Stringify models in formdata

[konstantin-doncov]

I want to send my model and files using @MultiPart(). My Spring server has the next endpoint:

@Transactional
@PostMapping("/test")
public void test(@Valid @RequestPart(value = "MyModel") MyModel myModel, @RequestPart(value = "listOfFiles") List<MultipartFile> listOfFiles,  @RequestPart(value = "oneFile") MultipartFile oneFile)

My working Retrofit code in Java:

@Multipart
@POST("/test")
Call<Void> test(@Part("MyModel") MyModel myModel, @Part List<MultipartBody.Part> listOfFiles, @Part MultipartBody.Part oneFile);

But I can't do the same with the Retrofit.dart:

@MultiPart()
@POST("/test")
Future<void> test(@Part("MyModel") MyModel myModel, @Part() List<File> listOfFiles, @Part() File oneFile);

Generated file:

@override
test(myModel, listOfFiles, oneFile) async {
  ArgumentError.checkNotNull(myModel, 'myModel');
  ArgumentError.checkNotNull(listOfFiles, 'listOfFiles');
  ArgumentError.checkNotNull(oneFile, 'oneFile');
  const _extra = <String, dynamic>{};
  final queryParameters = <String, dynamic>{};
  final _data = FormData.fromMap(<String, dynamic>{
    'MyModel': myModel,
    'listOfFiles': listOfFiles,
    'oneFile': MultipartFile.fromFileSync(oneFile.path,
        filename: oneFile.path.split(Platform.pathSeparator).last)
  });
  await _dio.request<void>('/test',
      queryParameters: queryParameters,
      options: RequestOptions(
          method: 'POST',
          headers: <String, dynamic>{},
          extra: _extra,
          baseUrl: baseUrl),
      data: _data);
  return Future.value(null);
}

Even if I don't send files, like this:

@MultiPart()
@POST("/test")
Future<void> test(@Part("MyModel") MyModel myModel);

The problem is that I get this exception:

DioError [DioErrorType.RESPONSE]: Http status error [415]
"error" -> "Unsupported Media Type"
"message" -> "Content type 'application/octet-stream' not supported"

So, how can I send my model and my files to the specified endpoint?

[trevorwang]

Currently, only limited type can be supported. e.g. each property as parameter and single file

[trevorwang]

Will support your scenario in next release

[konstantin-doncov]

@trevorwang ok, but what workaround can I use for this scenario now?

[trevorwang]

This action that submit file with content is not recommended.
From my side I'd prefer to submit file in a separated request. And then submit all data with returned file URL in another one. You have to retry the request even only one filed was saved failed.

[konstantin-doncov]

@trevorwang thank you for the new release.

1. Unfortunately, I can’t use it yet:
   retrofit: ^1.2.1 returns:

Because project depends on retrofit ^1.2.1 which doesn't match any versions, version solving failed.

So, I tried to use git version:

  retrofit:
    git:
      url: git://github.com/trevorwang/retrofit.dart.git

It returns:

Could not find a file named "pubspec.yaml" in git://github.com/trevorwang/retrofit.dart.git 8bd0d86.

2. I saw this version adds support for multiple files, but can I send my class as a payload like this:
   @Part("MyModel") MyModel myModel?

[trevorwang]

It's retrofit_generator. You don't need to upgrade retrofit.

You can check the sample.dart to see more details.

[konstantin-doncov]

@trevorwang @Part("MyModel") Map<String, dynamic> myModel and @Part("MyModel") MyModel myModel with the new retrofit_generator give:

DioError [DioErrorType.RESPONSE]: Http status error [400]
"message" -> "Required request part 'MyModel' is not present"

[trevorwang]

Did you try with dio directly? I am not familiar with spring, may it needs some special config before you use formdata.

[konstantin-doncov]

@trevorwang no, I haven't tried dio. But I have already successfully used this code in Retrofit in Java:

@Multipart
@POST("/test")
Call<Void> test(@Part("MyModel") MyModel myModel);

with this Spring endpoint.

[trevorwang]

Currently, when you put a map to a FormData, dio will post

   "form": {
    "map[key1]":xxxx,
   "map[key2]:xxxxx 
}

instead of

"form": {
    "map": ''value to string"
}

There're some BREAKING changes both on annotation and generator package if I keep the behavior with dio. Please use a string value parameter as a workaround. (passing the MyModel.toString() )

I will provide a solution lately.

[trevorwang]

please upgrade your generator to 1.2.1+1

…

On Feb 11, 2020, at 11:09 AM, don-prog ***@***.***> wrote: @trevorwang <https://github.com/trevorwang> no, I haven't tried dio. But I have already successfully used this code in Retrofit in Java: @multipart @post("/test") Call<Void> ***@***.***("MyModel") MyModel myModel); with this Spring endpoint. — You are receiving this because you were mentioned. Reply to this email directly, view it on GitHub <#111?email_source=notifications&email_token=AAA5Y3SHUNHAIARIOJC7GLDRCIJIBA5CNFSM4KRVAUM2YY3PNVWWK3TUL52HS4DFVREXG43VMVBW63LNMVXHJKTDN5WW2ZLOORPWSZGOELLCYGI#issuecomment-584461337>, or unsubscribe <https://github.com/notifications/unsubscribe-auth/AAA5Y3XDXKP5LURQU45DW7TRCIJIBANCNFSM4KRVAUMQ>.

[konstantin-doncov]

@trevorwang I upgraded my retrofit_generator to ^1.2.1+1 and tried @Part("MyModel") Map<String, dynamic> myModel with myModel.toJson() and just @Part("MyModel") MyModel myModel.
This generated key="MyModel[myField]" and value="my string value" in the data.fields[0].
And I still have

"Required request part 'MyModel' is not present"

[trevorwang]

MyModel.toString()

[konstantin-doncov]

@trevorwang unfortunately, I don't fully understand you. Do you want me to use the non-overridden toString() with @Part("MyModel") String myModel? If so, then it's does not take into account the fields, and I get an error 415 again. Also, I can override it, but what's the point to use Retrofit?

[trevorwang]

Have a try toJason().toString() to JsonEncode as a workaround.

The feature will be supported in the future release. I am thinking how to figure out it better.

[konstantin-doncov]

@trevorwang unfortunately, I still have 415 error - please check this, I left here information about requests.