UriValidator class abstract interface

An abstract validator for URI/URL validation.

This provides a contract for validating URIs and returning appropriate error messages when validation fails. Implement this to create custom URI validation logic.

Example Usage:

class HttpUriValidator implements UriValidator {
  @override
  bool isValid(Uri uri) => uri.scheme == 'http' || uri.scheme == 'https';

  @override
  String get errorMessage => 'Must be a valid HTTP/HTTPS URL';
}

void main() {
  final validator = HttpUriValidator();
  final uri = Uri.parse('https://example.com');
  
  if (!validator.isValid(uri)) {
    print(validator.errorMessage);
  }
}