Added protocol negotiation

This is primarily for backwards compatibility for when
or if the protocol is changed in future versions.

If the server fails to respond with an acceptable
protocol, the client disconnects and disables
the monitor.

8 files changed, 73 insertions, 24 deletions

diff --git a/actioncable/app/assets/javascripts/action_cable/connection.coffee b/actioncable/app/assets/javascripts/action_cable/connection.coffee
index 92272cc5b8..af771f2d82 100644
--- a/actioncable/app/assets/javascripts/action_cable/connection.coffee
+++ b/actioncable/app/assets/javascripts/action_cable/connection.coffee
@@ -2,7 +2,8 @@
 
 # Encapsulate the cable connection held by the consumer. This is an internal class not intended for direct user manipulation.
 
-{message_types} = ActionCable.INTERNAL
+{message_types, protocols} = ActionCable.INTERNAL
+[supportedProtocols..., unsupportedProtocol] = protocols
 
 class ActionCable.Connection
   @reopenDelay: 500
@@ -10,6 +11,7 @@ class ActionCable.Connection
   constructor: (@consumer) ->
     {@subscriptions} = @consumer
     @monitor = new ActionCable.ConnectionMonitor this
+    @disconnected = true
 
   send: (data) ->
     if @isOpen()
@@ -23,15 +25,16 @@ class ActionCable.Connection
       ActionCable.log("Attemped to open WebSocket, but existing socket is #{@getState()}")
       throw new Error("Existing connection must be closed before opening")
     else
-      ActionCable.log("Opening WebSocket, current state is #{@getState()}")
+      ActionCable.log("Opening WebSocket, current state is #{@getState()}, subprotocols: #{protocols}")
       @uninstallEventHandlers() if @webSocket?
-      @webSocket = new WebSocket(@consumer.url)
+      @webSocket = new WebSocket(@consumer.url, protocols)
       @installEventHandlers()
       @monitor.start()
       true
 
-  close: ->
-    @webSocket?.close()
+  close: ({allowReconnect} = {allowReconnect: true}) ->
+    @monitor.stop() unless allowReconnect
+    @webSocket?.close() if @isActive()
 
   reopen: ->
     ActionCable.log("Reopening WebSocket, current state is #{@getState()}")
@@ -46,6 +49,9 @@ class ActionCable.Connection
     else
       @open()
 
+  getProtocol: ->
+    @webSocket?.protocol
+
   isOpen: ->
     @isState("open")
 
@@ -54,6 +60,9 @@ class ActionCable.Connection
 
   # Private
 
+  isProtocolSupported: ->
+    @getProtocol() in supportedProtocols
+
   isState: (states...) ->
     @getState() in states
 
@@ -74,10 +83,12 @@ class ActionCable.Connection
 
   events:
     message: (event) ->
+      return unless @isSupportedProtocol()
       {identifier, message, type} = JSON.parse(event.data)
       switch type
         when message_types.welcome
           @monitor.recordConnect()
+          @subscriptions.reload()
         when message_types.ping
           @monitor.recordPing()
         when message_types.confirmation
@@ -88,20 +99,18 @@ class ActionCable.Connection
           @subscriptions.notify(identifier, "received", message)
 
     open: ->
-      ActionCable.log("WebSocket onopen event")
+      ActionCable.log("WebSocket onopen event, using '#{@getProtocol()}' subprotocol")
       @disconnected = false
-      @subscriptions.reload()
+      if not @isProtocolSupported()
+        ActionCable.log("Protocol is unsupported. Stopping monitor and disconnecting.")
+        @close(allowReconnect: false)
 
