Django实战篇-论坛回帖视图

from django.shortcuts import render, get_object_or_404, redirect, reverse
from django.contrib.auth.decorators import login_required
from django.views.generic import UpdateView, ListView
from django.utils import timezone
from django.utils.decorators import method_decorator
from django.db.models import Count
from .forms import NewTopicForm, PostForm
from .models import Board, Topic, Post

class PostListView(ListView):
    model = Post
    context_object_name = 'posts'
    template_name = 'board/topic_posts.html'
    # 主题回复列表, 复用分页组件
    paginate_by = 20

    def get_context_data(self, **kwargs):
        # 防止相同用户刷新页面被统计为多次访问 ，使用 会话 sessions
        session_key = 'viewed_topic_{}'.format(self.topic.pk)
        if not self.request.session.get(session_key, False):
            self.topic.views += 1
            self.topic.save()
            self.request.session[session_key] = True

        kwargs['topic'] = self.topic
        return super().get_context_data(**kwargs)

    def get_queryset(self):
        self.topic = get_object_or_404(Topic, board__pk=self.kwargs.get('pk'), pk=self.kwargs.get('topic_pk'))
        queryset = self.topic.posts.order_by('created_at')
        return queryset

@login_required
def reply_topic(request, pk, topic_pk):
    topic = get_object_or_404(Topic, board__pk=pk, pk=topic_pk)

    if request.method == "POST":
        form = PostForm(request.POST)
        if form.is_valid():
            post = form.save(commit=False)
            post.topic = topic
            post.created_by = request.user
            post.save()

            # 更新回复帖子的时间
            topic.last_updated = timezone.now()
            topic.save()

            # 回复帖子 重定向到本页
            topic_url = reverse('users:new_posts', kwargs={"pk": pk, "topic_pk": topic_pk})
            topic_post_url = '{url}?page={page}#{id}'.format(
                url=topic_url,
                id=post.pk,
                page=topic.get_page_count()
            )
            return redirect(topic_post_url)
    else:
        form = PostForm()
    return render(request, 'board/reply_topic.html', {"topic": topic, "form": form})

@method_decorator(login_required, name='dispatch')
class PostUpdateView(UpdateView):
    model = Post
    fields = ('message',)
    template_name = 'board/edit_post.html'
    pk_url_kwarg = 'post_pk'
    context_object_name = 'post'

    # 其他用户可以编辑所有帖子的问题
    def get_queryset(self):
        queryset = super().get_queryset()
        return queryset.filter(created_by=self.request.user)

    def form_valid(self, form):
        post = form.save(commit=False)
        post.updated_by = self.request.user
        post.updated_at = timezone.now()
        post.save()
        return redirect("users:new_posts", pk=post.topic.board.pk, topic_pk=post.topic.pk)