Django CBV-Formsets:“NoneType”对象没有属性“id”

Question

我正在与Django CBV合作，我第一次尝试使用表单集。我想同时填写两个表单，并将外键作为两者之间的公共元素。

我有两种型号:

class Publication(models.Model):
    title = models.CharField(max_length=512, verbose_name=_('title'), null=False, unique=True)
    description = models.TextField(verbose_name=_('description'), null=True)
    download_limit = models.IntegerField(verbose_name=_('download limit'), null=True)
    time_limit = models.IntegerField(verbose_name=_('expiration delay'), null=True)
    category = models.ForeignKey(Category, verbose_name=_('category'), null=False)
    nb_document = models.IntegerField(verbose_name=_('number of document'), default=0)
    creation_date = models.DateTimeField(auto_now_add=True, verbose_name=_('creation date'), null=False)
    modification_date = models.DateTimeField(auto_now=True, verbose_name=_('modification date'), null=False)

    class Meta:
        verbose_name = _('publication')
        verbose_name_plural = _('publication')

    def __str__(self):
        return f"{self.title}"


class Document(models.Model):

    FORMAT_CHOICES = (
        ('pdf', 'pdf'),
        ('epub', 'epub'),
    )
    age_id = models.CharField(max_length=12, verbose_name=_('publication ID'), unique=True, default='')
    language = models.CharField(max_length=2, verbose_name=_('language'), null=False)
    format = models.CharField(max_length=10, verbose_name=_('format'), choices=FORMAT_CHOICES, null=False)
    title = models.CharField(max_length=512, verbose_name=_('title'), null=False)
    publication = models.ForeignKey(Publication, verbose_name=_('publication'), null=False, related_name='documents')
    upload = models.FileField(upload_to='media/', validators=[validate_file_extension])
    creation_date = models.DateTimeField(auto_now_add=True, verbose_name=_('creation date'), null=False)
    modification_date = models.DateTimeField(auto_now=True, verbose_name=_('modification date'), null=False)

    class Meta:
        verbose_name = _('document')
        verbose_name_plural = _('document')

    def __str__(self):
        return f"{self.age_id} : {self.title} - {self.publication}"

我在我的表单python文件中定义了表单集：

class PublicationForm(forms.ModelForm):

    def __init__(self, *args, **kwargs):
        super().__init__(*args, **kwargs)
        self.fields['category'].empty_label = _('Select a category')  # Modify initial empty_label

    class Meta:
        model = Publication
        fields = ['title', 'category']


class DocumentForm(forms.ModelForm):

    class Meta:
        model = Document
        fields = ['publication', 'age_id', 'language', 'format', 'title', 'upload']


DocumentFormSet = inlineformset_factory(Publication, Document, form=DocumentForm, extra=1)

最重要的是，我的视图是在cruds.py文件中定义的，如下所示:

class PublicationCreateView(AgeCreateView):

    model = Publication
    template_name = 'app/publication_form.html'

    def get_context_data(self, **kwargs):
        context = super(PublicationCreateView, self).get_context_data(**kwargs)

        if self.request.POST :
            context['document_form'] = DocumentFormSet(self.request.POST, self.request.FILES)
        else:
            context['document_form'] = DocumentFormSet()
        return context

    def form_valid(self, form):
        context = self.get_context_data()
        document = context['document_form']
        if document.is_valid():
            document.instance = self.object
            document.save()
        return super(PublicationCreateView, self).form_valid(form)

    def get_success_url(self):
        return reverse('publication-list-crud')




class PublicationCRUDView(MainConfigCRUDManager):
    """ CRUD views for Publication """
    model = Publication
    default_sort_params = ('category', 'asc')

    templates = {'create': 'app/publication_form.html'}

    custom_views = {'create': PublicationCreateView}

    #queryset = Publication.objects.annotate(nb_documents=Count('documents'))

