title: AngularJS ngOptions filter array by boolean field
body: <p>I have this array:</p>
  
  <pre><code>    this.chapters = {
           1: { name: 'Chapter 1', show: false },
           2: { name: 'Chapter 2', show: true },
           3: { name: 'Chapter 3', show: true }
      };
  </code></pre>
  
  <p>And I want to show only chapters whose show value is true in this select</p>
  
  <pre><code>&lt;select ng-model="cart.newchapter" 
          ng-options="v.name for (k, v) in cart.chapters"&gt;&lt;/select&gt;
  </code></pre>
  
  <p>Now it's showing all chapters, but I need to filter them. I've been trying to apply filter but It didn't work. Can you help me? Oh! I can't change boolean type of. </p>