Question

Inside my view.py, I have two functions, one that processes input from a form and outputs a filtered list, and another that is supposed to export this list to CSV.

Here is the return of my first function:

return render_to_response('templateX.html',
{
 'queryset': queryset,
 'filter_form': filter_form,
 'validated': validated,
},
 context_instance = RequestContext(request)
 )

Here is the exporting function:

def export_to_csv(request):
    # get the response object, this can be used as a stream.
    response = HttpResponse(mimetype='text/csv')
    # force download.
    response['Content-Disposition'] = 'attachment;filename=export.csv'
    # the csv writer
    writer = csv.writer(response)
    qs = request.session['queryset']
    for cdr in qs:
        writer.writerow([cdr['calldate'], cdr['src'], cdr['dst'], ])
    return response   

I’m not sure how to get the queryset from my first function, which contains a list of the items I want in my CSV and use it in my export_to_csv function.
Or would the best way be combining these two functions and have the user click on a checkbox whether he/she wants to download a CSV file.
Any help would be appreciated.

Answer 1

I’d recommend combining these into one view function which takes an extra parameter:

def my_view(request, exportCSV):
    # ... Figure out `queryset` here ...

    if exportCSV:
        response = HttpResponse(mimetype='text/csv')
        response['Content-Disposition'] = 'attachment;filename=export.csv'
        writer = csv.writer(response)
        for cdr in queryset:
            writer.writerow([cdr['calldate'], cdr['src'], cdr['dst'], ])
        return response
    else:
        return render_to_response('templateX.html', {'queryset': queryset,
            'filter_form': filter_form, 'validated': validated},
            context_instance = RequestContext(request))

Then, in your urls.py, put something like this in your urlpatterns:

url(r'^form', 'my_view', {"exportCSV": False}, name="form"),
url(r'^csv', 'my_view', {"exportCSV": True}, name="export"),