-    close: ->
+    close: (event) ->
       ActionCable.log("WebSocket onclose event")
-      @disconnect()
+      return if @disconnected
+      @disconnected = true
+      @monitor.recordDisconnect()
+      @subscriptions.notifyAll("disconnected", {willAttemptReconnect: @monitor.isRunning()})
 
     error: ->
       ActionCable.log("WebSocket onerror event")
-      @disconnect()
-
-  disconnect: ->
-    return if @disconnected
-    @disconnected = true
-    @subscriptions.notifyAll("disconnected")
-    @monitor.recordDisconnect()
diff --git a/actioncable/app/assets/javascripts/action_cable/consumer.coffee b/actioncable/app/assets/javascripts/action_cable/consumer.coffee
index 7aae1ed8ed..3298be717f 100644
--- a/actioncable/app/assets/javascripts/action_cable/consumer.coffee
+++ b/actioncable/app/assets/javascripts/action_cable/consumer.coffee
@@ -14,6 +14,19 @@
 #   App.appearance = App.cable.subscriptions.create "AppearanceChannel"
 #
 # For more details on how you'd configure an actual channel subscription, see ActionCable.Subscription.
+#
+# When a consumer is created, it automatically connects with the server.
+#
+# To disconnect from the server, call
+#
+#   App.cable.disconnect()
+#
+# and to restart the connection:
+#
+#   App.cable.connect()
+#
+# Any channel subscriptions which existed prior to disconnecting will
+# automatically resubscribe.
 class ActionCable.Consumer
   constructor: (@url) ->
     @subscriptions = new ActionCable.Subscriptions this
@@ -22,6 +35,12 @@ class ActionCable.Consumer
   send: (data) ->
     @connection.send(data)
 
+  connect: ->
+    @connection.open()
+
+  disconnect: ->
+    @connection.close(allowReconnect: false)
+
   ensureActiveConnection: ->
     unless @connection.isActive()
       @connection.open()
diff --git a/actioncable/app/assets/javascripts/action_cable/subscription.coffee b/actioncable/app/assets/javascripts/action_cable/subscription.coffee
index 61a3fb1309..8e0805a174 100644
--- a/actioncable/app/assets/javascripts/action_cable/subscription.coffee
+++ b/actioncable/app/assets/javascripts/action_cable/subscription.coffee
@@ -8,6 +8,12 @@
 #     connected: ->
 #       # Called once the subscription has been successfully completed
 #
+#     disconnected: ({ willAttemptReconnect: boolean }) ->
+#       # Called when the client has disconnected with the server.
+#       # The object will have an `willAttemptReconnect` property which
+#       # says whether the client has the intention of attempting
+#       # to reconnect.
+#
 #     appear: ->
 #       @perform 'appear', appearing_on: @appearingOn()
 #
diff --git a/actioncable/lib/action_cable.rb b/actioncable/lib/action_cable.rb
index 68a5fff3e7..b6d2842867 100644
--- a/actioncable/lib/action_cable.rb
+++ b/actioncable/lib/action_cable.rb
@@ -35,7 +35,8 @@ module ActionCable
       confirmation: 'confirm_subscription'.freeze,
       rejection: 'reject_subscription'.freeze
     },
-    default_mount_path: '/cable'.freeze
+    default_mount_path: '/cable'.freeze,
+    protocols: ["actioncable-v1-json".freeze, "actioncable-unsupported".freeze].freeze
   }
 
   # Singleton instance of the server
diff --git a/actioncable/lib/action_cable/connection/base.rb b/actioncable/lib/action_cable/connection/base.rb
index b4488265cb..43c83b4b78 100644
--- a/actioncable/lib/action_cable/connection/base.rb
+++ b/actioncable/lib/action_cable/connection/base.rb
@@ -48,7 +48,7 @@ module ActionCable
       include InternalChannel
       include Authorization
 
