如何在 Django ModelForm 中显示 CHOICES

Question

我有一个包含 16 个类别的 policy_category 模型。
我有一个 Response 模型来记录调查答案。该模型包括一个字段，用于记录受访者对每个政策类别的 1-5 评级。 (policy_1_rank..policy_16_rank, 等等)

我不知道如何显示我为每个字段创建的 CHOICES：

Form Template

 <div><b>How important are each of the following issues or policy areas to you, when you're selecting a candidate for president?</b></div>
<div><br></div>
<ul><div>{{ policy_category.object(pk=1) }}</div></ul>
# show POLICY_1_CHOICES below:
<div>{{ form.policy_1_rank }}</div>

<div><br></div>
<ul><div>{{ policy_category.object(pk=2) }}</div></ul>
# show POLICY_2_CHOICES below:
<div>{{ form.policy_2_rank }}</div>
...

Responses Model:

# Temp Survey Response
class Temporaryresponse(models.Model):
    # Healthcare
    POLICY_1_CHOICES = [
    (1, '1: Extremely supportive of a healthcare system with ONLY private insurance'),
    (2, '2: Somewhat supportive of a healthcare system with ONLY private insurance'),
    (3, '3: Somewhat supportive of a healthcare system with BOTH private insurance and a public insurance option'),
    (4, '4: Extremely supportive of a healthcare system with BOTH private insurance and a public insurance option'),
    (5, '5: Somewhat supportive of a healthcare system with ONLY public insurance (commonly referred to as "universal healthcare")'),
    (6, '6: Extremely supportive of a healthcare system with ONLY public insurance (commonly referred to as "universal healthcare")'),
]
...
# Healthcare
    policy_1_rank = models.IntegerField(blank=True, default=0, choices=POLICY_1_CHOICES)

Forms.py

class NextresponseForm(ModelForm):
    policy_1_rank = forms.IntegerField()
    policy_2_rank = forms.IntegerField()
...

class Meta:
        model = Temporaryresponse
        fields = ['policy_1_rank', 'policy_2_rank',...]

编辑：也许下面的答案不起作用，因为我的观点有问题。我正在尝试从第一个表单页面 "tr.html" 导航，保存数据，然后将响应的 pk 发送到 "nr.html" 以进行调查的第二部分。这是工作。但是我对"nr.html"的看法不正确吗？

views.py

# Create temporary response view - this saves and goes to nr perfectly. pk produced from saving the response shows in nr link in web browser (myapp/nr/pk# shows here perfectly.)
def tr(request):
    if request.method == "POST":
        form = TemporaryresponseForm(request.POST)
        if form.is_valid():
            tempresponse = form.save()
            tempresponse.save()
            return redirect('nr', pk=tempresponse.pk)
    else:
        form = TemporaryresponseForm()
    return render(request, 'politicalexperimentpollapp/tr.html', {'form': form})


def nr(request, pk):
    tempresponse = get_object_or_404(Temporaryresponse, pk=pk)
    instance = Temporaryresponse.objects.get(pk=pk)
    if request.method == "POST":
        form = NextresponseForm(request.POST, instance=instance)
        if form.is_valid():
            nextresponse = form.save()
            nextresponse.save()
            return redirect('fr', pk=nextresponse.pk)
    else:
        form = NextresponseForm(instance=instance)
    return render(request, 'politicalexperimentpollapp/nr.html', {'tempresponse': tempresponse}, {'form': form})

Answer 1

您可以覆盖 __init__ 中的表单字段以包含 forms.ChoiceField:

class NextresponseForm(ModelForm):  
    def __init__(self, *args, **kwargs):
        super().__init__(*args, **kwargs)
        self.fields['policy_1_rank'] = forms.ChoiceField(
            choices=self._meta.model.POLICY_1_CHOICES)

    class Meta:
            model = Temporaryresponse
            fields = ['policy_1_rank', 'policy_2_rank',...]

更新

在 Django 中呈现表单对象的最简单方法是将其作为视图中的上下文传递：

def some_view(request):
    form = NextresponseForm(request.POST or None)
    context = {'form':form}
    return render(request, 'some_template.html', context)

然后您可以通过在模板中调用 form.as_ul 来访问表单：

<ul>
{{ form.as_ul }}
</ul>

更新 2

您观点中的最后一行不正确：

return render(request, 'politicalexperimentpollapp/nr.html', {'tempresponse': tempresponse}, {'form': form})

这应该是：

return render(request, 'politicalexperimentpollapp/nr.html', {'tempresponse': tempresponse, 'form': form})

context 是一个字典。如果需要将多个项目传递给模板，则需要在上下文字典中包含多个键，而不是多个参数。

最后，我建议始终使用 request.POST or None 初始化表单，以避免使您的表单无效：

    form = TemporaryresponseForm(request.POST or None)

这是对一个常见问题的教科书式回答 "Why is form.is_valid() always invalid?".

如何在 Django ModelForm 中显示 CHOICES

How to display CHOICES in Django ModelForm

django-models

django-forms

limit-choices-to

django-model-field

更新

更新 2