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django - 如何使 Django FormSet 接受 m2m 但将它们存储为多个 FK 记录？

问题描述

我需要为学生提供测试，但有些问题接受多个答案。

我可以让它创建多个记录来存储多个答案而不是使用 M2M 吗？

例如，如果学生为一个问题选择 A 和 B，则行为如下：

StudentAnwer.objects.create(question=question, answer=answer_a)
StudentAnwer.objects.create(question=question, answer=answer_b)

表单集.py

from django import forms

StudentAnswerFormSet = forms.inlineformset_factory(
    Student,
    StudentAnswer,
    fields=['question', 'answer', ],
    formset=forms.BaseInlineFormSet)

模型.py

class Question(BaseModel):
    title = models.CharField(max_length=250)
    is_multiple = models.BooleanField(default=False)

class StudentAnswer(BaseModel):
    student = models.ForeignKey(Student, related_name='answers')
    question = models.ForeignKey(Question, related_name='student_answers')
    answer = models.ForeignKey(Answer, related_name='student_answers')

视图.py

from formtools.wizard.views import SessionWizardView

class StudentWizardView(SessionWizardView):
    ...

    def get_answer_form(self, step=None, data=None, files=None):
        ...

        question_list = get_question_list()

        return forms.inlineformset_factory(
            Student,
            StudentAnswer,
            fields=['question', 'answer', ],
            extra=len(question_list),
            formset= forms.BaseInlineFormSet)

    def get_form(self, step=None, data=None, files=None):
        form = super(StudentWizardView, self).get_form(step, data, files)

        # determine the step if not given
        if step is None:
            step = self.steps.current

        if step == self.STEP_ANSWER:
            initial_dict = self.get_form_initial(step)

            prev_form_data = self.get_cleaned_data_for_step(self.STEP_PROFILE)

            form = self.get_answer_form(step, data, files)

            for form_index in range(len(initial_dict.keys())):
                question = initial_dict[form_index]['question']

                answer_list = question.get_answer_list()

                if question.is_multiple:
                    form.forms[form_index].fields['answer'] = ModelMultipleChoiceField(queryset=answer_list,
                                                                                   widget=CheckboxSelectMultiple)
                else:
                    form.forms[form_index].fields['answer'].widget.choices.queryset = answer_list

我试图避免使用 M2M，以便更轻松地在模板上显示每个问题的可能答案。

{{ wizard.management_form }}
{{ wizard.form.management_form }}

{% for answer_form in wizard.form.forms %}
  {{ answer_form.question }}
  {{ answer_form.answer }}

  {% for hidden in answer_form.hidden_fields %}
    {{ hidden }}
  {% endfor %}
{% endfor %}

标签： django

解决方案

通过使用 rawform.data而不是解决了它form.cleaned_data，因此可以在清理之前访问同一字段的多个值。

这是有风险的，但您可以仅针对您希望它执行的部分复制清理方法。

还通过以下方式制作了一个自定义复选框列表：

{% for choice in field.field.choices %}
  <input type="checkbox" id="id_{{ field.html_name }}_{{ forloop.counter }}" name="{{ field.html_name }}" value="{{ choice.id }}"{% if choice.id in field.value %} checked="checked"{% endif %}> {{ choice }}
{% endfor %}

并删除了自定义表单字段，所以它们都是：

form.forms[form_index].fields['answer'].widget.choices.queryset = answer_list

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