django rest framework return file

Question

I have the following view in my views.py -

class FilterView(generics.ListAPIView):
    model = cdx_composites_csv

    def get(self, request, format=None):
        vendor = self.request.GET.get('vendor')
        filename = self.request.GET.get('filename')
        tablename = filename.replace(".","_")
        model = get_model(vendor, tablename)
        filedate = self.request.GET.get('filedate')        
        snippets = model.objects.using('markitdb').filter(Date__contains=filedate)
        serializer = cdx_compositesSerializer(snippets, many=True)
        if format == 'raw':
            zip_file = open('C:\temp\core\files\CDX_COMPOSITES_20140626.zip', 'rb')
            response = HttpResponse(zip_file, content_type='application/force-download')
            response['Content-Disposition'] = 'attachment; filename="%s"' % 'CDX_COMPOSITES_20140626.zip'
            return response

        else:
            return Response(serializer.data)

It works great for xml, json, csv but when I try to use raw it's not returning the file instead it's giving ""detail": "Not found"" why is this happening?

The URL I'm hitting is as follows -

json example that works -

http://dt-rpittom:8000/testfilter/?vendor=markit&filename=cdx_composites.csv&filedate=2014-06-26&format=json

This should return a zip file for download.

http://dt-rpittom:8000/testfilter/?vendor=markit&filename=cdx_composites.csv&filedate=2014-06-26&format=raw

Answer 1

I don't know why I had to do this - may be something internal to Django Rest Framework that doesn't allow putting custom methods onto format?

I simply changed it to the following -

if fileformat == 'raw':
    zip_file = open('C:\temp\core\files\CDX_COMPOSITES_20140626.zip', 'rb')
    response = HttpResponse(FileWrapper(zip_file), content_type='application/zip')
    response['Content-Disposition'] = 'attachment; filename="%s"' % 'CDX_COMPOSITES_20140626.zip'
    return response

Then in my URL just hit with the new value and it works fine. I'd love to know why I can't use format though to serve a file.

Answer 2

Try using FileWrapper:

from django.core.servers.basehttp import FileWrapper

...

if format == 'raw':
    zip_file = open('C:\temp\core\files\CDX_COMPOSITES_20140626.zip', 'rb')
    response = HttpResponse(FileWrapper(zip_file), content_type='application/zip')
    response['Content-Disposition'] = 'attachment; filename="%s"' % 'CDX_COMPOSITES_20140626.zip'
    return response
...

Also, I would use application/zip instead of application/force-download.