mruby with NPAPI plugin

sample.html

<script id="ruby_script" type="text/ruby">
#<![CDATA[
  num = 0
  1000.times do |i|
    num += i
  end
  hash = { result: num, input: $input }  # $input has JavaScript function.
  hash[:input].call({ a: num })  # JS function is called.
  $result = hash[:result]
#  ]]>
</script>

<script type="text/javascript">
// Global variable $input is shared in mruby and JavaScript.
$input = function(i){
  add("test: " + i.a);  // i is JS object converted from mruby hash.
};

// Add div element.
function add(str)
{
  var elem = document.createElement("div");
  document.getElementById("result").appendChild(elem);
  var text_elem = document.createTextNode(str);
  elem.appendChild(text_elem);
}
</script>

<form>
  <!-- 'ruby(id)' method runs mruby script in script tag. -->
  <input type=button value="test" onclick='alert(ruby("ruby_script"))' />
</form>