Python UpdateView（基于类的视图）中的成功消息需要PK或ID

我想在UpdateView中发送一条成功消息，其中包含一个链接，允许用户改变对更新的看法。这意味着我需要主键

我无法确定如何在UpdateView中检索主键。其他一切都可以工作，所以你会在我的代码中看到，我有理由将主键硬编码为434

我是所有编程的新手，所以我相信这里有一些愚蠢的东西。我试着一次减少一点我愚蠢的东西。因此，我主要想关注如何检索PK（或ID）。谢谢

网址：

# CLASS BASED VIEWS #
path('event/list', EventListView.as_view(), name='list'),
path('event/detail/<int:pk>', EventDetailView.as_view(), name='detail'),
path('event/create', EventCreateView.as_view(), name='create'),
path('event/update/<int:pk>', EventUpdateView.as_view(), name='update'),

class EventUpdateView(SuccessMessageMixin,UpdateView):

    template_name = 'update.html'
    form_class = EventForm
    success_url = '../list'
    queryset = Event.objects.all()

    def get_object(self, queryset=None):  # here we override the get_object method in UpdateView, don't need queryset
        #obj = Event.objects.get(id=self.kwargs['pk'])
        pk_=self.kwargs.get("pk")
        print("The pk is", pk_)
        return get_object_or_404(Event,pk=pk_)

    def form_valid(self, form):
        return super().form_valid(form)

    message_part_1 = "Record has been updated <a href='unupdate?recordtobeunupdated="
    message_part_2 =  '434'
    message_part_3 = "'>Undo</a>"
    undo_message = message_part_1  + message_part_2 + message_part_3
    success_message = (mark_safe(undo_message))

from django.db import models
from django.urls import reverse

class Event(models.Model):  # This is our database table
    company = models.CharField(default='UL',   max_length=20)
    engine = models.CharField(blank=True, max_length=15)
    date = models.DateTimeField(default=datetime.now, blank=True, null=True)  # default the date to today
    category = models.CharField(max_length=20, choices=CATEGORY_CHOICES, default='Weights')
    description = models.TextField(blank=True, null=True)
    reason = models.TextField(blank=True, null=True)
    assess_date = models.DateTimeField(null=True, blank=True)
    outcome = models.CharField(blank=True, max_length=200)
    # the default is True, it can't be blank
    visible = models.BooleanField(default=True, blank=False)


    def get_absolute_url(self):
        return reverse("SiteEventsAPP: SiteEventsAPP-detail", kwargs={"pk": self.pk})

    # See below __str__(self) is a special method
    # It does a cool thing
    # Whenever Python asks for a string representation of my Event object, this method returns a human-readable version
    # If there is no string method, then Python returns the object type
    # This class method is really only needed for the admin page

    def __str__(self):
        return self.engine  # I have to have a field here. Whatever field I pick will be the field shown in admin

---

以下是用户看到的结果：

您可以使用django内置消息：

# CLASS BASED VIEWS #
path('event/list', EventListView.as_view(), name='list'),
path('event/detail/<int:pk>', EventDetailView.as_view(), name='detail'),
path('event/create', EventCreateView.as_view(), name='create'),
path('event/update/<int:pk>', EventUpdateView.as_view(), name='update'),

class EventUpdateView(SuccessMessageMixin,UpdateView):

    template_name = 'update.html'
    form_class = EventForm
    success_url = '../list'
    queryset = Event.objects.all()

    def get_object(self, queryset=None):  # here we override the get_object method in UpdateView, don't need queryset
        #obj = Event.objects.get(id=self.kwargs['pk'])
        pk_=self.kwargs.get("pk")
        print("The pk is", pk_)
        return get_object_or_404(Event,pk=pk_)

    def form_valid(self, form):
        return super().form_valid(form)

    message_part_1 = "Record has been updated <a href='unupdate?recordtobeunupdated="
    message_part_2 =  '434'
    message_part_3 = "'>Undo</a>"
    undo_message = message_part_1  + message_part_2 + message_part_3
    success_message = (mark_safe(undo_message))

from django.db import models
from django.urls import reverse

class Event(models.Model):  # This is our database table
    company = models.CharField(default='UL',   max_length=20)
    engine = models.CharField(blank=True, max_length=15)
    date = models.DateTimeField(default=datetime.now, blank=True, null=True)  # default the date to today
    category = models.CharField(max_length=20, choices=CATEGORY_CHOICES, default='Weights')
    description = models.TextField(blank=True, null=True)
    reason = models.TextField(blank=True, null=True)
    assess_date = models.DateTimeField(null=True, blank=True)
    outcome = models.CharField(blank=True, max_length=200)
    # the default is True, it can't be blank
    visible = models.BooleanField(default=True, blank=False)


    def get_absolute_url(self):
        return reverse("SiteEventsAPP: SiteEventsAPP-detail", kwargs={"pk": self.pk})

