title: angular - stop two way binding or local value
body: <p>I would like to NOT bind javascript local value to $scope function automatically, but angular did. </p>
  
  <p>javascript code</p>
  
  <pre><code>    var startat = true;
      $scope.chagneStart = function() { startat = !startat}
      $scope.isStart = function() { return angular.copy( startat); }
  </code></pre>
  
  <p>html code</p>
  
  <pre><code>&lt;checkbox ng-click="chagneStartAt()"&gt;
  &lt;tr ng-show="isStartAt()"&gt; ... &lt;/tr&gt;
  </code></pre>
  
  <p>When I cliked checkbox, tr tag would be show or not depend on <em>start value</em>. I want to NOT change tr tag until call some other function, like applyOption().</p>