使用外键数据对 Django 视图进行分页

Question

我正在尝试构建一个简单的 Django 画廊，允许将照片添加到相册中。到目前为止一切正常（上传照片、添加到相册、对所有照片列表进行分页、照片详细信息/显示页面等），直到我尝试显示“相册”页面。我可以让页面呈现相册和所有相关照片，但如果我尝试对相册进行分页，事情就会变得很奇怪。

这是我的模型：

# models.py

class Albums(models.Model):
    id = models.AutoField(primary_key=True, unique=True)
    name = models.CharField(max_length=500)
    slug = models.SlugField(max_length=500, unique=True)
    description = models.TextField(blank=True, null=True)

    def __str__(self):
        return self.name

    def save(self, *args, **kwargs):
        if not self.slug:
            self.slug = slugify(self.name)
        return super().save(*args, **kwargs)


class Photos(models.Model):    
    id = models.AutoField(primary_key=True, unique=True)
    album = models.ForeignKey(
        Albums, on_delete=models.SET_NULL, null=True, blank=True, verbose_name="Album"
    )
    photo = models.ImageField(upload_to="photos/")
    slug = models.CharField(max_length=16, null=False, editable=False) # I know I'm not using a SlugField here; that's on purpose
    title = models.CharField(max_length=500)
    description = models.TextField(blank=True, null=True)
    upload_date = models.DateTimeField(
        default=timezone.now, verbose_name="Date uploaded"
    )
    
    def __str__(self):
        return self.title

    def save(self, *args, **kwargs):
        [...] # stuff to get the image's EXIF data and use that to set the slug
        self.slug = str(datetime.strftime(img_date, "%Y%m%d%H%M%S"))
        [...] # plus a bunch of other stuff that happens on save, not important here
        super(Photos, self).save()

    def delete(self, *args, **kwargs):
        [...] # a bunch of stuff that happens on delete, not important here
        super(Photos, self).delete()

还有让我痛苦的观点：

# views.py

class PhotoAlbum(DetailView):
    context_object_name = "album"
    model = Albums
    slug_field = "slug"
    template_name = "page.html"

    def get_photos(self, **kwargs):
        # get the integer id of the album
        a = Albums.objects.filter(slug=self.kwargs["slug"])
        a_id = a.values()[0]["id"]
        # get the list go photos in that album
        photos = Photos.objects.all().order_by("-capture_date").filter(album_id=a_id)
        return photos

    def get_context_data(self, **kwargs):
        context = super(PhotoAlbum, self).get_context_data(**kwargs)
        context["photos"] = self.get_photos()
        return context

这些在基本模板中工作...

# album.html
<h2>{{ album.name }}</h2>
<p>{{ album.description }}</p>
<ul>
    {% for photo in photos %}
        <li><a href="{% url 'photo_detail' photo.slug %}">{{ photo.title }}</a></li>
    {% endfor %}
</ul>

...但是如果我尝试通过更改对照片进行分页...

photos = Photos.objects.all().order_by("-capture_date").filter(album_id=a_id)

...到...

photos = Paginator(Photos.objects.all().order_by("-capture_date").filter(album_id=a_id), 10)

...我什么也得不到。

在四处搜索时，我看到的几乎所有与分页有关的问题都是针对 DRF 的，所以在这里碰壁了。我在显示照片与相册的关系时遇到了各种麻烦（get_photos() 函数），所以我猜测我的部分问题在于。有关如何使其正常工作的任何建议？

Answer 1

Paginator 会给你一个分页器对象，而不是你正在分页的对象。要获取对象，首先需要指定页面，例如：

paginator = Paginator(Photos.objects.all().order_by("-capture_date").filter(album_id=a_id), 10)
photos = paginator.page(1)

photos 此处将包含 Photos 第 1 页上的对象。

Answer 2

基于Brian Destura 的comment，我返回并使用ListView 重新开始，在re-reading the Django docs 和一些混乱之后，我的观点得出了这个解决方案，基于一点测试，对我有用：

class AlbumDetail(ListView):
    context_object_name = "photos"
    template_name = "page.html"
    paginate_by = 6

    def get_queryset(self):
        a = Albums.objects.filter(slug=self.kwargs["slug"])
        a_id = a.values()[0]["id"]
        self.albums = get_object_or_404(Albums, slug=self.kwargs["slug"])
        return Photos.objects.filter(album_id=a_id).order_by("-capture_date")

    def get_context_data(self, **kwargs):
        context = super(AlbumDetail, self).get_context_data(**kwargs)
        context["album"] = self.albums
        return context

Answer 3

viwes.py

class PhotoAlbum(ListView):
    context_object_name = "album"
    model = Albums
    slug_field = "slug"
    template_name = "page.html"
    paginate_by = 5

page.html

这是分页逻辑

{%if is_paginated %}

         {%if page_obj.has_previous %}
          <a style="margin-left: 20px; padding: 10px 20px;" class=" btn btn-primary" href="?page={{page_obj.previous_page_number}}"> ?{{page_obj.num_pages}} previous</a>
          
         {% endif %}

         {%if page_obj.has_next %}
         {% if page_obj.num_pages == 1 %}
             <a style="margin-left: 930px; padding: 10px 28px;" class=" btn btn-primary" href="?page={{page_obj.next_page_number}}">next ?</a>
          {% else %}
            <a style="margin-left: 880px; padding: 10px 28px;" class=" btn btn-primary" href="?page={{page_obj.next_page_number}}">next ?</a>
           {% endif %}
         {% endif %}

       {% endif %}