@callback handle_init(payload :: map(), socket()) :: init()

Handle the connection_init message sent by the socket implementation. This will receive the payload from the message, defaulting to an empty map if received from the client.

This can be used for custom authentication/authorization, using Absinthe.GraphqlWS.Util.assign_context/2 to modify the Absinthe context.

In case the user is authenticated through session cookies, the session data may be accessed in the socket's :connect_info field. Note that you need to send a _csrf_token param in the URL to effectively receive the session info (or else the session will be nil). For more information, visit the Phoenix Endpoint docs: https://hexdocs.pm/phoenix/Phoenix.Endpoint.html#socket/3-common-configuration

example

Example

defmodule MySocket do
  use Absinthe.GraphqlWS.Socket, schema: MySchema

  def handle_init(%{"user_id" => user_id}, socket) do
    case find_user(user_id) do
      nil ->
        {:error, %{}, socket}
      user ->
        socket = assign_context(socket, current_user: user)
        {:ok, %{name: user.name}, socket}
    end
  end
end

@callback handle_message(params :: term(), socket()) :: reply_message()

Handles messages that are sent to this process through send/2, which have not been caught by the default implementation. It must return a reply_message/0.

If pushing content to the websocket, it must return a tuple in the form {:push, {:text, message}, socket}, where message is JSON that represents a valid grapql-ws message.

example

Example

alias Absinthe.GraphqlWS.Message

def handle_message({:thing, thing}, socket) do
  {:ok, assign(socket, :thing, thing)}
end

def handle_message({:send, id, payload}, socket) do
  {:push, {:text, Message.Next.new(id, payload)}, socket}
end

def handle_message(_msg, socket) do
  {:ok, socket}
end