Behaviour for modules that handle decoded Polymarket websocket events.

A handler module is injected into the websocket through its start options (see Polymarket.WebSocket.start_link/1) and is invoked by Polymarket.WebSocket.MessageHandler for every event that is successfully decoded off the feed.

A handler typically performs side effects with the event (persisting it, forwarding it, and so on) and returns {:noreply, state}. It may also return {:reply, frame, state} to send a frame back over the websocket, for example to subscribe to additional assets in response to an event.

Example

defmodule MyHandler do
  @behaviour Polymarket.WebSocket.Handler

  @impl true
  def handle_event(%Polymarket.Schemas.PriceChangeEvent{} = event, state) do
    Logger.info("price change: #{inspect(event)}")
    {:noreply, state}
  end

  def handle_event(_event, state), do: {:noreply, state}
end