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.

• :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.