minItems<T extends Iterable<Object?> > function
Creates a validator that fails when an Iterable collection has fewer than n items.
Returns message (or 'Must have at least $n items.' by default).
final tagsField = BloomTypedFormField<List<String>>(
initialValue: [],
validators: [minItems(1, 'Select at least one tag.')],
);
Implementation
String? Function(T) minItems<T extends Iterable<Object?>>(int n,
[String? message]) =>
(v) => v.length < n ? (message ?? 'Must have at least $n items.') : null;