.new(response.stream, retry: 300, event: "event-name")
+ # sse.write({ name: 'John'})
+ # sse.write({ name: 'John'}, id: 10)
+ # sse.write({ name: 'John'}, id: 10, event: "other-event")
+ # sse.write({ name: 'John'}, id: 10, event: "other-event", retry: 500)
+ # ensure
+ # sse.close
+ # end
+ # end
+ #
+ # Note: SSEs are not currently supported by IE. However, they are supported
+ # by Chrome, Firefox, Opera, and Safari.
+ class SSE
+
+ WHITELISTED_OPTIONS = %w( retry event id )
+
+ def initialize(stream, options = {})
+ @stream = stream
+ @options = options
+ end
+
+ def close
+ @stream.close
+ end
+
+ def write(object, options = {})
+ case object
+ when String
+ perform_write(object, options)
+ else
+ perform_write(ActiveSupport::JSON.encode(object), options)
+ end
+ end
+
+ private
+
+ def perform_write(json, options)
+ current_options = @options.merge(options).stringify_keys
+
+ WHITELISTED_OPTIONS.each do |option_name|
+ if (option_value = current_options[option_name])
+ @stream.write "#{option_name}: #{option_value}\n"
+ end
+ end
+
+ @stream.write "data: #{json}\n\n"
+ end
+ end
+
class Buffer < ActionDispatch::Response::Buffer #:nodoc:
def initialize(response)
@error_callback = nil
@@ -2,6 +2,94 @@
require 'active_support/concurrency/latch'
module ActionController
+ class SSETest < ActionController::TestCase
+ class SSETestController < ActionController::Base
+ include ActionController::Live
+
+ def basic_sse
+ response.headers['Content-Type'] = 'text/event-stream'
+ sse = SSE.new(response.stream)
+ sse.write("{\"name\":\"John\"}")
+ sse.write({ name: "Ryan" })
+ ensure
+ sse.close
+ end
+
+ def sse_with_event
+ sse = SSE.new(response.stream, event: "send-name")
+ sse.write("{\"name\":\"John\"}")
+ sse.write({ name: "Ryan" })
+ ensure
+ sse.close
+ end
+
+ def sse_with_retry
+ sse = SSE.new(response.stream, retry: 1000)
+ sse.write("{\"name\":\"John\"}")
+ sse.write({ name: "Ryan" }, retry: 1500)
+ ensure
+ sse.close
+ end
+
+ def sse_with_id
+ sse = SSE.new(response.stream)
+ sse.write("{\"name\":\"John\"}", id: 1)
+ sse.write({ name: "Ryan" }, id: 2)
+ ensure
+ sse.close
+ end
+ end
+
+ tests SSETestController
+
+ def wait_for_response_stream_close
+ while !response.stream.closed?
+ sleep 0.01
+ end
+ end
+
+ def test_basic_sse
+ get :basic_sse
+
+ wait_for_response_stream_close
+ assert_match(/data: {\"name\":\"John\"}/, response.body)
+ assert_match(/data: {\"name\":\"Ryan\"}/, response.body)
+ end
+
+ def test_sse_with_event_name
+ get :sse_with_event
+
+ wait_for_response_stream_close
+ assert_match(/data: {\"name\":\"John\"}/, response.body)
+ assert_match(/data: {\"name\":\"Ryan\"}/, response.body)
+ assert_match(/event: send-name/, response.body)
+ end
+
+ def test_sse_with_retry
+ get :sse_with_retry
+
+ wait_for_response_stream_close
+ first_response, second_response = response.body.split("\n\n")
+ assert_match(/data: {\"name\":\"John\"}/, first_response)
+ assert_match(/retry: 1000/, first_response)
+
+ assert_match(/data: {\"name\":\"Ryan\"}/, second_response)
+ assert_match(/retry: 1500/, second_response)
+ end
+
+ def test_sse_with_id
+ get :sse_with_id
+
+ wait_for_response_stream_close
+ first_response, second_response = response.body.split("\n\n")
+ assert_match(/data: {\"name\":\"John\"}/, first_response)
+ assert_match(/id: 1/, first_response)
+
+ assert_match(/data: {\"name\":\"Ryan\"}/, second_response)
+ assert_match(/id: 2/, second_response)
+ end
+ end
+
class LiveStreamTest < ActionController::TestCase
class TestController < ActionController::Base
include ActionController::Live

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