title: How to do multiline comment with conditional statements in ember.js script handlebars?
body: <p>I'm learning ember.js and would like to sometimes deactivate some chunks of code. I know <code>{{! }}</code> works for single-line commenting inside <code>&lt;script type="text/x-handlebars"&gt;</code>, but I can't make it work for multi-line commenting. Maybe because I have conditional statements inside.</p>
  
  <pre><code>&lt;script type="text/x-handlebars" id="stuff"&gt;
      {{!
        {{#if length}}
          foobar
        {{/if}}
      }}
  &lt;/script&gt;
  </code></pre>
  
  <p>but then I got this error:</p>
  
  <pre><code>Uncaught Error: Parse error on line xx:
  ...ngth}}    foobar  {{/if}}}}    {{ o
  ---------------------^
  Expecting 'EOF', got 'OPEN_ENDBLOCK' 
  </code></pre>
  
  <p>I also tried using <code>&lt;!-- ... --&gt;</code>, while the section is not shown, but I also get this error:</p>
  
  <p><em>Uncaught Error: Cannot perform operations on a Metamorph that is not in the DOM</em></p>
  
  <p>this error doesn't show up if I just delete that chunk of code.</p>