Django download file not working

Question

I\'m trying to make a script for downloading the uploaded files, on the user\'s machine. The problem is that the download simply doesn\'t work (it either downloads me an emp

Answer 1

edited

I think that you need to extract path value from FileField object:

def download_course(request, id):
    course = Courses.objects.get(pk = id).course

    path = course.path # Get file path
    wrapper = FileWrapper( open( path, "r" ) )
    content_type = mimetypes.guess_type( path )[0]

    response = HttpResponse(wrapper, content_type = content_type)
    response['Content-Length'] = os.path.getsize( path ) # not FileField instance
    response['Content-Disposition'] = 'attachment; filename=%s/' % \ 
                                       smart_str( os.path.basename( path ) ) # same here

    return response

Why is that:

Let's say I have (well, I actually have) Model:

class DanePracodawcy( DaneAdresowe, DaneKontaktowe ):
    # other fields
    logo = ImageWithThumbnailsField( upload_to = 'upload/logos/',
                                  thumbnail = {'size': (180, 90)},
                                  blank = True )

ImageWithThumbnailsField is subclass of FileField, so it behaves the same way. Now, when I do SELECT:

mysql> select logo from accounts_danepracodawcy;
+-----------------------------+
| logo                        |
+-----------------------------+
| upload/logos/Lighthouse.jpg |
+-----------------------------+
1 row in set (0.00 sec)

it shows (relative to MEDIA_ROOT) path of stored file. But when I access logo Model attribute:

[D:projekty/pracus]|1> from accounts.models import DanePracodawcy
[D:projekty/pracus]|4> DanePracodawcy.objects.get().logo
                   <4> 
[D:projekty/pracus]|5> type( _ )
                   <5> 

I get instance of some object. If I try to pass that instance to os.path.getsize:

[D:projekty/pracus]|8> import os.path
[D:projekty/pracus]|9> os.path.getsize( DanePracodawcy.objects.get().logo )
---------------------------------------------------------------------------
TypeError                                 Traceback (most recent call last)

D:\projekty\pracus\ in ()

C:\Python26\lib\genericpath.pyc in getsize(filename)
     47 def getsize(filename):
     48     """Return the size of a file, reported by os.stat()."""
---> 49     return os.stat(filename).st_size
     50
     51

TypeError: coercing to Unicode: need string or buffer, ImageWithThumbnailsFieldFile found

I get TypeError, like you. So I need file path as string, which can be obtained with path attribute:

[D:projekty/pracus]|13> os.path.getsize(  DanePracodawcy.objects.get().logo.path )
                   <13> 561276L

Alternatively, I could get name attribute and os.path.join it with MEDIA_ROOT setting:

[D:projekty/pracus]|11> from django.conf import settings
[D:projekty/pracus]|12> os.path.getsize(  os.path.join( settings.MEDIA_ROOT, DanePracodawcy.objects.get().logo.name ) )
                   <12> 561276L

But that's unnecessary typing.

Last thing to note: because path is absolute path, I need to extract filename to pass it to Content-Disposition header:

[D:projekty/pracus]|16> DanePracodawcy.objects.get().logo.path
                   <16> u'd:\\projekty\\pracus\\site_media\\upload\\logos\\lighthouse.jpg'
[D:projekty/pracus]|17> os.path.basename( DanePracodawcy.objects.get().logo.path )
                   <17> u'lighthouse.jpg'