title: How do I pass dynamic variables into templates in Meteor?
body: <p>Using data of the form:</p>
  
  <pre><code>users = 
    _id: 'foo'
    books: [
      {name: 'book1'}
      {name: 'book2'}
    ]
  </code></pre>
  
  <p>&nbsp;</p>
  
  <pre><code>&lt;template name="user"&gt;
    {{#each get_users}}
      {{&gt; shelf}}
    {{/each}}
  &lt;/template&gt;
  
  &lt;template name="shelf"&gt;
    {{#each books}}
      {{&gt; book}}
    {{/each}}
  &lt;/template&gt;
  
  &lt;template name="book"&gt;
    &lt;div contenteditable="true" data-id="{{_id}}"&gt;{{name}}&lt;/div&gt;
  &lt;/template&gt;
  </code></pre>
  
  <p>I want <code>_id</code> in the <code>book</code> template to refer to the <code>_id</code> of the user, but <code>_id</code> is not in scope inside the <code>book</code> template. I'd like to be able to do something like <code>{{&gt; book _id}}</code>, but that doesn't work, I think because <code>book</code> can only have one argument, and that is each <code>{name: 'book1'}</code> doc.</p>