Question

我在使用实例保存表单时遇到问题。我有一个带外键的模型，但我想保存它 - 但表中没有出现任何错误信息。

模型是：

class AboutMe(models.Model):
    MyGender                   = models.CharField(max_length=50, choices = GENDER_CHOICES)


class Message(models.Model):
    MySubject     =  models.CharField(max_length=100)
    MyMessage     =  models.CharField(max_length=100)
    MyFromID      =  models.ForeignKey(AboutMe)

class ContactForm(ModelForm):
    class Meta:
        model = Message
        exclude = ('MyRead', 'MyDeleted', 'MySpam', 'MyDate', 'MyTime', 'MyFromID', 'MyToID')
    MyMessage = forms.CharField(widget=forms.Textarea)

def Contact(request):
        myid = request.session["AboutMe_id"]

        Sender = AboutMe.objects.get(pk=myid)
        if request.method == "POST":
            message = ContactForm(request.POST, instance=Sender)
            if message.is_valid():
                message.save(commit=False)
                #return HttpResponse(myid)
                message.MyRead = False
                message.MyDeleted = False
                message.MySpam = False
                message.MyDate = datetime.date.today()
                message.MyTime = timezone.now()
                message.MyToID = int(1)
                message.save()
                message.save_m2m()
                return redirect('/')
        else:
            message = ContactForm(request.POST, instance=Sender)
        return render(request, "contact.html", {'form': message,})

我也试过这个：

def Contact(request):
    myid = request.session["AboutMe_id"]

    Sender = AboutMe.objects.get(pk=myid)
    if request.method == "POST":
        messageForm = ContactForm(request.POST, instance=Sender)    
        if messageForm.is_valid():
            message = messageForm.save(commit=False)
            #message.save(commit=False)
            #return HttpResponse(myid)
            message.MyRead = False
            message.MyDeleted = False
            message.MySpam = False
            message.MyDate = datetime.date.today()
            message.MyTime = timezone.now()
            message.MyToID = int(1)
            message.save()
            #message.save_m2m()
            return redirect('/')
    else:
        messageForm = ContactForm( instance=Sender)
    return render(request, "contact.html", {'form': messageForm,})

Answer 1

您将错误的实例传递给表单，因为表单适用于Message模型，而不是AboutMe模型。

以下是更正后的版本以及一些其他检查：

您应该始终确保您拥有有效的会话。如果您有request.session["AboutMe_id"]且会话已过期，您将获得KeyError（因为密钥不在会话中）。使用get字典方法将抑制此错误。相反，如果密钥不存在，该方法将返回None。如果会话已过期，我们不应该继续前进 - 所以我们会重定向到根目录。
即使会话有效 - 它也可能不包含模型的有效值。在这种情况下，此AboutMe.objects.get(pk=myid)将引发异常。为了防止这种情况，我们将其包装在try / except块中。如果对象不存在，则表示会话中的值无效。我们删除密钥，然后将用户重定向到根目录。
最后，如果表单无效，您应该始终有条件;所以我也加了检查。

其余的更改主要是格式化。方法名称应以小写字母开头，正常名称也应如此。只有类名应该在InitialCaps中。

def contact(request):
    myid = request.session.get("AboutMe_id")
    if not myid:
        # session has expired
        return redirect('/')
    try:
        sender = AboutMe.objects.get(pk=myid)
    except AbouMe.DoesNotExist:
        # Invalid id in session
        del request.session['AboutMe_id']
        return redirect('/')

    messageForm = ContactForm(request.POST or {})
    if request.method == "POST":      
        if messageForm.is_valid():
            message = messageForm.save(commit=False)
            message.MyRead = False
            message.MyDeleted = False
            message.MySpam = False
            message.MyDate = datetime.date.today()
            message.MyTime = timezone.now()
            message.MyToID = 1
            message.MyFromID = sender
            message.save()
            return redirect('/')
        else:
            # form is not valid
            return render(request, "contact.html", {'form': messageForm})
     else:
         # return empty form
         return render(request, 'contact.html', {'form': messageForm})

具有实例的模型将不会保存到DB但在Django中没有错误消息

1 个答案: