Default values

For a non-nullable field, during de-serialization, one can request that a default value be assigned to the field if its value is null. The default value is obtained from getJserDefault method of Serializer. This method can be overloaded to configure default values of non-nullable fields.

class User {
  String name;
  int age;
}

@GenSerializer(nullableFields: false)
class UserSerializer extends Serializer<User> with _$UserSerializer {
  T getJserDefault<T>(String field) {
    switch(field) {
      case 'name': return 'Messi' as T;
      case 'age': return 30 as T;
      default: return null;
    }
  }
}

Note, how the below deserialization results in usage of default values for name and age fields.

UserSerializer.fromMap({}) // => Player(name: 'Messi', age: 30)