required static method

String? required(
  1. String? value, {
  2. String? message,
})

Validates that the value is not empty

Example:

Validators.required(value);
Validators.required(value, message: 'Custom error message');

Implementation

static String? required(String? value, {String? message}) {
  if (value == null || value.trim().isEmpty) {
    return message ?? 'This field is required';
  }
  return null;
}