如何在 FormMixin 和 DetailView 中设置初始数据

Question

我想使用通用外键创建评论表单，但是在获取表单中 object_id 和 content_type 的初始数据时遇到了麻烦？

class Comment(models.Model):
    user    =   models.ForeignKey(User, on_delete=models.CASCADE)
    content_type=   models.ForeignKey(ContentType, on_delete=models.CASCADE)
    object_id   =   models.PositiveIntegerField()
    content_object=   GenericForeignKey()
    parent=   models.ForeignKey("self", null=True, blank=True, on_delete=models.CASCADE)
    content  =   RichTextField()
    time_stamp  =   models.DateTimeField(auto_now_add=True)

Forms.py

class CommentsForm(forms.ModelForm):
    content_type    =   forms.CharField(widget=forms.HiddenInput)
    object_id       =   forms.IntegerField(widget=forms.HiddenInput)
    content         =   forms.CharField(widget=forms.Textarea(attrs={
        'class':'form-control',
        'cols':'4',
        'rows':'3'
    }))

    class Meta:
        model   =   Comment
        fields  =   ['content','user','object_id', 'content_type']

Views.py

class SongDetail(FormMixin, DetailView):
    model       =   Song
    form_class  =   CommentsForm

    def post(self, request, *args, **kwargs):
        obj = self.get_object()
        if not request.user.is_authenticated:
            return redirect('music:obj.get_absolute_url()')

        if form.is_valid():
            form.save()
            return self.form_valid(form)

Answer 1

你可以这样试试：

class SongDetail(ModelFormMixin, DetailView):
    model       =   Song
    form_class  =   CommentsForm

    def get_initial(self):
        obj = self.get_object()
        return { 'content_type': obj.content_type, 'object_id': obj.object_id }

    def post(self, request, *args, **kwargs):
        if not request.user.is_authenticated:
            return redirect('music:obj.get_absolute_url()')
        
        form = self.get_form()
        if form.is_valid():
            return self.form_valid(form)
        else:
            return self.form_invalid(form)

仅供参考，我使用的是ModelFormMixin 而不是FormMixin，因为它提供了内置的保存功能。

在这里，我将覆盖 get_initial 方法以从中返回 content_type 和 object_id。然后将这些值传递给表单并作为初始值加载。