how can i set the key 'blob-key' about BlobStore?

Question

I tried to use the jquery plugin "uploadify" to upload multiple files to My App in Google App-Engine, and then save them with blobstore, but it failed. I traced the code into get_uploads, it seems field.type_options is empty, and of course does not have 'blob-key'. Where does the key 'blob-key' come from?

the code like this:

def upload(request):
   for blob in blogstorehelper.get_uploads(request, 'Filedata'):
       file = File()
       file.blobref = blob
       file.save()
   return ……

but, blogstorehelper.get_uploads(request, 'Filedata') is always empty. In fact, the request has contained the uploaded file(I print the request). I debugged into the blogstorehelper.get_uploads, and found that field.type_options is empty. who can tell me why? thank you! here is the source about get_uploads: http://appengine-cookbook.appspot.com/recipe/blobstore-get_uploads-helper-function-for-django-request/?id=ahJhcHBlbmdpbmUtY29va2Jvb2tyjwELEgtSZWNpcGVJbmRleCI4YWhKaGNIQmxibWRwYm1VdFkyOXZhMkp2YjJ0eUZBc1NDRU5oZEdWbmIzSjVJZ1pFYW1GdVoyOE0MCxIGUmVjaXBlIjphaEpoY0hCbGJtZHBibVV0WTI5dmEySnZiMnR5RkFzU0NFTmhkR1ZuYjNKNUlnWkVhbUZ1WjI4TTIxDA

Answer 1

the code like this:
def upload(request):
   for blob in blogstorehelper.get_uploads(request, 'Filedata'):
       file = File()
       file.blobref = blob
       file.save()
   return ……

but, blogstorehelper.get_uploads(request, 'Filedata') is always empty. In fact, the request has contained the uploaded file(I print the request). I debugged into the blogstorehelper.get_uploads, and found that field.type_options is empty. who can tell me why? thank you! here is the source about get_uploads: http://appengine-cookbook.appspot.com/recipe/blobstore-get_uploads-helper-function-for-django-request/?id=ahJhcHBlbmdpbmUtY29va2Jvb2tyjwELEgtSZWNpcGVJbmRleCI4YWhKaGNIQmxibWRwYm1VdFkyOXZhMkp2YjJ0eUZBc1NDRU5oZEdWbmIzSjVJZ1pFYW1GdVoyOE0MCxIGUmVjaXBlIjphaEpoY0hCbGJtZHBibVV0WTI5dmEySnZiMnR5RkFzU0NFTmhkR1ZuYjNKNUlnWkVhbUZ1WjI4TTIxDA