broadcast.ex

defmodule App.Worker do
  
  def do_work(topic, user) do
     # async work goes here
     App.Endpoint.broadcast! topic, "work_done", %{ "user" => user }
  
  end
end
  
defmodule App.Channel do
  use App.Web, :channel
  
  # Intercept broadcast messages you're interested in
  intercepts ["work_done"]
  
  # boilerplate code here
  
  # Do some work
  def handle_in("do_work", _params, socket) do
    App.Worker.do_work(socket.topic, socket.assigns[:user])
    
    { :reply, :ok, socket }
  end
  
  # Handle the intercept
  def handle_out("work_done", params, socket) do
    if socket.assigns[:user] == params["user"] do
      push socket, "work_done", %{}
    end
    { :noreply, socket }
  end
  
end