Retrieve from Gridfs storage

[Anthony Eshleman]

Ive gone ahead followed to structure for sending the files to gridfs storage on mongodb. I can't find a procedure for retrieving said files again and downloading them. Has anyone encountered this before and know how to solve this?

[Dirk Holzhüter]

I am currently having exactly the same issue! Does anyone has a solution? How do I return a file saved to the database using djongo/gridfs???

After sending the file to the db, everything is properly generated.

My model (just the auto generated id and the FileField) is saved in the collection "myModel".  I get a collection of "myfiles.files" and myfiles.chunks.

my django model looks like:

grid_fs_storage = GridFSStorage(collection='myfiles', base_url=''.join([settings.BASE_URL, 'myfiles/'])) 

class myModel(models.Model):

    myfile = models.FileField(storage=grid_fs_storage)

    class Meta:

        db_table = 'myModel'

I use drf-spectacular with multipart-parser to upload the file and get the following entry in the database:

myModel collection:   

 { "_id": {"$oid": "62325e25e9c2c70bf38c8842"}, "id": 1, "myfile": "testfile.txt" }

myfiles.files collection:

{ "_id": { "$oid": "62325e25e9c2c70bf38c8840" },
    "filename": "testfile.txt",

    "contentType": "text/plain",
    "md5": "23ab190c3786a60d569795b473e34683",
    "chunkSize": 261120,
    "length": { "$numberLong": "90" },
    "uploadDate": { "$date": "2022-03-16T22:01:09.071Z"}
}

my endpoint returns on the post request:

{ "id": 1, "myfile": "http://localhost:8082/myfiles/62325e25e9c2c70bf38c8840"},

my view looks like:

class FileView(ListCreateAPIView):

    parser_classes = ( MultiPartParser,)

    serializer_class = myModelSerializer

    queryset = myModel.objects.all()

class myfiles(ListAPIView):

parser_classes = ( MultiPartParser,)

    serializer_class = myModelSerializer

    queryset = myModel.objects.all()

my urls.py looks like

... urlpatterns=[

re_path(r'^api/teststandards/file', api.FileView.as_view(), name='teststandard-file'),

    re_path(r'^myfiles', api.myfiles.as_view(), name='get-file'),

] I don't know how my view or the serializer should look like to return the file again?

How do I retrieve the file from the database with gridfs?

Any help is appreaciated. A small example to follow would be great!!!

regards

[Dirk Holzhüter]

Finally managed to get it to work...

This is how my views.py looks like:

#for upload

class FileView(ListCreateAPIView):

    parser_classes = ( MultiPartParser,)

    serializer_class = TestStandardFileSerializer

    queryset = TestStandardFile.objects.all()

# for download

class myfiles(RetrieveAPIView):

    parser_classes = ( MultiPartParser,)

    serializer_class = TestStandardFileSerializer

    queryset = TestStandardFile.objects.all()

   

    def retrieve(self, request, *args, **kwargs):

        obj = self.get_object()        

        response = HttpResponse(obj.myfile, content_type='application/octet-stream')

        response['Content-Disposition'] = 'attachment; filename=%s' % obj.myfile

        return response

...myfile is the name of the FileField