Merge pull request #24224 from danielrhodes/actioncable-websocket-protocols

ActionCable protocol negotiation

3 files changed, 50 insertions, 16 deletions

diff --git a/actioncable/app/assets/javascripts/action_cable/connection.coffee b/actioncable/app/assets/javascripts/action_cable/connection.coffee
index 3a139acf3a..822f25ac1d 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("Attempted 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()
 #