title: Create Download PDF File and store it into a Model
body: <p>I've created a PDF Creator with WeasyPrint and included the download function. Is it now possible to store that PDF File immediately into a Model-FileField (called Invoice)? How should this code look like?</p>
  
  <pre><code>def generate_pdf(request):
  # Rendered
  html_string = render_to_string('bills/pdf/invoice.html', context)
  html = HTML(string=html_string, base_url=request.build_absolute_uri())
  result = html.write_pdf(stylesheets=[CSS(settings.STATIC_ROOT +  '/css/bills.css')], presentational_hints=True);
  
  # Creating http response
  response = HttpResponse(content_type='application/pdf;')
  invoice_number = context['invoice_id']
  filename = "Invoice" + str(invoice_number) + ".pdf"
  response['Content-Disposition'] = 'inline; filename="{}"'.format(filename)
  pdf_file = HTML(string=html_string,
               base_url=settings.MEDIA_ROOT).write_pdf()
  
  new_bill = Invoice(invoice_no=billNumber, invoice_file=temp)
  new_bill.save()
  
  
  response['Content-Transfer-Encoding'] = 'binary'
  with tempfile.NamedTemporaryFile(delete=True) as output:
      output.write(result)
      output.flush()
      output = open(output.name, 'rb')
      response.write(output.read())
      download = request.GET.get("download")
      if download:
          content = "attachment; filename='%s'" %(filename)
      response['Content-Disposition'] = output
  return response
  </code></pre>