如何比较 Django 模板中的 IntegerChoice 值

Question

我打算在 Django 模板中比较 IntegerChoice 的值：

class SomeModel(models.Model):
    class Answer(models.IntegerChoices):
        NO = 0, _('No')
        YES = 1, _('Yes')
    
        __empty__ = _('(Unknown)')
    answer = models.IntegerField(choices=Answer.choices)

SomeModel.objects.create(answer=0)
somemodel = SomeModel.objects.filter(answer=0)

Inside template :

{% if somemodel.answer == SomeModel.Answer.YES %}
    ...
{% else %}
    <h1>{{ somemodel.get_answer_display() }}</<h1>
{% endif %}

然而，这并没有进入真正的 if 情况，也不喜欢 "SomeModel.get_answer_display" 末尾的 "()" 以及以下消息：

Could not parse the remainder: '()' from 'SomeModel.get_answer_display()'

内景：

class BrowseView(View):
    @method_decorator(login_required(login_url='/login/'))
    def get(self, request):
        somemodel = SomeModel.objects.all()
        return render(self.request, 'browse/index.html',
                      {
                       'somemodel': somemodel
                      })

如何使过滤器按预期工作？

Answer 1

在模板中你不调用函数：如果某些东西是可调用的，Django 将调用不带参数的可调用对象，因此你可以这样渲染：

{% if somemodel.answer == SomeModel.Answer.YES %}
    …
{% else %}
    <h1>{{ somemodel.get_answer_display }}</<h1>
{% endif %}

您还应该使用模型对象，所以somemodel，而不是SomeModel。

在您看来，您需要同时传递somemodel 对象 和对SomeModel 的引用类：

from django.contrib.auth.mixins import LoginRequiredMixin

class BrowseView(LoginRequiredMixin, View):
    login_url = '/login/'
    
    def get(self, request):
        somemodel = SomeModel.objects.all()
        return render(
            self.request,
            'browse/index.html',
            {'somemodel': somemodel, 'SomeModel': SomeModel}
        )

这里somemodel 也不是模型对象，它是SomeModels 的QuerySet（一个集合）。因此，您应该列举这些：

from django.contrib.auth.mixins import LoginRequiredMixin

class BrowseView(LoginRequiredMixin, View):
    login_url = '/login/'

    def get(self, request):
        somemodels = SomeModel.objects.all()
        return render(
            self.request,
            'browse/index.html',
            {'somemodels': somemodels, 'SomeModel': SomeModel}
        )

并在模板中枚举集合：

{% for somemodel in somemodels %}
    …
{% endfor %}

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注意：您可以将视图限制为基于类的视图，以向经过身份验证的用户提供 LoginRequiredMixin mixin [Django-doc].