title: Filtering an ng-repeat list based on a sub-object property
body: <p>jsfiddle <a href="http://jsfiddle.net/KfSBq/">http://jsfiddle.net/KfSBq/</a></p>
  
  <p>By sub-object I mean that the objects I am displaying with ng-repeat all contain a list of objects within themselves, and I am looking to filter based on the property of one of those sub-objects. </p>
  
  <p>This alone was quite straightforward to do. I have an object of <code>dailies</code>, each containing a <code>date</code> and an <code>entries</code> list of objects:</p>
  
  <pre><code>function Ctrl($scope) {
      $scope.dailies = [{date: new Date('07/07/2013'), 
                         entries: [{category: 'A', note:'Lorem ipsum'}, 
                                   {category: 'B', note: 'Lorem ipsum'}]},
                        {date: new Date('05/02/2013'), 
                         entries: [{category: 'A', note: 'Lorem ipsum'}]}];
  }
  </code></pre>
  
  <p>I display them, filtering by category:</p>
  
  <pre><code>&lt;div ng-controller="Ctrl"&gt;
          &lt;div class="daily" ng-repeat="daily in dailies | orderBy:'-date' "&gt;
              {{ daily.date | date:'dd/MM/y' }}
              &lt;div class="entry" ng-repeat="entry in daily.entries | filter:{ category: 'B'} "&gt;
                  &lt;span&gt;{{ entry.category }}&lt;/span&gt;, &lt;span&gt;{{ entry.note }}&lt;/span&gt;
              &lt;/div&gt;
          &lt;/div&gt;
      &lt;/div&gt;
  </code></pre>
  
  <p>My issue here is that the daily objects that now contain no entries at all are still displayed. How do I achieve a situation where, if the filtering makes the <code>entries</code> list of a <code>daily</code> empty, that <code>daily</code> is not displayed either?</p>