serialize method

@override Object? serialize(DartType targetType, String expression, TypeHelperContextWithConfig context)

Returns Dart code that serializes an expression representing a Dart object of type targetType.

If targetType is not supported, returns null.

Let's say you want to serialize a class Foo as just its id property of type int.

Treating expression as a opaque Dart expression, the serialize implementation could be a simple as:

String serialize(DartType targetType, String expression) =>
  "$expression.id";
```.

Implementation

@override
Object? serialize(
  DartType targetType,
  String expression,
  TypeHelperContextWithConfig context,
) {
  final converter = _typeConverter(targetType, context);

  if (converter == null) {
    return null;
  }

  if (!converter.fieldType.isNullableType && targetType.isNullableType) {
    const converterToJsonName = r'_$JsonConverterToJson';
    context.addMember('''
Json? $converterToJsonName<Json, Value>(
Value? value,
Json? Function(Value value) toJson,
) => ${ifNullOrElse('value', 'null', 'toJson(value)')};
''');

    return _nullableJsonConverterLambdaResult(
      converter,
      name: converterToJsonName,
      targetType: targetType,
      expression: expression,
      callback: '${converter.accessString}.toJson',
    );
  }

  return LambdaResult(expression, '${converter.accessString}.toJson');
}