Elixir-Slack

This is a Slack Real Time Messaging API client for Elixir. You'll need aSlack API token which can be retrieved by following the Token GenerationInstructions or by creating anew bot integration.

Installing

Add Slack to your mix.exs dependencies function.

def application do
  [extra_applications: [:logger]]
end

def deps do
  [{:slack, "~> 0.23.6"}]
end

Upgrading from 0.x to 0.20+

The newest version of the Slack client introduces breaking changes with regards to starting and connecting to the Real Time Messaging API. rtm.start is now deprecated and has since been replaced with rtm.connect. This has removed the list of bots, channels, groups, users, and ims that are normally returned from rtm.start. Additionally, these lists are now rate-limited. In order to achieve relative parity to the old way of doing things, you'll need to make one change in your code:

Make additional calls to the Slack API to fetch bots, channels, groups, users, and IMs

Wherever you grab the passed in slack state, add in additional calls to populate these lists:

slack
|> Map.put(:bots, Slack.Web.Bots.info(%{token: token}) |> Map.get("bot"))
|> Map.put(:channels, Slack.Web.Channels.list(%{token: token}) |> Map.get("channels"))
|> Map.put(:groups, Slack.Web.Groups.list(%{token: token}) |> Map.get("groups"))
|> Map.put(:ims, Slack.Web.Im.list(%{token: token}) |> Map.get("ims"))
|> Map.put(:users, Slack.Web.Users.list(%{token: token}) |> Map.get("members"))

RTM (Bot) Usage

Define a module that uses the Slack behaviour and defines the appropriatecallback methods.

defmodule SlackRtm do
  use Slack

  def handle_connect(slack, state) do
    IO.puts "Connected as #{slack.me.name}"
    {:ok, state}
  end

  def handle_event(message = %{type: "message"}, slack, state) do
    send_message("I got a message!", message.channel, slack)
    {:ok, state}
  end
  def handle_event(_, _, state), do: {:ok, state}

  def handle_info({:message, text, channel}, slack, state) do
    IO.puts "Sending your message, captain!"

    send_message(text, channel, slack)

    {:ok, state}
  end
  def handle_info(_, _, state), do: {:ok, state}
end

To run this example, you'll want to call Slack.Bot.start_link(SlackRtm, [], "TOKEN_HERE") and run the project with mix run --no-halt.

You can send messages to channels using send_message/3 which takes the messageas the first argument, channel/user as the second, and the passed in slackstate as the third.

The passed in slack state holds the current user properties as me, teamproperties as team, and the current websocket connection as socket.

If you want to do things like trigger the sending of messages outside of yourSlack handlers, you can leverage the handle_info/3 callback to implement anexternal API.

This allows you to both respond to Slack RTM events and programmatically controlyour bot from external events.

{:ok, rtm} = Slack.Bot.start_link(SlackRtm, [], "token")
send rtm, {:message, "External message", "#general"}
#=> {:message, "External message", "#general"}
#==> Sending your message, captain!

Slack has a lot of message types so it's a good idea to define a callback likeabove where unhandled message types don't crash your application. You can find alist of message types and examples on the RTM API page.

You can find more detailed documentation on the Slack hexdocspage.

Web API Usage

The complete Slack Web API is implemented by generating modules/functions fromthe JSON documentation. You can view this project's documentation for moredetails.

There are two ways to authenticate your API calls. You can configure api_tokenon slack that will authenticate all calls to the API automatically.

config :slack, api_token: "VALUE"

Alternatively you can pass in %{token: "VALUE"} to any API call inoptional_params. This also allows you to override the configured api_tokenvalue if desired.

Quick example, getting the names of everyone on your team:

names = Slack.Web.Users.list(%{token: "TOKEN_HERE"})
|> Map.get("members")
|> Enum.map(fn(member) ->
  member["real_name"]
end)

Web Client Configuration

A custom client callback module can be configured for cases in which you need extra controlover how calls to the web API are performed. This can be used to control timeouts, or to add additionalcustom error handling as needed.

config :slack, :web_http_client, YourApp.CustomClient

All Web API calls from documentation-generated modules/functions will call post!/2 with the generated urland body passed as arguments.

In the case where you only need to control the options passed to HTTPoison/hackney, the default client acceptsa keyword list as an additional configuration parameter. Note that this is ignored if configuring a custom client.

See HTTPoison docs for a list of available options.

config :slack, :web_http_client_opts, [timeout: 10_000, recv_timeout: 10_000]

Testing

For integration tests, you can change the default Slack URL to your fake Slackserver:

config :slack, url: "http://localhost:8000"