    # See below __str__(self) is a special method
    # It does a cool thing
    # Whenever Python asks for a string representation of my Event object, this method returns a human-readable version
    # If there is no string method, then Python returns the object type
    # This class method is really only needed for the admin page

    def __str__(self):
        return self.engine  # I have to have a field here. Whatever field I pick will be the field shown in admin

def form_valid(self, form):
        messages.add_message(
            self.request, 
            messages.SUCCESS, 
            """
            Record has been updated <a href="unupdate?recordtobeunupdated={}">Undo</a>""".format(
                kwargs={'pk': self.kwargs['pk']}
             """"
        )

        return super(UserUpdate, self).form_valid(form)

def form_有效（self，form）：
messages.add_消息(
自我要求，
信息，成功，
"""
记录已更新为“”。格式为“”(
kwargs={'pk'：self.kwargs['pk']}
""""
)
返回super（UserUpdate，self）.form\u有效（form）

使用kwargs={'pk'：self.kwargs['pk']}您将获得id

之后，您可以在模板中捕获消息：

{% if messages %}
    {% for msg in messages %}
      <div class="alert
      alert-{% if msg.level_tag == 'debug' %}rose{% endif %}
      {% if msg.level_tag == 'info' %}info{% endif %}
      {% if msg.level_tag == 'success' %}success{% endif %}
      {% if msg.level_tag == 'warning' %}warning{% endif %}
      {% if msg.level_tag == 'error' %}danger{% endif %} alert-with-icon" data-notify="container">
        <i class="material-icons" data-notify="icon">
          {% if msg.level_tag == 'debug' %}code{% endif %}
          {% if msg.level_tag == 'info' %}info{% endif %}
          {% if msg.level_tag == 'success' %}done_all{% endif %}
          {% if msg.level_tag == 'warning' %}warning{% endif %}
          {% if msg.level_tag == 'error' %}error{% endif %}
        </i>
        <button type="button" class="close" data-dismiss="alert" aria-label="Close">
          <i class="material-icons">close</i>
        </button>
        <span data-notify="message">
          {% autoescape off %}
            {{ msg.message }}
          {% endautoescape %}
        </span>
      </div>
    {% endfor %}
  {% endif %}

{%if消息%}
{消息%中的msg为%0}
{%if msg.level_标记=='debug'}代码{%endif%}
{%if msg.level_标记=='info%}info{%endif%}
{%if msg.level_标记=='success%}done_all{%endif%}
{%if msg.level_标记=='警告'%}警告{%endif%}
{%if msg.level_标记=='错误'%}错误{%endif%}
关闭
{%autoescape off%}
{{msg.message}}
{%endautoescape%}
{%endfor%}
{%endif%}

上面的代码捕获每条消息（假设您使用的是常规布局），并使用引导将消息呈现为通知

---

更多信息

如果您检查成功消息的代码，您将看到：

    class SuccessMessageMixin:
    """
    Add a success message on successful form submission.
    """
    success_message = ''

    def form_valid(self, form):
        response = super().form_valid(form)
        success_message = self.get_success_message(form.cleaned_data)
        if success_message:
            messages.success(self.request, success_message)
        return response

    def get_success_message(self, cleaned_data):
        return self.success_message % cleaned_data

正如您在这里看到的，返回成功消息的函数是

get\u success\u message

，因此您只需重写该函数

您的代码应该是：

class EventUpdateView(SuccessMessageMixin,UpdateView):

    template_name = 'update.html'
    form_class = EventForm
    success_url = '../list'
    queryset = Event.objects.all()    

    def form_valid(self, form):
        return super().form_valid(form)

    def get_success_message(self, cleaned_data):
        message = "Record has been updated <a href='unupdate?recordtobeunupdated="
        message += str(self.kwargs.get("pk"))
        message += "'>Undo</a>"
        return (mark_safe(message))

class EventUpdateView（成功消息更新视图）：
模板名称='update.html'
form\u class=EventForm
成功\u url=“../list”
queryset=Event.objects.all（）
def表单_有效（自身、表单）：
返回super（）.form_有效（form）
def get_success_消息（自身、已清理的_数据）：
message=“记录已更新”
返回（标记安全（消息））

让我给你一个建议，永远不要将python库/框架视为黑盒实体，只需输入它们并探索它们是如何工作的，这将使您的编程生活更加轻松

---

祝你好运，继续努力吧！

你打算如何处理这个成功消息？它不是任何内置的基于类的视图的标准属性。Daniel，我在上面添加了一个片段来向你展示“撤消”是什么需要PK。但是如果你有更好的想法，我很感兴趣。是的，但是你打算如何将该消息从类传递到模板？（此外，它不会影响您的问题，但请注意，您的

get\u对象

方法是不必要的-它只执行默认实现已经执行的操作。只有当您想执行异常操作时，才需要重写

get\u对象

。您应该删除您的版本。）好的，可以。这是一次试图检索PK的尝试，但失败了。谢谢，Hagyn。这成功了，我理解。正如Daniel指出的，我删除了不必要的get_对象，我将您的最后一行代码编辑为message而不是undo_message。很高兴它成功了！我想您也可以删除form_valid方法，您只是在调用super。好的，我删除了有效的表格。再次感谢。