title: From my directive, how can I manually trigger a digest cycle on my parent scope?
body: <p>I have a directive that I would like to force render when a change is made to an underlying model programmatically. <code>$scope.$apply</code> is idiomatic. But I am unable to get the directive to render without clicking repeatedly on the UI (which presumably manually forces the digest).</p>
  
  <p>Can someone help me identify how to manually trigger the digest?</p>
  
  <p>Even <code>this.scope.$root.$apply()</code> has no effect. </p>
  
  <p>Grabbing hold of a parent DOM node and getting the associated scope, then calling <code>$apply</code> on that from the console, does work however.</p>
  
  <p>When using this DOM node approach in the code it does not work however. Why might this be?</p>