UnboundLocalError at /Tag/HTC-Phones/ 分配前引用的局部变量'tag' - Django

Question

我收到以下错误：

UnboundLocalError at /Tag/HTC-Phones/
local variable 'tag' referenced before assignment
/home/pc/Desktop/django_stuff/blog_project/blog_app/views.py in tag_detail, line 86

models.py：

class Tag(models.Model):
    Tag_Name = models.CharField(max_length=100)
    slug = models.SlugField(unique=True,editable=True,max_length=200)

    def __str__(self):
        return self.Tag_Name

    def get_absolute_url(self):
        return reverse('tag_detail_url', kwargs={'slug':self.slug})

class Mobile(models.Model):
    name = models.CharField(max_length=100,default="")
    post_date = models.DateTimeField(auto_now_add=True, null=True, blank=True)
    tag = models.ManyToManyField('Tag',blank=True,related_name='posts')

views.py：

from .models import Tag

def tag_detail(request,slug):
    tag = Tag.objects.filter(manytomanyfield=tag)
    return render(request,'website_primary_html_pages/tag_detail.html',context={'tag':tag})

tag = Tag.objects.filter(manytomanyfield=tag) 中的视图错误

如何解决这个问题，谢谢

Answer 1

您可以通过以下方式获取给定标签的相关Mobiles：

from django.shortcuts import get_object_or_404, render
from .models import Tag, Mobile

def tag_detail(request,slug):
    tag = get_object_or_404(Tag, slug__iexact=slug)
    mobiles = Mobile.objects.filter(tag=tag)
    context = {
        'tag': tag,
        'mobiles': mobiles
    }
    return render(request, 'website_primary_html_pages/tag_detail.html', context)

在模板中你用：

{% for mobile in mobiles %}
    <!-- render the mobile -->
    {{ mobile.name }}
{% endfor %}

你也可以paginate [Django-doc] mobiles 对象：

from django.core.paginator import Paginator
from django.shortcuts import get_object_or_404, render
from .models import Tag, Mobile

def tag_detail(request,slug):
    tag = get_object_or_404(Tag, slug__iexact=slug)
    mobiles = Mobile.objects.filter(tag=tag)
    paginator = Paginator(mobiles, 25)  # ← 25 objects per page
    page_obj = paginator.get_page(request.GET.get('page'))
    context = {
        'tag': tag,
        'mobiles': mobiles,
        'page_obj': page_obj
    }
    return render(request, 'website_primary_html_pages/tag_detail.html', context)

然后你遍历page_obj:

{% for mobile in page_obj %}
    <!-- render the mobile -->
    {{ mobile.name }}
{% endfor %}

Paginating a ListView [Django-doc] 部分包含有关如何呈现指向上一页/下一页的链接的信息。