Django 无法分配“u'username'”：“Message.recipient”必须是“User”实例答案

【问题标题】：Django Cannot assign "u'username'": "Message.recipient" must be a "User" instanceDjango 无法分配“u'username'”：“Message.recipient”必须是“User”实例
【发布时间】：2015-01-05 04:52:51
【问题描述】：

为什么我会收到此错误？

我不知道如何摆脱这个错误。如何清理表单字段以验证用户名？

提前致谢。

class InboxCompany(generic.UpdateView):

    model = CandidateToJob
    template_name = 'dashboard/inbox-company.html'
    form_class = ComposeMessage

    def get(self, *args, **kwargs):
        recipient = self.get_object(queryset=CandidateToJob.objects.select_related('candidate'))
        if recipient is not None:
            user = User.objects.get(username=recipient.candidate.user.username)
            self.initial = {'recipient': user}
        return super(InboxCompany, self).get(*args, **kwargs)

forms.py

 class ComposeMessage(ModelForm):
    recipient = forms.CharField(
        required=True,
        widget=forms.TextInput(attrs={'class': 'form-control'})
    )
    body = forms.CharField(
        required=True,
        widget=forms.TextInput(attrs={'class': 'form-control'})
    )

    class Meta:
        model = Message

【问题讨论】：

消息清楚地说明了问题。您正在尝试将 User 分配给 Charfield，这是没有意义的。请记住，您的 receipient 字段是一个外键（我假设），因此它在您的 Message 表中由一个整数值表示。因此，表示该外键关系的表单字段也应该返回一个整数。您是否希望用户能够在表单字段中输入用户名并让它查找该用户并将其保存为recipient？
感谢蒂米的快速反应。我不希望用户在收件人字段中输入用户名。即使我更改 id 的用户名，它也会返回相同的错误。
你想用这个表格做什么？您是否尝试使用用户预填充 receipient 字段，然后验证该用户并在发布表单时将其保存到 receipient 字段？
没错。这是模型： class Message(models.Model): body = models.TextField(_("Body")) sender = models.ForeignKey(AUTH_USER_MODEL, related_name='sent_messages') receiver = models.ForeignKey(AUTH_USER_MODEL, related_name= 'received_messages', null=False, blank=True)
您需要将其添加到您的帖子中。快速解决方法是将这个self.initial = {'recipient': user} 更改为self.initial = {'recipient': user.pk}。如果你想显示他们的用户名，虽然它更复杂。或者，您可以显示系统中所有用户的下拉列表，并允许他们选择一个

标签： python django autofill django-messages

【解决方案1】：

我终于搞定了。

这是我的答案：

views.py

class InboxCompany(generic.UpdateView):

model = CandidateToJob
template_name = 'dashboard/inbox-company.html'
form_class = ComposeMessage

def get_success_url(self):
    return reverse('inboxcompany', kwargs={'pk': self.object.pk})

def get_context_data(self, **kwargs):
    context = super(InboxCompany, self).get_context_data(**kwargs)
    context['message_list'] = Message.objects.inbox_for(self.request.user)
    context['sent_list'] = Message.objects.outbox_for(self.request.user)
    return context

def get_initial(self, *args, **kwargs):
    recipient = self.get_object(queryset=CandidateToJob.objects.select_related('candidate.user.id'))
    self.initial = {'recipient': recipient}
    return self.initial

def get_form_kwargs(self, *args, **kwargs):
    kwargs = {'initial': self.get_initial()}
    return kwargs

def post(self, request, *args, **kwargs):

    form = self.form_class(request.POST)

    if form.is_valid():

        #get data from the form
        data = form.cleaned_data
        body = data['body']

        #auto fill fields
        sender = request.user
        sent_at = timezone.now()
        recipient = self.get_object(queryset=CandidateToJob.objects.select_related('candidate.user.id'))
        user = User.objects.all().get(id=recipient.candidate.user.id)

        a = Message.objects.create(sender=sender, recipient=user, sent_at=sent_at, body=body)
        a.save()


    return HttpResponse('Success')

forms.py

class ComposeMessage(forms.Form):
recipient = forms.CharField(
    required=True,
    widget=forms.HiddenInput(attrs={'class': 'form-control'})
)
body = forms.CharField(
    required=True,
    label="Mensagem",
    widget=forms.TextInput(attrs={'class': 'form-control'})
)

def __init__(self, *args, **kwargs):
    recipient_filter = kwargs.pop('recipient_filter', None)
    super(ComposeMessage, self).__init__(*args, **kwargs)
    if recipient_filter is not None:
        self.fields['recipient']._recipient_filter = recipient_filter


def save(self, sender, parent_msg=None):
    recipients = self.cleaned_data['recipient']
    body = self.cleaned_data['body']
    message_list = []
    for r in recipients:
        msg = Message(
            sender = sender,
            recipient = r,
            subject = subject,
            body = body,
        )
        if parent_msg is not None:
            msg.parent_msg = parent_msg
            parent_msg.replied_at = datetime.datetime.now()
            parent_msg.save()
        msg.save()
        message_list.append(msg)
        if notification:
            if parent_msg is not None:
                notification.send([sender], "messages_replied", {'message': msg,})
                notification.send([r], "messages_reply_received", {'message': msg,})
            else:
                notification.send([sender], "messages_sent", {'message': msg,})
                notification.send([r], "messages_received", {'message': msg,})
    return message_list

models.py

class Message(models.Model):
"""
A private message from user to user
"""
body = models.TextField(_("Mensagem"))
sender = models.ForeignKey(AUTH_USER_MODEL, related_name='sent_messages')
recipient = models.ForeignKey(AUTH_USER_MODEL, related_name='received_messages', null=False, blank=True)
parent_msg = models.ForeignKey('self', related_name='next_messages', null=True, blank=True)
sent_at = models.DateTimeField(null=True, blank=True)

【讨论】：