移除一位宾客

本课属于 Coddy Django 学习旅程的“表单”单元。第 20 课，共 20 课。

组织者需要从访客页面中移除人员。每一行都有自己的小表单，其 action 是该行对应的 URL，因此按钮只会提交该行的数据。下面是一个待办事项列表，每项任务都有一个“完成”按钮：

{% for task in tasks %}
<li>
    {{ task.title }}
    <form method="post" action="{% url 'todo:finish' task.pk %}">
        {% csrf_token %}
        <button type="submit">Done</button>
    </form>
</li>
{% endfor %}

像 finish 这样的视图不会显示页面：它会更改数据并重定向。来自 django.views.decorators.http 的 @require_POST 会拒绝其他类型的请求，并返回 405 Method Not Allowed，因此链接或手动输入的地址都不会移除任何人：

@require_POST
def finish(request, pk):

执行操作后，像之前一样添加一条消息并重定向。

挑战

困难

移除一位来宾。

在 events/urls.py 中，添加名为 remove_rsvp 的 rsvps/<int:pk>/remove/。
在 events/views.py 中，编写 remove_rsvp，并使用 @require_POST（来自 django.views.decorators.http）。它会删除 RSVP，使用来宾的姓名添加消息 Ada was removed from the guest list.，并重定向到来宾页面。
在 guest_list.html 中，为每位来宾添加一个带有 {% csrf_token %} 的 POST 表单，并添加一个会提交到对应 URL 的 Remove 按钮。

移除 Ada 后，只剩下 Grace。

亲手试试

from django.contrib import messages
from django.shortcuts import get_object_or_404, redirect, render

from .forms import EventForm, RSVPForm
from .models import Event


def event_list(request):
    q = request.GET.get("q", "")
    events = Event.objects.all()
    if q:
        events = events.filter(title__icontains=q)
    return render(request, "events/event_list.html", {"events": events, "q": q})


def event_detail(request, pk):
    event = get_object_or_404(Event, pk=pk)
    if request.method == "POST":
        form = RSVPForm(request.POST, event=event)
        if form.is_valid():
            rsvp = form.save(commit=False)
            rsvp.event = event
            rsvp.save()
            messages.success(request, "You're on the list!")
            return redirect("events:detail", pk=event.pk)
    else:
        form = RSVPForm(event=event)
    return render(request, "events/event_detail.html", {"event": event, "form": form})


def new_event(request):
    if request.method == "POST":
        form = EventForm(request.POST)
        if form.is_valid():
            event = form.save()
            messages.success(request, "Your event was added.")
            return redirect("events:detail", pk=event.pk)
    else:
        form = EventForm()
    return render(request, "events/new_event.html", {"form": form})


def edit_event(request, pk):
    event = get_object_or_404(Event, pk=pk)
    if request.method == "POST":
        form = EventForm(request.POST, instance=event)
        if form.is_valid():
            form.save()
            messages.success(request, "Your changes were saved.")
            return redirect("events:detail", pk=event.pk)
    else:
        form = EventForm(instance=event)
    return render(request, "events/edit_event.html", {"form": form, "event": event})


def delete_event(request, pk):
    event = get_object_or_404(Event, pk=pk)
    if request.method == "POST":
        event.delete()
        messages.success(request, "The event was deleted.")
        return redirect("events:list")
    return render(request, "events/delete_event.html", {"event": event})


def guest_list(request, pk):
    event = get_object_or_404(Event, pk=pk)
    return render(request, "events/guest_list.html", {"event": event})