Something like BodyPart

[huanghui1998hhh]

I have a branch implemented a feature that allow use @BodyPart to add a part parameter to request body. It like this:

  @POST('chat/send/msg')
  Future<SendMsgVO> sendMessage(
    @Body() SendMsgDTO dto, {
    @BodyPart(value: 'role_hash_id') required String roleHashId,
    @BodyPart(value: 'chat_model') String? aiModel,
  });

And it will generate this:

  @override
  Future<SendMsgVO> sendMessage(
    SendMsgDTO dto, {
    required String roleHashId,
    String? aiModel,
  }) async {
    final _extra = <String, dynamic>{};
    final queryParameters = <String, dynamic>{};
    queryParameters.removeWhere((k, v) => v == null);
    final _headers = <String, dynamic>{};
    final _data = <String, dynamic>{
      'role_hash_id': roleHashId,
      'chat_model': aiModel,
    };
    _data.addAll(dto.toJson());
    
    ......
  }

This avoids polluting the original model with additional fields or add new models.

By the way, it allows combining fields from multiple models as the request body by BodyPart.expand. If expands is true, when a model is passed in, its fields will be flattened to the same level as the Body.

Since my forked version is outdated and has diverged from the master branch, I'm currently encountering some issues while upgrading dependencies. If you think this feature make sense, I will reimplement it based on the current master branch and submit a PR. Or any other suggestions for this feature, please let me know.

[huanghui1998hhh]

@trevorwang Any suggestions for this feature?