nullable function

IValidator nullable(
  1. IValidator validator
)

If the field is not present (null) it will be considered valid If you want to allow empty strings as valid, use optional instead

Example

final isValid = nullable(isString()).validate(null);  // true
final isValid = nullable(isString()).validate('');    // true
final isValid = nullable(isString()).validate(false); // false

// It works a bit differently on maps:

final validListField = eskema({
   'nullable': nullable(isString()),
});

validListField.isValid({'nullable': 'test'}); // true
validListField.isValid({'nullable': ''});     // true
validListField.isValid({'nullable': null});   // true

// If the field does not exists on the map, it's considered invalid.
// You can use the `optional` validator to allow missing fields.
validListField.isValid({});                   // false

Implementation

IValidator nullable(IValidator validator) => validator.nullable();