title: how to emit events from a factory
body: <p>How can I emit events from a factory or service. I am unable to inject $scope into the factory, thus unable to emit events.</p>
  
  <p>I get the following error -  <code>Unknown provider: $scopeProvider &lt;- $scope</code> </p>
  
  <p>Thanks,
  Murtaza</p>