Oak

A very opinionated kiosk UI application based on electron.

Rationale

Most of the electron project if focused around desktop application development, which is great! But when you are dealing with public computing (ATM machines, airline ticketing, movie theater ticket vendors, etc), you don't really need all the features a traditional desktop application requires. This includes things like drag-n-drop, system menus, desktop icons, etc.

The job of the oak module is to give a really easy way to make a kiosk application with modern web technology, so that it's repeatable, scalable, and easy to rapidly prototype for production. It also takes care of a few common Electron work flow issues that aren't immediately apparent, but effect kiosks in a big way. A good example of this would be errors displaying in a dialog window.

Prerequisites

We recommend that you install Nodejs via Node Version Manager: https://github.com/creationix/nvm#install--update-script

After you install and follow the instructions at the end (adding nvm to your path),

$ nvm install 14.16.1
$ nvm use 14.16.1

Install

The recommended way is to install globally, so it's in your $PATH

$ npm install -g oak

If you aren't installing globally, you will have the oak entrypoint in your local node_modules directory

$ npm install --save-dev oak # make sure this is saved in your devDependencies
$ node_modules/.bin/oak

Rebuilding native modules

If you are using native node modules, you will generally need to rebuild them to function against the version of node running in oak.

$ cd myApp/
$ npm install
# if you are using oak globally
$ oak-rebuild .

if you are using oak in devDependencies

$ cd myApp/
$ npm install
$ node_modules/.bin/oak-rebuild .

on Mac OSX

You will need to have the XCode Commandline Tools installed. If you don't, make sure to install XCode and then run:

$ xcode-select --install

Quick Start

The most minimal example, this will launch a fullscreen app. This will also inject the oak object into the client side window.oak

// index.js

const oak = require('oak')

// when oak is ready, we can tell it to load something
oak.on('ready', () => {
  // loading takes an options object with a `url`, second parameter is an optional callback
  oak.load({
    url: 'http://www.mywebapp.com'
  }) // or callback)
})

$ oak index.js

When you start your app, the oak module is automatically resolved in modules, meaning you don't need to include it in your package.json file. This is similar to the way electron exposes it's own modules automatically.

Load just a URL

You can use any fully qualified URL, to simply launch a fullscreen webpage.

$ oak http://www.zivelo.com/

Load a file

You can load a single .html file as well, but just have a fully qualified path.

$ oak file://${pwd}/path/to/index.html

Load via JSON

You can also load a .json file, which contains the same configuration you would pass to oak.load().

Example: myOptions.json

{
  "url": "http://www.zivelo.com",
  "fullscreen": false,
  "ontop": false
}

$ oak myOptions.json

Load via CLI

$ oak --help

Usage: oak [options] [command] <uri>

If you load oak with a script path, no commandline options will apply automatically.

Options:
  -V, --version               output the version number
  -b, --background [String]   Hex background color for initial window. Example: #f0f0f0 (default: "#000000")
  -f, --fullscreen [Boolean]  Set the window to full width and height. This overrides the --size option (default: true)
  -k, --kiosk [Boolean]       Kiosk mode, which is fullscreen by default. On OSX this will cause the workspace to shift to a whole new one (default: false)
  -s, --size [String]         Window size in WIDTHxHEIGHT format. Example: 1024x768. This will over ride both --kiosk and --fullscreen
  -x, --x [Number]            Window X position (default: 0)
  -y, --y [Number]            Window Y position (default: 0)
  -t, --title [String]        Window title (default: "Oak")
  -t, --ontop [Boolean]       Start window ontop of others (default: true)
  -D, --display [Number]      Display to use (default: 0)
  -S, --shortcut [List]       Register shortcuts, comma separated. reload,quit (default: [])
  -u, --useragent [String]    User-Agent string
  -F, --frame [Boolean]       Show window frame (default: false)
  --show [Boolean]            Show window on start (default: true)
  -n, --node [Boolean]        Enable node integration (default: false)
  -i, --insecure [Boolean]    Allow insecure connections (not recommended) (default: false)
  -c, --cache [Boolean]       Use standard caching, setting this to false has the same effect as the --disable-http-cache chrome flag (default: true)
  -d, --debugger [Boolean]    Open chrome dev tools on load (default: false)
  -h, --help                  output usage information

