Django同一窗体上的多个自定义模型

Question

我使用的是Django 2.1和PostgreSQL。 我的问题是我试图创建一个表单来同时编辑两个不同的模型。这个模型与FK有关，我看到的每个例子都与用户和概要模型有关，但是我无法复制我真正需要的。你知道吗

我简化的模型显示了它们的相关信息：

# base model for Campaigns.
class CampaignBase(models.Model):
    ....
    project = models.ForeignKey(Project, on_delete=models.CASCADE)
    creation_date = models.DateTimeField(auto_now_add=True)
    start_date = models.DateTimeField(null=True, blank=True)
    end_date = models.DateTimeField(null=True, blank=True)
    ....

# define investment campaign made on a project.
class InvestmentCampaign(models.Model):
    ....
    campaign = models.ForeignKey(CampaignBase, on_delete=models.CASCADE, null=True, blank=True)

    description = models.CharField(
        blank=True,
        max_length=25000,
    )
    ....

我要创建的形式包括FK的end_date和InvestmentCampaign的Description。你知道吗

现在我有了这个UpdateView来编辑投资活动，我需要适应我的实际需要，这也是更新CampaignBase模型的原因：

class ProjectEditInvestmentCampaignView(LoginRequiredMixin, SuccessMessageMixin, generic.UpdateView):
    template_name = 'webplatform/project_edit_investment_campaign.html'
    model = InvestmentCampaign
    form_class = CreateInvestmentCampaignForm
    success_message = 'Investment campaign updated!'

    def get_success_url(self):
        return reverse_lazy('project-update-investment-campaign', args=(self.kwargs['project'], self.kwargs['pk']))

    # Make the view only available for the users with current fields
    def dispatch(self, request, *args, **kwargs):
        self.object = self.get_object()
        # here you can make your custom validation for any particular user
        if request.user != self.object.campaign.project.user:
            raise PermissionDenied()
        return super().dispatch(request, *args, **kwargs)

    # Set field as current user
    def form_valid(self, form):
        campaign = InvestmentCampaign.objects.get(pk=self.kwargs['campaign'])
        form.instance.campaign = campaign
        form.instance.history_change_reason = 'Investment campaign updated'
        return super(ProjectEditInvestmentCampaignView, self).form_valid(form)

    def get_context_data(self, **kwargs):
        project = Project.objects.get(pk=self.kwargs['project'])
        context = super(ProjectEditInvestmentCampaignView, self).get_context_data(**kwargs)
        context['project'] = project
        return context

我的表格是：

class CreateCampaignBaseForm(forms.ModelForm):
    class Meta:
        model = CampaignBase
        fields = ('end_date',)
        widgets = {
            'end_date': DateTimePickerInput(),
        }

    def __init__(self, *args, **kwargs):
        # first call parent's constructor
        super(CreateCampaignBaseForm, self).__init__(*args, **kwargs)
        # evade all labels and help text to appear when using "as_crispy_tag"
        self.helper = FormHelper(self)
        self.helper.form_show_labels = False
        self.helper._help_text_inline = True


class CreateInvestmentCampaignForm(forms.ModelForm):
    class Meta:
        model = InvestmentCampaign
        fields = ('description')
        widgets = {
            'description': SummernoteWidget(attrs={'summernote': {
                'placeholder': 'Add some details of the Investment Campaign here...'}}),
        }

    def __init__(self, *args, **kwargs):
        # first call parent's constructor
        super(CreateInvestmentCampaignForm, self).__init__(*args, **kwargs)
        # evade all labels and help text to appear when using "as_crispy_tag"
        self.helper = FormHelper(self)
        self.helper.form_show_labels = False
        self.helper._help_text_inline = True

我到处都读到这样做的最佳方法是使用基于函数的视图，调用我拥有的每个表单，然后进行验证。问题是，我不知道如何用两种形式的正确对象填充字段，而且，我也不知道如何等效于get\u context\u data，也不知道如何获得self参数来等效于get_success_url（因为对于基于函数的视图，我只有request attr，所以无法访问kwargs）。你知道吗

我见过一些人使用django-betterforms，不过，唯一的例子是auth和profile模型，我看不到用我自己的模型复制它们的方法。你知道吗

非常感谢。你知道吗

Answer 1

如果您只想更改end_date上的一个字段BaseCampaign，那么您应该只使用一个表单。只需在CreateInvestmentCampaignForm上添加end_date作为附加字段（例如forms.DateTimeField()），然后在form.valid()方法中，保存表单后，设置关联活动的值：

def form_valid(self, form):
    inv_campaign = form.save(commit=False)
    inv_campaign.campaign.end_date = form.cleaned_data['end_date']
    inv_campaign.campaign.save()
    inv_campaign.history_change_reason = ...
    return super().form_valid(form)

下面是如何将end_date添加到窗体并正确初始化它：

class CreateInvestmentCampaignForm(ModelForm):
    end_date = forms.DateTimeField(blank=True)

    class Meta:
        model = InvestmentCampaign
        fields = ('description')

    def __init__(self, *args, **kwargs):
        super().__init__(*args, **kwargs)
        if self.instance.campaign:
            self.fields['end_date'].initial = self.instance.campaign.end_date

Answer 2

基于对@dirkgroten答案的讨论，我已经开发出对我有用的东西和我实际使用的东西，但我认为他的答案是正确的，因为他的代码也是功能性的。你知道吗

所以，在他初始化表单上的值的同时，我使用视图来做这件事，添加一个def get_initial(self):并在def form_valid(self, form):上添加验证：

在视图上：

...

    def get_initial(self):
        """
        Returns the initial data to use for forms on this view.
        """
        initial = super(ProjectEditInvestmentCampaignView, self).get_initial()
        initial['end_date'] = self.object.campaign.end_date
        return initial
...
    # Set field as current user
    def form_valid(self, form):
        form.instance.history_change_reason = 'Investment campaign updated'
        is_valid = super(ProjectEditInvestmentCampaignView, self).form_valid(form)
        if is_valid:
            # the base campaign fields
            campaign = form.instance.campaign
            campaign.end_date = form.cleaned_data.get("end_date")
            campaign.save()
        return is_valid

在表单上我刚刚添加了end_date字段：

class CreateInvestmentCampaignForm(forms.ModelForm):
    end_date = forms.DateTimeField()

    class Meta:
        model = InvestmentCampaign
        fields = ('description',)
        widgets = {
            'description': SummernoteWidget(attrs={'summernote': {
                'placeholder': 'Add some details of the Investment Campaign here...'}}),
            'end_date': DateTimePickerInput(),  # format='%d/%m/%Y %H:%M')

        }

    def __init__(self, *args, **kwargs):
        # first call parent's constructor
        super(CreateInvestmentCampaignForm, self).__init__(*args, **kwargs)
        # evade all labels and help text to appear when using "as_crispy_tag"
        self.helper = FormHelper(self)
        self.helper.form_show_labels = False
        self.helper._help_text_inline = True