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 that's fit for print" }
#
# # Client-side CoffeeScript, 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 broadcasting. It'll automatically be JSON encoded.
def broadcast(broadcasting, message)
broadcaster_for(broadcasting).broadcast(message)
end
# Returns a broadcaster for a named broadcasting that can be reused. Useful when you have an object that
# may need multiple spots to transmit to a specific broadcasting over and over.
def broadcaster_for(broadcasting)
Broadcaster.new(self, broadcasting)
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.pubsub.broadcast broadcasting, ActiveSupport::JSON.encode(message)
end
end
end
end
end