如何将基于函数的视图转换为基于类的视图

Question

我有一个基于函数的视图，我正在尝试将其转换为基于类的视图 (DetailView)。基于函数的视图相当于 CBV 中的 DetailView。我该怎么办？

这是基于函数的视图

def show_post(request, post):
    """A View to display a single post.
    The post variable here is the slug to a post.
    The slug to a post may possibly be a duplicate. So we filter all posts by 
    the slug (which is the 1st variable here)
    And then select the first post returned by the filter queryset.
    The first post returned is, of course, the post we are trying to view.
    """
    post = Post.objects.filter(slug=post)
    if post.exists():
        post = post[0]
    else:
        return HttpResponseRedirect('/blog/')
     count_visits = None
    unique_views = set()

    if request.user.is_authenticated:
        post_views = PostView.objects.filter(post=post)
        count_visits = post_views.count()
        for post_view in post_views:
            unique_views.add(post_view.ip)
    else:
        post_view = PostView(post=post, ip=request.META.get('REMOTE_ADDR',''),
                      http_host=request.META.get('HTTP_HOST', ''),
                      http_referrer=request.META.get('HTTP_REFERER',''),                    
                      http_user_agent=request.META.get('HTTP_USER_AGENT', ''),
                             remote_host=request.META.get('REMOTE_HOST', ''))
        post_view.save()

    c = {
        'post': post,
        'comments': comments,
        'new_comment': new_comment,
        'similar_posts': similar_posts,
        'count_visits': count_visits,
        'unique_views': unique_views,
        'comments_count': comments_count,
        'message': message,
    }
    return render(request, 'blog/posts/post.html', c)

然后我尝试使用以下方法将其转换为基于类的视图：

class PostDetailView(DetailView):
    model = Post
    template_name = 'blog/post.html'
    context_object_name = 'post'

    def get_context_data(self, **kwargs):
        self.slug = get_object_or_404(Post, slug=self.kwargs['slug'])        
        p = Post.objects.filter(slug=self.slug).first()
        if p.exists():
            p = p[0]
        else:
            return HttpResponseRedirect('/blog/')
        count_visits = None
        unique_views = set()

        if self.request.user.is_authenticated:
            post_views = PostView.objects.filter(post=p)
            count_visits = post_views.count()
            for post_view in post_views:
                unique_views.add(post_view.ip)

        else:
            post_view = PostView(ip=self.request.META.get('REMOTE_ADDR', ''),
                 http_host=self.request.META.get('HTTP_HOST', ''),
                 http_referrer=self.request.META.get('HTTP_REFERER', ''),                               
                 http_user_agent=self.request.META.get('HTTP_USER_AGENT', ''),                                 
                 remote_host=self.request.META.get('REMOTE_HOST', ''))

            post_view.save()

        c = {
            'count_visits': count_visits,
            'unique_views': unique_views,
        }

        return render(self.request, self.template_name, c)

我不确定这是解决此问题的正确方法。请帮助我。

非常感谢。

Answer 1

默认情况下，DetailView 应该负责传递到您的 url 的 pk/slug，因此您不需要在 get_context_data 的前两行中执行查询集。相信一个更清晰的方法看起来像这样：

class PostDetailView(DetailView):
    model = Post
    template_name = 'blog/post.html'
    context_object_name = 'post'

    def get_context_data(self, **kwargs):
        context = super().get_context_data(**kwargs)
        if self.object is None:
            return HttpResponseRedirect(reverse('blog'))

        count_visits = None
        unique_views = set()

        if self.request.user.is_authenticated:
            post_views = PostView.objects.filter(post=self.object)
            count_visits = post_views.count()
            for post_view in post_views:
                unique_views.add(post_view.ip)
        else:
            post_view = PostView.objects.create(
                ip=self.request.META.get('REMOTE_ADDR', ''),
                http_host=self.request.META.get('HTTP_HOST', ''),
                http_referrer=self.request.META.get('HTTP_REFERER', ''),
                http_user_agent=self.request.META.get('HTTP_USER_AGENT', ''),
                remote_host=self.request.META.get('REMOTE_HOST', '')
            )

        context.update({
            'count_visits': count_visits,
            'unique_views': unique_views,
        })

        return context