validator property

FormFieldValidator<String>? validator
final

validators for this field. Defaults to _NumberInputWithIncrementDecrementState._defaultValidator validator based on the values of min and max field. Note: These values default to 0 and double.infinity respectively.

String _minMaxValidator(String value) {
   return num.parse(value) < widget.min || num.parse(value) > widget.max
       ? 'Value should be between ${widget.min} and ${widget.max}'
       : null;
 }

Implementation

final FormFieldValidator<String>? validator;