title: Does Aurelia have an AngularJS $watch alternative?
body: <p>I'm trying to migrate my current Angular.js project to Aurelia.js.
  I'm trying to do something like that:</p>
  
  <p><strong>report.js</strong></p>
  
  <pre><code>export class Report {
         list = [];
  
         //TODO
         listChanged(newList, oldList){
               enter code here
         }
  }
  </code></pre>
  
  <p><strong>report.html</strong></p>
  
  <pre><code>&lt;template&gt;
      &lt;require from="component"&gt;&lt;/require&gt;
      &lt;component list.bind="list"&gt;&lt;/component&gt;
  &lt;/template&gt;
  </code></pre>
  
  <p>So the question is: how to detect when is the list changed? </p>
  
  <p>In Angular.js I can do </p>
  
  <pre><code>$scope.$watchCollection('list', (newVal, oldVal)=&gt;{ my code });
  </code></pre>
  
  <p>Maybe Aurelia have something similar?</p>