-      attr_reader :server, :env, :subscriptions, :logger, :worker_pool
+      attr_reader :server, :env, :subscriptions, :logger, :worker_pool, :protocol
       delegate :event_loop, :pubsub, to: :server
 
       def initialize(server, env)
@@ -153,6 +153,7 @@ module ActionCable
 
       private
         def handle_open
+          @protocol = websocket.protocol
           connect if respond_to?(:connect)
           subscribe_to_internal_channel
           send_welcome_message
diff --git a/actioncable/lib/action_cable/connection/client_socket.rb b/actioncable/lib/action_cable/connection/client_socket.rb
index 9e4dbcd6e6..cf529ebd81 100644
--- a/actioncable/lib/action_cable/connection/client_socket.rb
+++ b/actioncable/lib/action_cable/connection/client_socket.rb
@@ -29,7 +29,7 @@ module ActionCable
 
       attr_reader :env, :url
 
-      def initialize(env, event_target, event_loop)
+      def initialize(env, event_target, event_loop, protocols)
         @env          = env
         @event_target = event_target
         @event_loop   = event_loop
@@ -42,7 +42,7 @@ module ActionCable
         @ready_state = CONNECTING
 
         # The driver calls +env+, +url+, and +write+
-        @driver = ::WebSocket::Driver.rack(self)
+        @driver = ::WebSocket::Driver.rack(self, protocols: protocols)
 
         @driver.on(:open)    { |e| open }
         @driver.on(:message) { |e| receive_message(e.data) }
@@ -109,6 +109,10 @@ module ActionCable
         @ready_state == OPEN
       end
 
+      def protocol
+        @driver.protocol
+      end
+
       private
         def open
           return unless @ready_state == CONNECTING
diff --git a/actioncable/lib/action_cable/connection/faye_client_socket.rb b/actioncable/lib/action_cable/connection/faye_client_socket.rb
index c9139b6858..09834ca39d 100644
--- a/actioncable/lib/action_cable/connection/faye_client_socket.rb
+++ b/actioncable/lib/action_cable/connection/faye_client_socket.rb
@@ -3,9 +3,10 @@ require 'faye/websocket'
 module ActionCable
   module Connection
     class FayeClientSocket
-      def initialize(env, event_target, stream_event_loop)
+      def initialize(env, event_target, stream_event_loop, protocols)
         @env = env
         @event_target = event_target
+        @protocols = protocols
 
         @faye = nil
       end
@@ -23,6 +24,10 @@ module ActionCable
         @faye && @faye.close
       end
 
+      def protocol
+        @faye && @faye.protocol
+      end
+
       def rack_response
         connect
         @faye.rack_response
@@ -31,7 +36,7 @@ module ActionCable
       private
         def connect
           return if @faye
-          @faye = Faye::WebSocket.new(@env)
+          @faye = Faye::WebSocket.new(@env, @protocols)
 
           @faye.on(:open)    { |event| @event_target.on_open }
           @faye.on(:message) { |event| @event_target.on_message(event.data) }
diff --git a/actioncable/lib/action_cable/connection/web_socket.rb b/actioncable/lib/action_cable/connection/web_socket.rb
index 0bec9b6a96..11f28c37e8 100644
--- a/actioncable/lib/action_cable/connection/web_socket.rb
+++ b/actioncable/lib/action_cable/connection/web_socket.rb
@@ -4,8 +4,8 @@ module ActionCable
   module Connection
     # Wrap the real socket to minimize the externally-presented API
     class WebSocket
-      def initialize(env, event_target, event_loop, client_socket_class)
-        @websocket = ::WebSocket::Driver.websocket?(env) ? client_socket_class.new(env, event_target, event_loop) : nil
+      def initialize(env, event_target, event_loop, client_socket_class, protocols: ActionCable::INTERNAL[:protocols])
+        @websocket = ::WebSocket::Driver.websocket?(env) ? client_socket_class.new(env, event_target, event_loop, protocols) : nil
       end
 
       def possible?
@@ -24,6 +24,10 @@ module ActionCable
         websocket.close
       end
 
+      def protocol
+        websocket.protocol
+      end
+
       def rack_response
         websocket.rack_response
       end