cupertinoHelperBuilder<T> function
A function typically used for building a CupertinoFormRow helper widget.
Returns a Text widget when FastFormField.helperText is a String
otherwise null
.
Implementation
Text? cupertinoHelperBuilder<T>(FastFormFieldState<T> field) {
final FastFormField<T>(:helperText) = field.widget;
return helperText is String ? Text(helperText) : null;
}