'Exports the selected rows using file_format.'

def export_admin_action(self, request, queryset):

    export_format = request.POST.get('file_format')
    if (not export_format):
        messages.warning(request, _('You    must    select    an    export    format.'))
    else:
        formats = self.get_export_formats()
        file_format = formats[int(export_format)]()
        export_data = self.get_export_data(file_format, queryset, request=request)
        content_type = file_format.get_content_type()
        try:
            response = HttpResponse(export_data, content_type=content_type)
        except TypeError:
            response = HttpResponse(export_data, mimetype=content_type)
        response['Content-Disposition'] = ('attachment;    filename=%s' % (self.get_export_filename(file_format),))
        return response
