validate method
Implementation
Future<void> validate(
dynamic rules, [
Map<String, String> messages = const <String, String>{},
]) async {
assert(rules is Map<String, String> || rules is List<Validation>,
'Rules must be either Map<String, String> or List<Validation>.');
TemplateEngine().sessionErrors.clear();
if (rules is Map<String, String>) {
await _validate(rules, messages);
} else {
_validateChain(rules as List<Validation>);
}
}