Django 模板中不可用的上下文属性

Question

我正在尝试在 Django 的模板中显示特定属性。 我相信我已经在上下文中传递了正确的查询集，但由于某种原因，我只能访问 id 属性，而不是我需要的 title 属性。

视图.py：

@login_required
def watchlist_view(request):
    listings = models.WatchedListing.objects.filter(owner = request.user)
    return render(request, "auctions/watchlist.html", {"listings": listings})

@login_required
def add_to_watchlist(request, listing_id):
    listing = models.Listing.objects.get(pk=listing_id)
    user = request.user
    currently_watched = models.WatchedListing.objects.filter(owner = request.user)
    if listing in currently_watched.all():
        messages.error(request, "This item is already on your watchlist.")
        return redirect(reverse('listing', args=[listing.pk]))
    else:
        watchlist = WatchedListing()
        watchlist.owner = user
        watchlist.watched_listing = listing
        watchlist.save()
        messages.success(request, "Added to your watchlist!")
        return redirect(reverse('listing', args=[listing.pk]))

模型.py：

class Listing(models.Model):
    title = models.CharField(max_length=64)
    description = models.TextField()
    start_bid = models.ForeignKey(Bid, on_delete=models.CASCADE, related_name="start_bid")
    image_url = models.TextField(null=True)
    category = models.CharField(max_length=64, null=True)
    current_bid = models.ForeignKey(Bid, on_delete=models.CASCADE, related_name="current_bid")
    is_active = models.BooleanField()
    owner = models.ForeignKey(User, on_delete=models.CASCADE)
    num_bids = models.IntegerField()
    created_at = models.DateTimeField(auto_now_add=True)

class WatchedListing(models.Model):
    watched_listing = models.ForeignKey(Listing, on_delete=models.CASCADE, related_name='watched_listings', blank=True, null=True)
    owner = models.ForeignKey(User, on_delete=models.CASCADE, related_name ='watchlist_owner')

监视列表.html：

{% extends "auctions/layout.html" %}

{% block title %} Watchlist {% endblock %}

{% block body %}

    {% if messages %}
        {% for message in messages %}
            <strong style="color: red">{{ message }}</strong>
        {% endfor %}
    {% endif %}

    {% if listings is not None %}
        <ul>
        {% for listing in listings %}
            <a href = "{% url 'listing' listing_id=listing.id %}">
                <li>{{ listing.title }}</li>
            </a>
        {% endfor %}
        </ul>
    {% else %}
        No watched listings yet.
    {% endif %}
{% endblock %}

在模板中有listing.title 的地方，我只是得到空白，但是ul 项目符号列表项显示了一个指向适当列表的链接。 但是，如果我更改为 listing.id，id 属性将显示出来。 我做错了什么来显示列表的标题？

Answer 1

您正在模板中获取WatchedListing的对象。 因此，要在那里获得标题，您需要通过ForeignKey字段将其引用为

<li>{{ listing.watched_listing.title }}</li>