我有一个名为 BlogPost 的模型和一个名为 Category 的模型,每个 BlogPost 可以有多个类别。从管理面板创建帖子时,我没有任何问题,但是当尝试实现创建 BlogPost 以便用户可以创建帖子的表单时,我收到错误:
Direct assignment to the forward side of a many-to-many set is prohibited. Use categories.set() instead.
我尝试阅读文档,但有些东西我不理解,因为它不起作用。
我的模型是这个;
class BlogPost(models.Model):
title = models.CharField(max_length=250)
content = models.TextField()
post_author = models.CharField(max_length=30)
creation_date = models.DateTimeField(auto_now_add=True)
modification_date = models.DateTimeField(auto_now=True)
image = models.ImageField(upload_to='blog/files/blog_images')
categories = models.ManyToManyField('Category', related_name='posts') #Relaciona el atributo con la clase Category y permite usar category.posts
def __str__(self):
return self.title
class Meta:
verbose_name = "blog post"
verbose_name_plural = "blog posts"
class Category(models.Model):
cat_name = models.CharField(max_length=50)
def __str__(self):
return self.cat_name
class Meta:
verbose_name = "category"
verbose_name_plural = "categories"
这是表格:
class newPostForm(forms.Form):
CATEGORIES = (
(1, "Agua dulce"),
(2, "Agua marina"),
(3, "Primer acuario"),
(4, "Alimentación")
)
título = forms.CharField(max_length=250)
contenido = forms.CharField(
widget=forms.Textarea()
)
imagen = forms.ImageField()
autor = forms.CharField()
categorias = forms.ModelMultipleChoiceField(
queryset=Category.objects.all(),
widget=forms.CheckboxSelectMultiple
)
这就是观点:
def new_post(request):
if request.method == "POST":
form = newPostForm(request.POST, request.FILES)
if form.is_valid():
info = form.cleaned_data
new_post_info = BlogPost(
title=info["título"],
content=info["contenido"],
image=info["imagen"],
post_author=info["autor"],
categories=info["categorias"]
)
new_post_info.save()
return redirect(request.path_info)
else:
form = newPostForm()
return render(request, "blog/new_post.html", {"form":form})
欢迎任何建议!
我之前尝试过保存并添加文档中所述的类别,但没有成功。
我解决了,这就是任何想知道的人的方法:
将视图修改为:
def new_post(request):
if request.method == "POST":
form = newPostForm(request.POST, request.FILES)
if form.is_valid():
info = form.cleaned_data
new_post_info = BlogPost(
title=info["título"],
content=info["contenido"],
image=info["imagen"],
post_author=info["autor"],
)
new_post_info.save()
new_post_info.categories.set(info["categorias"])
return redirect(request.path_info)
else:
form = newPostForm()
return render(request, "blog/new_post.html", {"form":form})
现在,它会在保存 new_post_info 对象后,将存储在表单“categorias”字段中的内容传递给 BlogPost 对象属性类别。
PD:我不知道回答自己的问题是否是一种习惯,但这可能会对将来的某人有所帮助。