1 files changed, 54 insertions, 0 deletions
diff --git a/actioncable/lib/action_cable/server/broadcasting.rb b/actioncable/lib/action_cable/server/broadcasting.rb
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+++ b/actioncable/lib/action_cable/server/broadcasting.rb
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+require 'redis'
+
+module ActionCable
+  module Server
+    # Broadcasting is how other parts of your application can send messages to the channel subscribers. As explained in Channel, most of the time, these
+    # broadcastings are streamed directly to the clients subscribed to the named broadcasting. Let's explain with a full-stack example:
+    #
+    #   class WebNotificationsChannel < ApplicationCable::Channel
+    #      def subscribed
+    #        stream_from "web_notifications_#{current_user.id}"
+    #      end
+    #    end
+    #
+    #    # Somewhere in your app this is called, perhaps from a NewCommentJob
+    #    ActionCable.server.broadcast \
+    #      "web_notifications_1", { title: 'New things!', body: 'All shit fit for print' }
+    #
+    #    # Client-side coffescript which assumes you've already requested the right to send web notifications
+    #    App.cable.subscriptions.create "WebNotificationsChannel",
+    #      received: (data) ->
+    #        new Notification data['title'], body: data['body']
+    module Broadcasting
+      # Broadcast a hash directly to a named <tt>broadcasting</tt>. It'll automatically be JSON encoded.
+      def broadcast(broadcasting, message)
+        broadcaster_for(broadcasting).broadcast(message)
+      end
+
+      # Returns a broadcaster for a named <tt>broadcasting</tt> that can be reused. Useful when you have a object that
+      # may need multiple spots to transmit to a specific broadcasting over and over.
+      def broadcaster_for(broadcasting)
+        Broadcaster.new(self, broadcasting)
+      end
+
+      # The redis instance used for broadcasting. Not intended for direct user use.
+      def broadcasting_redis
+        @broadcasting_redis ||= Redis.new(config.redis)
+      end
+
+      private
+        class Broadcaster
+          attr_reader :server, :broadcasting
+
+          def initialize(server, broadcasting)
+            @server, @broadcasting = server, broadcasting
+          end
+
+          def broadcast(message)
+            server.logger.info "[ActionCable] Broadcasting to #{broadcasting}: #{message}"
+            server.broadcasting_redis.publish broadcasting, ActiveSupport::JSON.encode(message)
+          end
+        end
+    end
+  end
+end