django - 使用 FormView 和 ModelForm 更新模型 [英] django - update model with FormView and ModelForm

问题描述

我不知道如何在 FormView 中使用 ModelForm 来更新已经存在的实例??

I can't figure out how to use a ModelForm in a FormView so that it updates an already existing instance??

表单在此 URL 上发布:r'/object/(?P<pk>)/'

The form POSTs on this URL: r'/object/(?P<pk>)/'

我使用 ModelForm(而不是直接使用 UpdateView)，因为其中一个字段是必需的，我对其进行了清理.

I use a ModelForm (and not directly an UpdateView) because one of the fields is required and I perform a clean on it.

我基本上想在 FormView(在 POST)中初始化表单时提供 kwarg instance=... 以便它绑定到其pk 在 url 中给出.但我不知道在哪里做...

I'd basically like to provide the kwarg instance=... when initializing the form in the FormView (at POST) so that it's bound to the object whose pk is given in the url. But I can't figure out where to do that...

class SaveForm(ModelForm):
    somedata = forms.CharField(required=False)
    class Meta:
        model = SomeModel  # with attr somedata
        fields = ('somedata', 'someotherdata')
    def clean_somedata(self):
        return sometransformation(self.cleaned_data['somedata'])

class SaveView(FormView):
    form_class = SaveForm
    def form_valid(self, form):
        # form.instance here would be == SomeModel.objects.get(pk=pk_from_kwargs)
        form.instance.save()
        return ...

推荐答案

在与您讨论之后，我仍然不明白您为什么不能使用 UpdateView.如果我理解正确的话，这似乎是一个非常简单的用例.您有一个要更新的模型.并且您有一个自定义表单可以在将其保存到该模型之前进行清洁.似乎 UpdateView 可以正常工作.像这样:

After some discussion with you, I still don't see why you can't use an UpdateView. It seems like a very simple use case if I understand correctly. You have a model that you want to update. And you have a custom form to do cleaning before saving it to that model. Seems like an UpdateView would work just fine. Like this:

class SaveForm(ModelForm):
    somedata = forms.CharField(required=False)

    class Meta:
        model = SomeModel  # with attr somedata
        fields = ('somedata', 'someotherdata')

    def clean_somedata(self):
        return sometransformation(self.cleaned_data['somedata'])


class SaveView(UpdateView):
    template_name = 'sometemplate.html'
    form_class = SaveForm
    model = SomeModel

    # That should be all you need. If you need to do any more custom stuff 
    # before saving the form, override the `form_valid` method, like this:

    def form_valid(self, form):
        self.object = form.save(commit=False)

        # Do any custom stuff here

        self.object.save()

        return render_to_response(self.template_name, self.get_context_data())

当然，如果我误解了你，请告诉我.不过，您应该能够让它发挥作用.

Of course, if I am misunderstanding you, please let me know. You should be able to get this to work though.

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