FileUploadParser doesn't offer a file picker in the browsable API.

[jcoombes]

Problem: The browsable API doesn't interact well with the FileUploadParser.
Filling in the content field with the body of a CSV file doesn't help.

The view in question.

    @extend_schema(
        description="Import project structure from JIRA-compatible CSV",
        request={
            "multipart/form-data": {
                "type": "object",
                "properties": {
                    "file": {"type": "string", "format": "binary"},
                },
            },
        },
        responses={
            201: OpenApiResponse(
                description="Import successful with project data and URL",
                response=ProjectSerializer,
            ),
            400: OpenApiResponse(description="Bad request - invalid file or format"),
        },
    )
    @action(
        detail=False,
        name="import-csv",
        parser_classes=[FileUploadParser],
        renderer_classes=[JSONRenderer, BrowsableAPIRenderer],
        serializer_class=CsvSerializer,
        methods=["post"],
    )
    def import_csv(self, request: Request) -> Response:
        """Import project structure from JIRA-compatible CSV."""
        if "file" not in request.FILES:
            return Response(
                {"error": "No file uploaded"},
                status=status.HTTP_400_BAD_REQUEST,
            )

        csv_file = request.FILES["file"]
        if not csv_file.name.endswith(".csv"):
            return Response(
                {"error": "File must be a CSV"},
                status=status.HTTP_400_BAD_REQUEST,
            )

        try:
            assert isinstance(request.user, User)
            decoded_file = io.StringIO(csv_file.read().decode("utf-8"))
            (project, last_modified) = csv_io.import_jira(decoded_file, request.user)

            serializer = self.get_serializer(project)
            return Response(
                serializer.data,
                status=status.HTTP_201_CREATED,
            )

        except (UnicodeDecodeError, csv.Error) as e:
            return Response(
                {"error": f"Invalid CSV format: {e!s}"},
                status=status.HTTP_400_BAD_REQUEST,
            )

[jcoombes]

Adding a serializer includes the file picker which solves for my use case; this might just be a documentation issue. The documentation does not mention the required serializer anywhere.
https://www.django-rest-framework.org/api-guide/parsers/#fileuploadparser

    @extend_schema(
        description="Import project structure from JIRA-compatible CSV",
        request={
            "multipart/form-data": {
                "type": "object",
                "properties": {
                    "file": {"type": "string", "format": "binary"},
                },
            },
        },
        responses={
            201: OpenApiResponse(
                description="Import successful with project data and URL",
                response=ProjectSerializer,
            ),
            400: OpenApiResponse(description="Bad request - invalid file or format"),
        },
    )
    @action(
        detail=False,
        name="import-csv",
        serializer_class=CsvImportSerializer,
        methods=["post"],
    )
    def import_csv(self, request: Request) -> Response:
        """Import project structure from JIRA-compatible CSV."""
        if "file" not in request.FILES:
            return Response(
                {"error": "No file uploaded"},
                status=status.HTTP_400_BAD_REQUEST,
            )

        csv_file = request.FILES["file"]
        if not csv_file.name.endswith(".csv"):
            return Response(
                {"error": "File must be a CSV"},
                status=status.HTTP_400_BAD_REQUEST,
            )

        try:
            assert isinstance(request.user, User)
            decoded_file = io.StringIO(csv_file.read().decode("utf-8"))
            (project, last_modified) = csv_io.import_jira(decoded_file, request.user)

            output_serializer = ProjectSerializer(project, context={"request": request})
            return Response(
                output_serializer.data,
                status=status.HTTP_201_CREATED,
            )

        except (UnicodeDecodeError, csv.Error) as e:
            return Response(
                {"error": f"Invalid CSV format: {e!s}"},
                status=status.HTTP_400_BAD_REQUEST,
            )

[browniebroke]

The documentation does not mention the required serializer anywhere.
django-rest-framework.org/api-guide/parsers#fileuploadparser

That documentation page focuses purely on file uploads, especially the FileUploadParser class. It tries to provide a minimal example that works in the case of a programmatic request, ignoring the browsable API. introducing a serializer would be distracting the point of the section IMO.

We could however add a note at the end of the section to make this limitation clearer and point towards the solution (serializer with a FileField). Another potential page that may be suitable is the one about the browsable API, we could add a section that it infers form fields types from serializers and might be wrong if you don't use a serializer of if the serializer resolution is too dynamic...

PS: what was your original CsvSerializer?