title: Firefox trying to download json from grails
body: <p>I have a grails controller whose last line is</p>
  
  <pre><code>render results as JSON
  </code></pre>
  
  <p>It is being rendered to an iframe. When firefox processes this, it tries to download the json file. Is this normal? The only way I've been able to get around this is to convert it to a string and then handle it on the javascript side.</p>