title: Correct way to access a function in a scope
body: <p>I'm using user contributed modules that I am trying not to edit so that upgrades are nice and easy. </p>
  
  <p>I'm attempting to allow a user to browse to a CSV File on the local filesystem, parse it and display it in a dynamic table.  To do this I'm utilizing <code>PapaParse</code>, <code>ui.grid</code> and <code>angularFileUpload</code>. </p>
  
  <p>The problem I'm running into is that they all work at different levels at the hierarchy. </p>
  
  <p>angularFileUpload is nice an easy - it calls a function in my controller (using controllerAs syntax). That function then runs a PapaParse function to convert the CSV file to a JSON Object (all working so far). </p>
  
  <p>The problem I have is that <code>ui.grid</code> works on the $scope object since it's a attribute directive and doesn't support watchers to monitor for changes to a variable (you have to call a function on data update to re-bind the data). </p>
  
  <p>So the question is, from within my controller whats the <strong>correct/recommended</strong> way to communicate with an external directive without editing the directive to listen to messages. </p>