title: Angular2 PrimeNG Editing dirty flag
body: <p>I am using PrimeNG and have the table as editable, but how do I identify which rows were changed, as I don't see any kind of "ng-dirty" or other dirty flag set other than a _$visited flag which only shows that the cell was clicked on.  I want to be able to save all the table changes at once and also highlight the changed rows instead of saving as each cell is changed.  Sample column is as below:</p>
  
  <pre><code>&lt;p-dataTable [value]="parts"&gt;
  &lt;p-column field="partLength" header="Part Length" [editable]="true" &gt;
  </code></pre>
  
  <p>Thanks</p>