utils.py 文件源码

def channel_new_messages_annotation(user):
    """
    Queryset needs to annotated with channel_last_read for this to work
    :param user:
    :return:
    """
    return Sum(
        Case(
            When(
                ~Q(action_targets__actor_object_id=user.id) &
                Q(action_targets__gt=F('channel_last_read')) &
                Q(action_targets__verb__in=[verbs.SEND, verbs.UPLOAD]),
                then=1
            ),
            default=0,
            output_field=IntegerField()
        )
    )