初始数据作为表单集外键字段的查询集

Question

我正在处理英语语言测试申请。每个问题都有问题和 4 个可能的答案。只有一个答案是正确的。以下是型号：

class EnglishTestQuestion(AbstractDatetimeModel):
    text = models.CharField(max_length=255, verbose_name=u"Question text")

class EnglishTestAnswerVariants(models.Model):
    question = models.ForeignKey(EnglishTestQuestion, verbose_name=_(u"question"), related_name='Variants')
    text = models.CharField(max_length=255, verbose_name=u"Text")
    is_correct = models.BooleanField(_(u"Is correct"), default=False)

class EnglishTestAnswer(AbstractDatetimeModel):
    user = models.ForeignKey(User, blank=True, null=True, verbose_name=u"user")
    question = models.ForeignKey(EnglishTestQuestion, blank=False, verbose_name=u"question")
    answer = models.ForeignKey(EnglishTestAnswerVariants, verbose_name=u"answer")

这是风景。我为每个问题创建一个表格并传递初始数据。问题字段获取初始数据，但答案字段忽略它并显示所有答案，：

def english_test(request):
    questions = EnglishTestQuestion.objects.all()
    QuestionFormSet = formset_factory(form=EnglishTestForm, max_num=questions.count())
    formset = QuestionFormSet(initial=[{
                                           'question': x,
                                           'answer': EnglishTestAnswerVariants.objects.filter(question=x)
                                       } for x in questions])

    return render(request, 'testing/english_test.html', {"questions": questions, "question_formset": formset})

但它应该只为每个问题显示那些通过外键连接的答案。

这是表格：

class EnglishTestForm(forms.ModelForm):

    class Meta:
        model = EnglishTestAnswer
        fields = '__all__'
        widgets = {
            'answer': forms.RadioSelect()
        }

如何在 Answer 字段中只传递那些通过 FK 与问题相关的答案？

Answer 1

initial 参数传递字段的初始值，而不是这些字段的可用选项。在您的情况下，您可以动态调整 EnglishTestForm.answer 字段的查询集：

class EnglishTestForm(forms.ModelForm):
    class Meta:
        model = EnglishTestAnswer
        fields = '__all__'
        widgets = {
            'answer': forms.RadioSelect()
        }

    def __init__(self, *args, **kwargs):
        super(EnglishTestForm, self).__init__(*args, **kwargs)
        question = self.initial.get('question')
        if question:
            self.fields['answer'].queryset = question.Variants.all()

P.S.: 实际上你有一个安全问题：恶意用户可以伪造你的表单集值，例如，制作四个具有相同问题 ID 和所有可能答案 ID 的表单。当你盲目地保存那些表格，那么，根据你的计算方法，它可能会导致测试的假阳性结果。只是警告你。

初始数据作为表单集外键字段的查询集

Initial data as queryset for formset foreign key field

django

django-forms

formset