def METHOD_NAME(self, request, queryset):
    count = queryset.count()
    filecategory_form = FileCategoryForm(request.POST)
    if filecategory_form.is_valid():
        for file in queryset:
            filecategory_form.update_file_cat_and_sub_cat(file)
    if count > 1:
        messages.success(request, _("Successfully updated Category/Sub Category of %(c)s files." % {'c':count}))
    elif count == 1:
        messages.success(request, _("Successfully updated Category/Sub Category of a file."))