3

我的问题是 if 条件。

我想要这样的东西,但不知道该怎么做。

{% if restaurant.is_favorite_of(user) %}
     <img src="{{MEDIA_URL}}images/favorite_on.png" alt="This restaurant is one of your favorite (Click to undo)" />
{% else %}
     <img src="{{MEDIA_URL}}images/favorite_off.png" alt="This restaurant is not one of your favorite (Click to add to your favorite)" />
{% endif %}

在收藏夹管理器中,我创建了:

def is_favorite(self, user, content_object):
    """
    This method returns :
       - True if content_object is favorite of user
       - False if not
    >>> user = User.objects.get(username="alice")
    >>> fav_user = User.objects.get(username="bob")
    >>> fav1 = Favorite.create_favorite(user, fav_user)
    >>> Favorite.objects.is_favorite(user, fav_user)
    True
    >>> Favorite.objects.is_favorite(user, user)
    False
    >>> Favorite.objects.all().delete()

    Above if we test if bob is favorite of alice it is true.
    But alice is not favorite of alice.
    """
    ct = ContentType.objects.get_for_model(type(content_object))
    try:
        self.filter(user=user).filter(content_type = ct).get(object_id = content_object.id)
        return True
    except Favorite.DoesNotExist:
        return False

因为在 Django 模板中没有办法做到这一点,所以我可以做一个这样的模板标签:

{% is_favorite user resto %}
     <img src="{{MEDIA_URL}}images/favorite_on.png" alt="This restaurant is one of your favorite (Click to undo)" />
{% else %}
     <img src="{{MEDIA_URL}}images/favorite_off.png" alt="This restaurant is not one of your favorite (Click to add to your favorite)" />
{% endif %}

但是怎么做呢?你有更好的主意吗?

4

3 回答 3

11

最简单的方法是创建一个过滤器。

@register.filter
def is_favourite_of(object, user):
    return Favourite.objects.is_favourite(user, object)

并在模板中:

{% if restaurant|is_favourite_of:user %}
于 2009-10-10T07:35:06.807 回答
2

也许我可以使用包含标签

创建一个这样的标签:

{% show_favorite_img user restaurant %}

模板标签/user_extra.py :

@register.inclusion_tag('users/favorites.html')
def show_favorite_img(user, restaurant):
    return {'is_favorite': Favorite.objects.is_favorite(user, restaurant)}
于 2009-10-10T02:09:08.657 回答
0

当所有其他方法都失败时,您可以使用 {% expr 不管 %} 标记来计算一个值并将其粘贴到您可以在模板中使用的变量中。我不会让设计师知道这件事,但有时它是唯一有效的方法,而不是站在你的头上……嗯,你知道的。

http://www.djangosnippets.org/snippets/9/

于 2009-10-11T01:01:17.867 回答