title: how to select multiple checkboxes in ionic
body: <p>I am using ionic framework for my app development and want to select multiple checkboxes on click of header checkbox or button.</p>
  
  <pre><code>    &lt;ion-list&gt;
        &lt;ion-checkbox ng-model="filter.color"&gt;Colors&lt;/ion-checkbox&gt;
        &lt;ion-checkbox ng-model="filter.blue"&gt;Red&lt;/ion-checkbox&gt;
        &lt;ion-checkbox ng-model="filter.yellow"&gt;Yellow&lt;/ion-checkbox&gt;
        &lt;ion-checkbox ng-model="filter.pink"&gt;Pink&lt;/ion-checkbox&gt;
  
        &lt;ion-checkbox ng-model="filter.number"&gt;Number&lt;/ion-checkbox&gt;
        &lt;ion-checkbox ng-model="filter.one"&gt;1&lt;/ion-checkbox&gt;
        &lt;ion-checkbox ng-model="filter.two"&gt;2&lt;/ion-checkbox&gt;
        &lt;ion-checkbox ng-model="filter.three"&gt;3&lt;/ion-checkbox&gt;
      &lt;/ion-list&gt;
  </code></pre>
  
  <p>When I click on "Colors", all three three checkboxes should be clicked. And when I uncheck any one of them, "Colors" should be unchecked as well and only the other two should remain.</p>
  
  <p>I achieved this using normal HTML checkboxes and javascript, but a little unsure on how to do it ionic.</p>
  
  <p>Please Help.</p>
  
  <p>Thanks</p>