Configuration for a Slipstream websocket connection

Slipstream server process configuration is passed in with Slipstream.connect/2 (or Slipstream.connect!/2), and so all configuration is evauated and validated at runtime, as opposed to compile-time validation. You should not expect to see validation errors on configuration unless you force the validation at compile-time, e.g.:

# you probably don't want to do this...
defmodule MyClient do
  @config Application.compile_env!(:my_app, __MODULE__)

  use Slipstream

  def start_link(args) do
    Slipstream.start_link(__MODULE__, args, name: __MODULE__)
  end

  def init(_args), do: {:ok, connect!(@config)}

  ..
end

This approach will validate the configuration at compile-time, but you will be unable to change the configuration after compilation, so any secrets contained in the configuration (e.g. a basic-auth request header) will be compiled into the beam files.

See the docs for Slipstream.init/1 for a safer approach.

Options

• :uri - Required. The endpoint to which the websocket will connect. Schemes of "ws" and "wss" are supported, and a scheme must be provided. Either binaries or URI structs are accepted. E.g. "ws://localhost:4000/socket/websocket".

• :heartbeat_interval_msec (non_neg_integer/0) - The time between heartbeat messages. A value of 0 will disable automatic heartbeat sending. Note that a Phoenix.Channel will close out a connection after 60 seconds of inactivity (60_000). The default value is 30000.

• :upgrade_timeout_msec (non_neg_integer/0) - The time to wait for the server to respond to the WebSocket upgrade request once the connection has been opened. If the server does not respond within this time, the connection is closed and Slipstream.handle_disconnect/2 is invoked with {:error, :upgrade_timeout}. A value of 0 will disable the timeout. The default value is 10000.

• :headers - A set of headers to merge with the request headers when GETing the websocket URI. Headers must be provided as two-tuples where both elements are binaries. Casing of these headers is inconsequential. The default value is [].

• :serializer (atom/0) - A serializer module which exports at least encode!/1 and decode!/2. The default value is Slipstream.Serializer.PhoenixSocketV2Serializer.

• :json_parser (atom/0) - A JSON parser module which exports at least encode!/1 and decode!/1. The default value is Jason.

• :reconnect_after_msec (list of non_neg_integer/0) - A list of times to reference for trying reconnection when Slipstream.reconnect/1 is used to request reconnection. The msec time will be fetched based on its position in the list with Enum.at(reconnect_after_msec, try_number). If the number of tries exceeds the length of the list, the final value will be repeated. The default value is [10, 50, 100, 150, 200, 250, 500, 1000, 2000, 5000].

• :rejoin_after_msec (list of non_neg_integer/0) - A list of times to reference for trying to rejoin a topic when Slipstream.rejoin/3 is used. The msec time will be fetched based on its position in the list with Enum.at(rejoin_after_msec, try_number). If the number of tries exceeds the length of the list, the final value will be repeated. The default value is [100, 500, 1000, 2000, 5000, 10000].

• :mint_opts (keyword/0) - A keywordlist of options to pass to Mint.HTTP.connect/4 when opening connections. This can be used to set up custom TLS certificate configuration. See the Mint.HTTP.connect/4 documentation for available options. The default value is [protocols: [:http1]].

• :extensions (term/0) - A list of extensions to pass to Mint.WebSocket.upgrade/4. The default value is [].

• :test_mode? (boolean/0) - Whether or not to start-up the client in test-mode. See Slipstream.SocketTest for notes on testing Slipstream clients. The default value is false.

Note that a Phoenix.Channel defined with

socket "/socket", UserSocket, ..

Can be connected to at /socket/websocket.