    # Configuration of fields
    search_fields = ['category', 'title']
    list_fields = ['category', 'title', 'creation_date', 'modification_date', 'nb_document']
    update_fields = ['category', 'title']


class DocumentCRUDView(MainConfigCRUDManager):
    """ CRUD views for Document """
    model = Document
    default_sort_params = ('title', 'asc')

    templates = {'create': 'app/publication_form.html'}

    custom_views = {'create': PublicationCreateView}

    # Configuration of fields
    search_fields = ['age_id', 'title', 'language', 'publication_id.title', 'format']
    list_fields = ['age_id', 'title', 'publication', 'language', 'format']
    update_fields = ['publication', 'age_id', 'title', 'language', 'format', 'upload']

该模板显示良好，具有通用的表单集，但当我想提交这个组合的表单时，我得到了这个问题:

异常值:“NoneType”对象没有属性“id”

这是回溯:

追踪：

文件“/首页/.pyenv/versions/Publication3.6.2/lib/python3.6/站点包/django/核心/处理程序/异常.py”在内部 41 中。响应 = get_response（请求）

文件“/首页/.pyenv/versions/Publication3.6.2/lib/python3.6/site-packages/django/core/处理程序/base.py”，_get_response 187。响应 = self.process_exception_by_middleware（e， 请求）

_get_response 185中的文件“/home/.pyenv/versions/Publication3.6.2/lib/python3.6/site-packages/django/core/handlers/base.py”。响应=wrapped_callback（请求，*callback_args，**callback_kwargs）

文件"/home/. pyenv/version/Publication3.6.2/lib/python3.6/site-包/django/view/通用/base.py"在视图68.返回self.dispatch（请求，*参数，**kwargs）

在调度 56 中将文件“/主页/.pyenv/versions/Publication3.6.2/lib/python3.6/site-packages/django/contribs/auth/mixins.py”。返回超级（登录要求Mixin，自我）.dispatch（请求，*args， **kwargs）

dispatch 116.return super中的文件“/home/.pyenv/versions/Publication3.6.2/lib/python3.6/site-packages/django/contrib/auth/mixins.py”（UserPassesTestMixin，self）。分派（请求，*args，**kwargs）

文件"/home/。pyenv/versions/publication 3 . 6 . 2/lib/python 3.6/site-packages/django/views/generic/base . py "。返回处理程序(请求，*参数，*kwargs)

post 217.return super（BaseCreateView，self）中的文件“/home/.pyenv/versions/Publication3.6.2/lib/python3.6/site-packages/django/views/generic/edit.py”。post（请求，*args，**kwargs）

post 183中的文件“/home/.pyenv/versions/Publication3.6.2/lib/python3.6/site-packages/django/views/generic/edit.py”return self.form_valid（form）

form_valid 49中的文件“/home/Bureau/Projets/Publication/Publication/src/web/app/cruds . py”。document.save()

文件/home/. pyenv/version/Publication3.6.2/lib/python3.6/site-pack/django/form/models.py保存666.返回self.save_existing_objects（提交）self.save_new_objects（提交）

文件"/home/。pyenv/versions/publication 3 . 6 . 2/lib/python 3.6/site-packages/django/forms/models . py”。self . new _ objects . append(self . save _ new(form，commit=commit))

文件"/home/。pyenv/versions/publication 3 . 6 . 2/lib/python 3.6/site-packages/django/forms/models . py”。pk_value = getattr(self.instance，self . fk . remote _ field . field _ name)

异常类型：/crud/publication/create/Exception值处的AttributeError:“NoneType”对象没有属性“id”

我不太清楚id在哪里定义，以及如何解决这个问题。

谢谢你




Answer 1

匿名用户

我找到了答案，但不知道为什么现在行得通，以前行不通。

前面的< code>form_valid()函数:

def form_valid(self, form):
        context = self.get_context_data()
        document = context['document_form']
        if document.is_valid():
            document.instance = self.object
            document.save()
        return super(PublicationCreateView, self).form_valid(form)

这是我的新form_valid（）函数：

def form_valid(self, form):
    context = self.get_context_data()
    document = context['document_form']
    if document.is_valid():
        self.object = form.save() #I added this line
        document.instance = self.object
        document.save()
    return super(PublicationCreateView, self).form_valid(form)