Actioncable broadcasts not hitting Received JS function

actioncable, ruby-on-rails

Solution

First, check your frames. Are you sure you're getting the messages you want?

Then, in your channel you should set an ID to your subs. If you have a stream that is related to a model, then the broadcasting used can be generated from the model and channel.

class DashboardChannel < ApplicationCable::Channel
  def subscribed
    post = Post.find(params[:id])
    stream_for post
  end
end

Then you can broadcast to your channel like so

`DashboardChannel.broadcast_to(@post, @comment)`

Otherwise, you should do the following:

class DashboardChannel < ApplicationCable::Channel
  def subscribed
    stream_from 'dashboard_channel'
  end
end

But this is a bad practice, because you won't be able to define which user transmits to your server.

Problem

I have been trying to get a rails app together to replace a nastily coded php monstrosity. The current incarnation is pulling data from a non-Rails db, putting it into the Rails db and then displaying it in the views. The db is mainly populated with temperature readings that are added every few seconds. I can display a static-ish page in Rails with no problems but, trying to add ActionCable/realtime data has proven problematic. MOST things seem to be working properly but, when I broadcast to my channel, it does not seem to hit the Received function in the mychannel.coffee. My Setup: Server - passenger (bundle exec passenger start) Jobs - Resque ActionCable - Redis Data is imported from the legacydb by a job that grabs the raw SQL and creates new records. After this, another job broadcasts to the channel. The problems are coming from ActionCable, I think. All examples that I can find require user input to trigger the JS, it seems. However, I am trying to trigger things strictly from the server side. This job: ``` class DatabroadcastJob < ApplicationJob queue_as :default self.queue_adapter = :resque def perform ActionCable.server.broadcast 'dashboard_channel', content: render_thedata end private def render_thedata dataArr =[Data1.last, Data2.last, Data3.last] ApplicationController.renderer.render(partial: 'dashboard/data_tables', locals: {item: dataArr}) end end ``` Works. It works. I see the broadcast hitting the dashboard_channel. However, nothing in the dashboard.coffee gets triggered by the broadcast. This is incredibly confusing. Dashboard.coffee ``` App.dashboard = App.cable.subscriptions.create "DashboardChannel", connected: -> # Called when the subscription is ready for use on the server disconnected: -> # Called when the subscription has been terminated by the server received: (data) -> # Called when there's incoming data on the websocket for this channel alert data['content'] ``` Nothing happens. The logs show the broadcast but nothing hits dashboard.coffee and raises an alert in browser. Am I thinking about this the wrong way because of all of the chat examples? Is there another place where I grab the broadcast and push it to subscribers when only making server side changes? If any other info is needed to address this, please let me know. This issue has been driving me mental for days now.

Original source