根据ModelChoiceField关系过滤django中表单中的ForeignKey选项
提问于 2017-05-28 09:36:07
在django项目中，我创建了三个模型类。类‘子主题’与类‘章节’有ForeignKey关系，'SAQ‘类与类’章节‘和类’子主题‘有ForeignKey关系。
#models.py
from django.db import models
class Chapter(models.Model):
chapter_serial = models.IntegerField(null=False, help_text="Chapter No.")
slug = models.SlugField(unique=True, blank=True)
chapter_name = models.CharField(max_length=120)
class Meta:
ordering = ["chapter_serial"]
def get_saq_list_url(self):
return reverse("cms:saq_list", kwargs={"chap_slug":self.slug})
class Subtopic(models.Model):
subtopic_serial = models.IntegerField(null=False)
title = models.CharField(max_length=240)
chapter = models.ForeignKey('Chapter', on_delete=models.CASCADE)
class Meta:
ordering = ["subtopic_serial"]
class SAQ(models.Model):
question_serial = models.IntegerField(null=False)
question = models.TextField()
answer = models.TextField()
chapter = models.ForeignKey('Chapter', on_delete=models.CASCADE)
subtopic = models.ForeignKey('Subtopic', on_delete=models.CASCADE, null=True, blank=True)
class Meta:
ordering = ["question_serial"]我尝试使用django ModelForm为“模型SAQ”创建表单，这样对于每个与特定章节实例相关联的'SAQ表单‘，模型'Subtopic’的选择字段将只包含该特定章节实例的那些子主题。
#forms.py
from django import forms
from .models import SAQ
class SAQForm(forms.ModelForm):
class Meta:
model = SAQ
fields = [
'question_serial',
'question',
'answer',
'important',
'remarks',
'subtopic',
]创建表单的django视图函数如下所示。
from django.shortcuts import render, get_object_or_404, redirect
from .models import SAQ, Chapter, Subtopic
from .forms import SAQForm
from django.http import HttpResponseRedirect
def saq_create(request, chap_slug=None):
chapter_instance = get_object_or_404(Chapter, slug=chap_slug)
form = SAQForm(request.POST or None)
if form.is_valid():
instance = form.save(commit=False)
instance.chapter = chapter_instance
instance.save()
return HttpResponseRedirect(chapter_instance.get_saq_list_url())
context = {
"form":form,
"chapter_instance":chapter_instance,
}
return render(request, 'cms/saq_form.html', context)使用此配置，表单中的“Subtopic”选项字段将显示所有章节实例的所有子主题。任何建议都会很有帮助。
回答 1
Stack Overflow用户
回答已采纳
发布于 2017-05-28 13:27:12
我建议重写表单init并传递章节实例，这样您就可以过滤子主题查询集了。
示例(未测试，可能包含键入)：
#forms.py
from django import forms
from .models import SAQ
class SAQForm(forms.ModelForm):
class Meta:
model = SAQ
fields = [
'question_serial',
'question',
'answer',
'important',
'remarks',
'subtopic',
]
def __init__(self, chapter, *args, **kwargs):
super().__init__(*args, **kwargs)
self.fields['subtopic'].queryset = \
self.fields['subtopic'].queryset.filter(chapter=chapter)然后，您的视图应该将章节实例传递给表单：
chapter_instance = get_object_or_404(Chapter, slug=chap_slug)
form = SAQForm(chapter_instance, request.POST or None)页面原文内容由Stack Overflow提供。腾讯云小微IT领域专用引擎提供翻译支持
原文链接：
https://stackoverflow.com/questions/44230164
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