From 5954fd1e0aa907e07ffff932aedc51109d4ce56d Mon Sep 17 00:00:00 2001 From: Lachlan Sylvester Date: Wed, 22 Jul 2015 11:03:47 +1000 Subject: add broadcast_to and stream_for methods as per #26 --- lib/action_cable/channel/streams.rb | 37 +++++++++++++++++++++++++++++-------- 1 file changed, 29 insertions(+), 8 deletions(-) (limited to 'lib/action_cable/channel/streams.rb') diff --git a/lib/action_cable/channel/streams.rb b/lib/action_cable/channel/streams.rb index 6a3dc76c1d..f711b065ca 100644 --- a/lib/action_cable/channel/streams.rb +++ b/lib/action_cable/channel/streams.rb @@ -1,7 +1,7 @@ module ActionCable module Channel # Streams allow channels to route broadcastings to the subscriber. A broadcasting is an discussed elsewhere a pub/sub queue where any data - # put into it is automatically sent to the clients that are connected at that time. It's purely an online queue, though. If you're not + # put into it is automatically sent to the clients that are connected at that time. It's purely an online queue, though. If you're not # streaming a broadcasting at the very moment it sends out an update, you'll not get that update when connecting later. # # Most commonly, the streamed broadcast is sent straight to the subscriber on the client-side. The channel just acts as a connector between @@ -12,7 +12,7 @@ module ActionCable # def follow(data) # stream_from "comments_for_#{data['recording_id']}" # end - # + # # def unfollow # stop_all_streams # end @@ -23,23 +23,37 @@ module ActionCable # # ActionCable.server.broadcast "comments_for_45", author: 'DHH', content: 'Rails is just swell' # - # If you don't just want to parlay the broadcast unfiltered to the subscriber, you can supply a callback that let's you alter what goes out. + # If you have a stream that is related to a model, then the broadcasting used can be generated from the model and channel. + # The following example would to subscribe to a broadcasting that would be something like `comments:Z2lkOi8vVGVzdEFwcC9Qb3N0LzE` + # + # class CommentsChannel < ApplicationCable::Channel + # def subscribed + # post = Post.find(params[:id]) + # stream_for post + # end + # end + # + # You can then broadcast to this channel using: + # + # CommentsChannel.broadcast_to(@post) + # + # If you don't just want to parlay the broadcast unfiltered to the subscriber, you can supply a callback that let's you alter what goes out. # Example below shows how you can use this to provide performance introspection in the process: # # class ChatChannel < ApplicationCable::Channel # def subscribed # @room = Chat::Room[params[:room_number]] - # - # stream_from @room.channel, -> (message) do + # + # stream_for @room, -> (message) do # message = ActiveSupport::JSON.decode(m) - # + # # if message['originated_at'].present? # elapsed_time = (Time.now.to_f - message['originated_at']).round(2) - # + # # ActiveSupport::Notifications.instrument :performance, measurement: 'Chat.message_delay', value: elapsed_time, action: :timing # logger.info "Message took #{elapsed_time}s to arrive" # end - # + # # transmit message # end # end @@ -63,6 +77,13 @@ module ActionCable logger.info "#{self.class.name} is streaming from #{broadcasting}" end + # Start streaming the pubsub queue for the model in this channel. Optionally, you can pass a + # callback that'll be used instead of the default of just transmitting the updates straight + # to the subscriber. + def stream_for(model, callback = nil) + stream_from(broadcasting_for([ channel_name, model ]), callback) + end + def stop_all_streams streams.each do |broadcasting, callback| pubsub.unsubscribe_proc broadcasting, callback -- cgit v1.2.3