Commands:
  version [options] [type]    Prints version, options are are `all`, `oak`, `electron`, `node`

Methods

oak.load(options[, callback])

Most of these options are wrapping electron.js BrowserWindow options, but some are specific to our kiosk use-case. This method returns the Window object

• options: Object

  • url: - Not optional

    • String - The url option is the only one required, and will load any valid URI

    // load a local HTML file
    url: 'file://' + require('path').join(__dirname, 'index.html')
    
    // load your own webserver
    url: 'http://localhost:8080'

  • title: String OAK- The window title

  • display: Number 0 - Your display number, and defaults to your main display

  • fullscreen: Boolean true - Set the window to max height and width

  • kiosk: Boolean false - Sets kiosk mode

  • ontop: Boolean true - Set the window to be always on top of others

  • show: Boolean true - Start the window shown, this will also show the window whenever it is reloaded

  • size: String - Window size in WIDTHxHEIGHT format. Example: 1024x768. This will over ride both kiosk and fullscreen

  • x: Number 0 - X position

  • y: Number 0 - Y position

  • shortcut Object

    • reload Boolean false - enable CommandOrControl+Shift+R to reload the window
    • quit Boolean false - enable CommandOrControl+Shift+X to close the app

  • background: String #000000 - Hex color of the window background

  • frame: Boolean false - Show window frame

  • scripts: Array path - Local node scripts or modules to load into the window during pre-dom phase. This can be a object with name and path if you want the window.whatever script to be named

  • flags: Array - Chrome launch flags to set while starting the window

  • insecure Boolean false - allow running and displaying insecure content (not recommended at all)

  • sslExceptions Array - Bypass SSL security for specific hosts. This uses a host pattern. Example: *.mysite.com

  • cache Boolean true - Enable HTTP cache flag for chrome

  • userAgent: String - Defaults to 'Oak/' + oak.version

  • callback: [Function] - Executed when the ready function has fired

oak.getDisplays()

Returns the current displays, and their metadata. You can use the id property to specify a window in oak.load properties. An example response:

[
  {
    "id": 0,
    "bounds": {
      "x": 0,
      "y": 0,
      "width": 1920,
      "height": 1080
    },
    "workArea": {
      "x": 0,
      "y": 0,
      "width": 1920,
      "height": 1080
    },
    "size": {
      "width": 1920,
      "height": 1080
    },
    "workAreaSize": {
      "width": 1920,
      "height": 1080
    },
    "scaleFactor": 1,
    "rotation": 0,
    "touchSupport": "unknown"
  }
]

oak.sslExceptions

Bypass SSL security for specific hostnames. This is an array of host patterns, which follow the glob pattern of minimatch.

oak.sslExceptions = [
  '*.example.com',
  'subdomain.example.com'
]

oak.log

Returns a pino instance for logging. By default the DEBUG environment variable is set to false, and will only log messages with the level of error or greater.

If you run DEBUG=true, you will get anything with a debug level or higher, including verbose window information.

Window object

oak.load() returns a Window object with methods and events. Each instance of oak.load() returns a unique object for that window, and the methods are mirrored for both the node side and client (renderer) side.

.send(event[, payload])

Send events to the window

• event: String - the event namespace, delimited by .

• payload: Any - whatever data you want to send along.

