Array Controller

    add_item: function() {
      // create new LedgerEntry and add it to the list
      var that = this;
      var ledger_entry = EccapCalc.store.createRecord(EccapCalc.LedgerEntry, {
        ledger: that.ledger,
      });

      // select new LedgerEntry in UI
      this.selectObject(ledger_entry); 

      // activate inline editor once UI can repaint
      this.invokeLater(function() {
        var contentIndex = this.indexOf(ledger_entry);
        var view = EccapCalc.mainPage.getPath(path_to_view + '.description.contentView');
        var listItem = view.itemViewForContentIndex(contentIndex);
        listItem.beginEditing();
      });
      return YES ;
    },