validate method

  1. @override
String? validate(
  1. String? value, {
  2. BuildContext? context,
})
override

Validates the given value. Returns an error message String if validation fails, otherwise returns `null].

The context can optionally be used by rules needing access to localization, etc. This context is provided by the FieldValidator when getValidator is called.

Implementation

@override
String? validate(String? value, {BuildContext? context}) =>
    (value ?? '').trim().isEmpty ? message : null;