How to declare a list of allowed mime-types for a file (form data)?

[rmeissn]

I can easily declare:

class example(BaseModel):
    file: flask_openapi3.FileStorage

that generates a file upload form within e.g. swagger. Now I'd like to declare a list of allowed mime-types, that are checked by pydantic and are also used by the OS file-chooser to restrict shown files.
I wasn't able to find any information on how to do so, thus I'm seeking for help through this issue.

See https://swagger.io/docs/specification/v3_0/describing-request-body/file-upload/

I can easily add an additional field file_type: Literal["image/png"] = Field(default="image/png"), but this will only show an additional selection field, which does not influence the OSs file chooser or validation of the file within the FileStorage.

[luolingchun]

Unfortunately, file uploads are integrated into form(multipart/form-data) to support additional fields.

I also didn't find any evidence that the openapi support system restricts the display of files.