I’m trying to follow LiveBeat’s example of using PubSub to send messages to LiveViews. I’ve also read through a ton of topics here, so I’m not sure what I’m doing wrong…

I’m broadcasting on a PubSub topic that a LiveView is subscribed to. I think the topic and everything is wired up correctly, but the LiveView never sees the message (or shows a failure for not handling it properly.)

Here’s my PubSub setup:

defmodule Ido.Trips.PubSub do
  @moduledoc """
  PubSub for trips
  """

  # defined in application.ex
  @pubsub Ido.PubSub

  def broadcast_email_processed(element) do
    msg = %Ido.Trips.Events.EmailProcessed{element: element}
    broadcast!(element.trip_id, msg)
  end

  defp broadcast!(trip_id, msg) do
    Phoenix.PubSub.broadcast!(@pubsub, topic(trip_id), {__MODULE__, msg})
  end

  def subscribe_to_trip_id(trip_id) do
    Phoenix.PubSub.subscribe(@pubsub, topic(trip_id))
  end

  def unsubscribe_to_trip_id(trip_id) do
    Phoenix.PubSub.unsubscribe(@pubsub, topic(trip_id))
  end

  defp topic(trip_id) do
    "trip:#{trip_id}"
  end
end

I’m subscribing to it in a handle_params in my LiveView, not mount because I need the id of the Trip:

@impl true
  def handle_params(%{"id" => id} = params, _, socket) do
    if connected?(socket) do
      # make sure no duplicates
      Ido.Trips.PubSub.unsubscribe_to_trip_id(id)

      Ido.Trips.PubSub.subscribe_to_trip_id(id)
    end
...

@impl true
  def handle_info(
        {Ido.Trips.PubSub, %Ido.Trips.Events.EmailProcessed{element: element}},
        socket
      ) do
        {:noreply, put_flash(socket, :info, "An element was processed from email")}
  end

What did I mess up? I don’t have any warnings/errors in the console during startup or when I broadcast the message.

Thanks!