How to use handle_info() from worker in Phoenix Channel?

Question

I've created working worker, that gets messages from Arduino in :elixir_serial handler, but now I want to use it in Channel to broadcast received data, can I inject socket to :elixir_serial handle_info()?

defmodule MyApp.Serialport do
  require Logger
  use GenServer

  def start_link() do
    GenServer.start_link(__MODULE__, [])
  end

  def init([]) do
    work()
    {:ok, []}
  end

  defp work do
    {:ok, serial} = Serial.start_link
    Serial.open(serial, "/dev/tty.arduino")
    Serial.set_speed(serial, 9600)
    Serial.connect(serial)
    Logger.debug "pid #{inspect serial}"
  end

  def handle_info({:elixir_serial, serial, data}, state) do
    Logger.debug "received :data #{inspect data}"
    {:noreply, state}
  end
end

Do you have any suggestions about how to improve worker code, eg. Gen_Server is necessary?

Answer 1

When you receive data, broadcast it to the channel's topic:

def handle_info({:elixir_serial, serial, data}, state) do
  Logger.debug "received :data #{inspect data}"
  MyApp.Endpoint.broadcast("some:topic", "serial_data", %{data: data}

  {:noreply, state}
end

You don't want to pass the actual socket because it could disappear any time and reconnect under a new process. Use the topic the socket is subscribed to instead and you will broadcast the data to anyone wanting to know about it.