required function

String? Function(String) required([
  1. String? message
])

Creates a validator that fails when a string value is empty or consists solely of whitespace.

Returns message (or 'This field is required.' by default) when invalid, and null when valid.

final nameField = BloomFormField(
  validators: [required('Full name is required.')],
);

Implementation

String? Function(String) required([String? message]) =>
    (v) => v.trim().isEmpty ? (message ?? 'This field is required.') : null;