title: Respond immediately to textarea changes in Dart
body: <p>I've got this in my html file:</p>
  
  <pre><code>&lt;textarea id="inputbox" placeholder="type here"&gt;&lt;/textarea&gt;
  </code></pre>
  
  <p>What's the correct way to wire up a handler that will fire immediately whenever the content of the textarea changes? (whether by keyboard, mouse/clipboard, speech input, brainwave reader, etc)</p>
  
  <p>I tried:</p>
  
  <pre><code>  query("#inputbox").on.change.add(handler)
  </code></pre>
  
  <p>but (at least on Dartium) it only fires after you tab out of the field.</p>
  
  <p>The purpose is to update a "live preview" window, similar to the way Stackoverflow renders Markdown output while you type.</p>