Actioncable

Installation

Add the :actioncable dependency to your mix.exs file

defp deps() do
  [
    {:actioncable, "~> 0.1.0"}
  ]

Then, run mix deps.get in your shell to fetch the new dependencies.

Usage

• Add this configuration in config/config.ex,

config :your_application_name, Your_application_name_Web.Endpoint,
  check_origin: false,
    http: [
      dispatch: [
        {:_, [
          {"/cable", Actioncable.SocketHandler, []},
          {:_, Phoenix.Endpoint.Cowboy2Handler, {Your_application_name_Web.Endpoint, []}}
        ]}
      ]
    ],
    subprotocols: ["actioncable-v1-json"]

It will redirect every url ending by "/cable" to Cowboy Websocket Handler. Other url will be redirect in your Endpoint as usual.

• Start a Redix connection named :redix_ac, it will be used for storing websocket pid in corresponding channel.

In your application.ex :

def start(_type, _args) do
  children = [
    %{
      id: Redix,
      start: {Redix, :start_link, ["redis://localhost:6379/15", [name: :redix_ac]]}
    }
  ]
end

Note: in this case, i'm using redis database number 15. If the server shut down brutally, you may want to clean the different channel. You can do the following (You have to be sure that your redis database -in this case the redis database 15- does not store any other data) :

def start(_type, _args) do
  children = [
    %{
      id: Redix,
      start: {Redix, :start_link, ["redis://localhost:6379/15", [name: :redix_ac]]}
    }
  ]
  opts = [strategy: :one_for_one, name: XXX.Supervisor]
  ret = XXX.start_link(children, opts)
  Redix.command!(:redix_ac, ["flushdb"])
  ret
end

It will clean redis database 15 at every start.