使用 postgres arrayfield 中的值在 django 视图中渲染下拉列表

Question

这是模型中的一个示例：

class Shipment(models.Model):
    shipment_id = models.BigAutoField(null=False, primary_key=True)
    potential_shipping_dates = ArrayField(models.DateField(), verbose_name='Ship Dates', null=True)

以下是我尝试的形式：

class ShippingForm(forms.Form):
    potential_shipping_dates = forms.ModelChoiceField(queryset=Shipment.objects.all())
    def __init__(self, *args, **kwargs):
        super(ShippingForm, self).__init__(*args, **kwargs)

这是我的表单被添加到上下文的地方：

context['shippingForm'] = ShippingForm(initial=??what_goes_here_maybe??)

我的表单渲染得很好，但我想为每个选项显示一个带有日期的下拉列表。

Answer 1

好的，这有点复杂，但我想我理解你想要做什么，以及你哪里出错了。

所以你有一个 Shipment 模型，每个 Shipment 实例都有一个字段，其中包含几个不同的potential_shipping_dates。

假设您有 2 批货物：

IN : ship1 = Shipment.objects.first()
OUT:

IN : ship1.potential_shipping_dates
OUT: ['01/01/2021', '02/02/2021']

IN : ship2 = Shipment.objects.last()
OUT:

IN : ship2.potential_shipping_dates
OUT: ['03/03/2021', '04/04/2021']

现在，您是否希望下拉列表中包含所有 4 个日期，并且会选择 Shipment？

或者您想在表格中选择发货后选择日期？

^^ 在 cmets 中回答

好的，您需要将实例传递给表单：

views.py

# Inherit from Django's UpdateView to have `instance` passed through to the form
class ShippingFormView(UpdateView):
    model = Shipment
    form_class = ShippingForm


# Or if you don't want to inherit from inherit from UpdateView
class ShippingFormView(Blah):
    model = Shipment
    form_class = ShippingForm

    def get_form_kwargs(self):
        kwargs = super().get_form_kwargs()
        kwargs['instance'] = self.get_object()
        return kwargs


# Or if you're using function based views
def shipping_form_view(request, pk):
    shipment = get_object_or_404(Shipment, pk=pk)
    form = ShippingForm(request, instance=shipment)
    ...

forms.py

class ShippingForm(forms.Form):
    potential_shipping_dates = forms.ChoiceField(choices=[])

    def __init__(self, *args, instance, **kwargs):
        super(ShippingForm, self).__init__(*args, **kwargs)
        self.fields['potential_shipping_dates'].choices = ((dt, dt) for dt in instance.potential_shipping_dates)

ModelChoiceFields 用于选择object，而不是一个属性。