handlers.py 文件源码

def products_changed_handler(sender, **kwargs):
    """
        ?????????? ??????? ????????? ???-?? ??????? ?????????,
        ??????????? ??????????????? ? ?????????.

        ???????????? ??? ?????????? ????????? ??????? ? ?????? ?????????.
    """
    categories = kwargs.get('categories')
    if isinstance(categories, ShopCategory):
        # ????????? ?????????
        categories = ShopCategory.objects.filter(pk=categories.pk)
    elif isinstance(categories, (int, str)):
        # ?????? ??? ?????, ?????????? ID ?????????
        categories = ShopCategory.objects.filter(pk=categories)
    elif isinstance(categories, (list, tuple, set, ValuesListQuerySet)):
        # ?????? ????? ??? ?????, ?????????? ID ?????????
        categories = ShopCategory.objects.filter(pk__in=categories)
    elif isinstance(categories, QuerySet) and categories.model is ShopCategory:
        # QuerySet ?????????
        pass
    else:
        raise TypeError('Invalid categories for signal "products_changed"')

    with transaction.atomic():
        categories.update(
            product_count=RawSQL(
                '(SELECT COUNT(*) '
                'FROM shop_shopproduct AS ssp '
                'WHERE ssp.category_id = shop_shopcategory.id '
                'AND ssp.is_visible = TRUE)',
                ()
            )
        )
        categories.update(
            total_product_count=F('product_count')
        )

    categories_changed.send(ShopCategory, categories=categories)