title: How to trigger ng-change on a select that contains a ng-repeat
body: <p>I have two select box, the second select box updates itself when the first select box changes.</p>
  
  <pre><code>&lt;label&gt;Region&lt;/label&gt;
  &lt;select ng-model="region" 
          ng-change="clear(1)" 
          ng-options="l.region for l in locations"
  &gt;&lt;/select&gt;
  &lt;br /&gt;
  &lt;label&gt;Country&lt;/label&gt;
  &lt;select ng-model='country'
          ng-change="clear(2)" 
          ng-options="c.country for c in region.countries"
  &gt;&lt;/select&gt;
  </code></pre>
  
  <p>My locations is a json object that looks like this : </p>
  
  <pre><code>[
    {region: "Europe", countries: [{country: "France"}, {country: "UK"}/*, ...*/]},
    {region: "Africa", countries: [{country: "Cameroon"}, {country: "Algeria"}]}
    /*, ...*/
  ]
  </code></pre>
  
  <p>This all works fine this way.</p>
  
  <p>It begins to be complicated when I want to set the value of  the first select box to Europe, and I want to trigger the ng-change event on the second select box.</p>
  
  <p>Any idea on how to do this? </p>