  Example: window.send('myEvent', { foo: 'bar' })

.on(event, callback)

This is an instance of EventEmitter2

• ready - Will emit the ready event, and also execute the optional callback
• reload - The window has reloaded
  • oldUrl - previous URL
  • newUrl - new resolved URL
• location - A window location change has happened (will not fire if window.location = X is called in the rendered)
  • oldUrl - previous URL
  • newUrl - new resolved URL
  • oldSession - previous session ID
  • newSession - new session ID
• loadFailed - The window load failed
  • opts: Object - original options used
  • err: Error
• unresponsive - The window has hung and become unresponsive

.location(url)

Set the URL location of the window. This will fire a location event.

• url: String - URL to load

.reload(cache)

Reload the window.

• cache: Boolean false - Reload the window without cache. This will fire a reload event.

.debug()

Toggle the chrome debugger

.show()

Show the window

.hide()

Hide the window

.focus()

Set the desktop focus to this window

.disableZoom()

Disables pinch zoom or any window zoom in the browser window

Window properties

id

Unique id of that window.

Window events

The window fires events from electrons BrowserWindow and webContents. The only event fired from that set into the renderer is dom-ready.

note: If you do a send of the same event from the renderer side, it will look like the same event coming from electron events. So be careful and watch your namespaces for conflicts!

Environment variables

If you would like to use

Examples

Check out the examples folder!

Docker

To get started running oak in Docker... you will need to have Docker installed. You can install from here, or on Linux systems, run this script:

curl -sSL https://get.docker.com/ | sh
# add your user to the docker group
sudo usermod -aG docker $(whoami)

You will also need an X server running (xorg). If you are on OSX, go ahead and follow the steps below to get setup.

On Linux

This example is for debian based systems, you can accomplish the same by getting docker and docker-compose running yourself.

1. Install python-setuptools

   sudo apt-get install -y python-setuptools

2. Install pip

   sudo easy_install pip

3. Install docker-compose

   pip install docker-compose>=1.8.0

4. Allow your X server to allow outside connections. Make sure to disable this after you are finished!

   xhost +
   docker-compose up

   You should turn off your open xhost after you are finished developing.

   docker-compose down
   xhost -

On OSX

I'm not going to lie... this is a pain in the ass.

OSX doesn't have xorg, or any build in X server by default. You are going to be using socat to proxy Xquartz via TCP so that you can use your IP address the docker container. It may be easier to start up a VM running ubuntu or debian.

1. Install homebrew

   Homebrew is a easy way to install linux packages on OSX. In your Terminal app:

   /usr/bin/ruby -e "$(curl -fsSL https://raw.githubusercontent.com/Homebrew/install/master/install)"

2. Install socat and python

   • socat will be needed to forward your X server socket, in order to display a window on your desktop.

     brew install socat

   • python is useful for a number of reasons, but in our case, a means to get docker-compose. When you install python, you get the pip program along with it.

     brew install python

3. Install docker-compose

   Rather than using straight docker commands, we use docker-compose to simplfy orchestrating multiple containers. docker-compose uses a .yml file to describe docker commands and run them.

   pip install docker-compose
   

4. Install XQuartz, which is a X server for OSX.

5. Open XQuartz, go to Preferences > Security > Allow connections from network clients.

6. In Terminal, run socat to proxy your X server connection via TCP:

   socat TCP-LISTEN:6000,reuseaddr,fork UNIX-CLIENT:\"$DISPLAY\"

   After you run this, it will be waiting for connections, so don't close this Terminal window. ​

7. Edit docker-compose.osx.yml

   Replace the X's with your IP address. This will resolve your socat connection to the container, which is proxying XQuartz.

   environment:
     - DISPLAY=XXX.XXX.XXX.XXX:0

   If your IP address was 192.168.0.5, the line would be DISPLAY=192.168.0.5:0 . Don't forget the :0 and the end, that specifys that it's the first display, not a port.

8. In your oak directory, run docker-compose -f docker-compse.osx.yml up

On Windows

Sorry but you are a little on your own as far as an X server goes! In the future we may update this readme to provide info for developing on Windows. In the mean time... Cygwin?