gistfile1.rb

#!/usr/bin/ruby

$:.unshift '/home/rubys/git/wunderbar/lib'
$:.unshift '/home/rubys/git/opal/lib'
$:.unshift '/home/rubys/git/opal-browser/lib'

### what "require 'wunderbar/opal-browser'" will ultimately do for you:
require 'wunderbar/opal'
require 'opal/browser'

Wunderbar::Asset.script :name => 'opal-browser.js',
  :contents => Opal::Builder.build('browser')
###

_html do
  _head do
    _title 'Opal demonstration'
  end

  _body do
    _span 0
    _button 'increment'
    _script do
      span = $document.at('span')
      span.content = span.content.to_i+1
    end
  end
end