Can't use FromFiles and FromForm in same request

[nico-vromans]

For some reason, I can't seem to be able to perform both a multi-file upload with additional data on the same form.

Specs:

1. Python 3.10.4 (inside virtual environment)
2. blacksheep 1.2.5
3. Ubuntu 20.04

Here is my html code (simplified):

<form action='/upload_files_with_additional_data' method="post" enctype='multipart/form-data'>
    <input type="file" name="files" multiple>
    
    <label for="checkbox1" class="checkbox">Checkbox 1</label>
    <input type="checkbox" name="checkbox1">

    <label for="checkbox2" class="checkbox">Checkbox 2</label>
    <input type="checkbox" name="checkbox2">

    <label for="textfield">Text field</label>
    <input type="text" id="textfield" name="textfield">

    <input type="submit" value="Submit">
</form>

Here's what I've tried (but didn't work) and what I expect would work:

@post('/upload_files_with_additional_data')
async def upload_files_with_additional_data(self, files: FromFiles, form_data: FromForm):
for file in Files:
    # do something with each file

# do something with additional form data

I've also tried using FromForm[FormData] with the following FormData:

    class FormData:
        checkbox1: bool
        checkbo2: bool
        files: list  # also tried with type hint FromFIles (and without setting files alltogether

        # def __init__(self, checkbox1: str, checkbox2: str, files):  # also tried with files: FromFiles and without entire __init__ (but that didn't work at all)
            # self.checkbox1 = bool(checkbox1)
            # self.checkbox2 = bool(checkbox2)
            # self.files = files  # also tried with FromFiles(files)

Either I can upload files, without sending additional form data (using only files: FromFiles), or I can use the form data without the files (using only form: FromForm). Combining the two doesn't work.
When using async def upload_files_with_additional_data(self, request: Request): I can get also get the form data from there using form = await request.form(), but that only works for additional data, not the files. When I try to upload files I get:

form = await request.form()
  File "blacksheep/messages.pyx", line 172, in form
  File "blacksheep/contents.pyx", line 163, in blacksheep.contents.multiparts_to_dictionary
AttributeError: 'bytes' object has no attribute 'append'

I've also tried using async def upload_files_with_additional_data(self, bytes: FromBytes): which does seem to contain all the data, but as bytes, and I've tried a few ways to convert these to what I want, but no success there either.

Is there a way of uploading both multiple files, alongside other form data (I'm fairly confident there is, but I just haven't figured it out)? If so: how should this be achieved?

[RobertoPrevato]

Hi @nico-vromans!
Thank You for submitting this issue. I just verified this is a bug in the FromForm binder, the good news is that you can still use the explicit method to read the multipart data, which works:

    @post("/upload_files_with_additional_data")
    async def upload(self, request) -> Response:
        data = await request.multipart()
        print(data)
        return self.text("OK")

This returns a list of parts from the multi part request, with files and input. It's a lower level code API, though, closer to the shape of the message sent by browsers.

I will fix this bug as soon as possible, I think I already know what needs to be changed.
Right now it's late evening here, I'll look more into this in the weekend.

[nico-vromans]

@RobertoPrevato, thanks for the quick reply. I've tested this "workaround" myself and it works beautifully. 👍🏻

[RobertoPrevato]

I'm glad I could help. 🎉 These days I am working on a plugin for MkDocs to generate automatically human readable documentation from OpenAPI Documentation, so I have limited time for the web framework, but a fix will come soon.

[nico-vromans]

@RobertoPrevato, I'm in no rush and I fully understand having other priorities. Take your time. Good luck with MkDocs, sounds interesting 😉

[nico-vromans]

@RobertoPrevato, awesome, thank you 👍🏻 🥳

[RobertoPrevato]

@nico-vromans thank you for reporting this bug! 🎉 I'm still looking into a couple of things, then I'll publish a new version to PyPi with this fix. I have everything automated so I can release at any time to PyPi without issues.