code: function(ev) {
      this.requisition.setAssignment(this.assignment, ev.conversion.arg,
                                     { matchPadding: true }).then(function() {
        this.textChanged();
      }.bind(this));
  
      var isError = ev.conversion.message != null && ev.conversion.message !== '';
      this.focusManager.setError(isError);
    }
docs: Called by the onFieldChange event (via the terminal) on the current Field