Receives the socket params and authenticates the connection.

Socket params and assigns

Socket params are passed from the client and can be used to verify and authenticate a user. After verification, you can put default assigns into the socket that will be set for all channels, ie

{:ok, assign(socket, :user_id, verified_user_id)}

To deny connection, return :error.

See Phoenix.Token documentation for examples in performing token verification on connect.

Callback implementation for Phoenix.Socket.connect/2.

Identifies the socket connection.

Socket IDs are topics that allow you to identify all sockets for a given user:

def id(socket), do: "users_socket:#{socket.assigns.user_id}"

Would allow you to broadcast a "disconnect" event and terminate all active sockets and channels for a given user:

MyApp.Endpoint.broadcast("users_socket:" <> user.id, "disconnect", %{})

Returning nil makes this socket anonymous.

Callback implementation for Phoenix.Socket.id/1.