title: swift insert row with animation effect
body: <p>In the first draft of my app, I filled my NSTableView with a static array.
  I had a NSButton, which inserts a new row with an animation effect like this:</p>
  
  <pre><code>tableView.beginUpdates()
  tableView.insertRows(at: IndexSet(integer: tableview.numberOfRows), withAnimation: .effectFade)
  tableView.endUpdates()
  </code></pre>
  
  <p>Short question at this point:
  Do I need the begin-/endUpdates() command?
  I see now difference if I use this code or not.</p>
  
  <p><strong>Primary Problem:</strong></p>
  
  <p>Now my second draft:</p>
  
  <p>Now I fetch my data for the TableView from Core Data.
  If I click on the NSButton (to insert a new row) I do something different: I create a new record, save it into core data, fetch all data again and reload my TableView.</p>
  
  <p>This works fine, but I can't use this line anymore in my second draft.</p>
  
  <pre><code>tableView.insertRows(at: IndexSet(integer: tableview.numberOfRows), withAnimation: .effectFade)
  </code></pre>
  
  <p>Anybody an idea how can I use this "beautiful" animation with core data again?</p>