connect the dots

[setop]

I wanted to implement an example where I POST messages to an endpoint and all http client connected on sse endpoint receive them.

I managed to do it with "plug" and "phoenix_pubsub".
But I failed to put all pieces together using SSE.Stream and EventBus.

Here is my code:

Mix.install([
  {:bandit, "~> 1.1.3"},
  {:sse, "~> 0.4"},
  {:event_bus, ">= 1.6.0"},
  {:uuid, "~> 1.1"}
])

defmodule Router do
  
  use Plug.Router
  import SSE
  import EventBus
  alias SSE.Chunk
  alias EventBus.Model.Event

  @topic :inbox

  plug(Plug.Logger)
  plug(:match)
  plug(:dispatch)

  post "/inbox" do
    chunk = %Chunk{data: '{"a":"b"}'}
    event = %Event{id: UUID.uuid4(), data: chunk, topic: @topic}
    EventBus.notify(event)
    conn
    |> put_resp_content_type("application/json")
    |> send_resp(200, '{"result":"ok"}')
  end

  get "/" do
    conn
    |> put_resp_content_type("text/html")
    |> send_file(200, "index.html")
  end

  get "/sse" do
    chunk = %Chunk{data: "Hi there!"}
    EventBus.subscribe({MyEventSubscriber, [".*"]})
    loop_receive(conn)
  end
  
  def loop_receive(conn) do
    receive do
      {:post, chunk} ->
        conn
        |> SSE.stream({@topic,chunk})
        loop_receive(conn)
    end
  end

  match _ do
    send_resp(conn, 404, "not found")
  end
end

webserver = {Bandit, plug: Router, scheme: :http}
{:ok, _} = Supervisor.start_link([EventBus, webserver], strategy: :one_for_one)

# unless running from IEx, sleep idenfinitely so we can serve requests
unless IEx.started?() do
  Process.sleep(:infinity)
end

It fails with [warning] Topic(:inbox doesn't exist!) doesn't have subscribers when I post messages.

May need a little help :)