Talking with Hubot through Google Glass

For home automation I use Hubot, it’s something like a framework for creating chat bots, it’s very easy to use and rules for it can be written in CoffeeScript, like:

robot.hear /pause move/i, (res) ->
  exec 'player pause'
  res.send 'Sure!'

So I planned to create an app for phone, which would allow me to say “Ok Google, Hubot, next song”, or something similar. But it’s not possible, Android API not allow to create custom voice actions like “Hubot”, only commands from predefined list allowed.

But I remembered that I have useless Google Glass, which GDK API allows to create custom “Ok Glass” commands, like “Ok Glass, Hubot, next song”, at least in development mode with:

<uses-permission android:name="com.google.android.glass.permission.DEVELOPMENT" />

First of all I created Hubot adapter which support something like polling with simple API:

• POST /polling/subscribe/ with {} respond s{user: user} – subscribe to polling;
• POST /polling/message/ with {user: user, text: message-text} responds {ok: ok} – send message to bot;
• GET /polling/response/:user/ responds {responses: [response]} – get unread bot responses.

It’s not so interesting, written in CoffeeScript (Hubot requires it), code is very simple.

For Glass part I’ve used Kotlin with a few nice libraries:

• anko as sugar for Android API;
• kotson for working with JSON;
• fuel as HTTP client;
• kovenant for promises.

And it’s very great combination, with them making http request is much nicer than with java and just DefaultHttpClient, like:

Fuel.post("$url/polling/message/")
    .body(jsonObject("user" to user, "text" to text).toString())
    .header("Content-Type" to "application/json")
    .jsonPromise()
    .success { info("Message $text sent") }
    .fail { warn("Can't send message $text because $it") }

Just promises in comparison with Clojure core.async and Scala Akka it’s a bit way back, it’s like writing in pre ES7 JavaScript. So why Kotlin? It’s simpler to use on Android, struggling with dex errors with Scala isn’t fun. Performance is similar to apps written in Java, sometimes startup time of Clojure apps is annoying. And there’s far less magic then in Scala scaloid and Clojure Neko.

In action:

Sources on github.