Django 创建 post

Question

我正在尝试创建一个新的 post 到论坛，它确实有效，我也在打印表格是否有效，但是当我去检查 post 是未 posted。在管理页面中，post 在那里，已批准，但缺少标签和类别字段。它们是在创建 post 时添加的，否则我会收到错误消息。但是我必须在管理页面中手动添加它们才能将 post posted 到论坛。

这是我的Post模型

class Post(models.Model):
    title = models.CharField(max_length=400)
    slug = models.SlugField(max_length=400, unique=True, blank=True)
    user = models.ForeignKey(Author, on_delete=models.CASCADE)
    content = HTMLField()
    categories = models.ManyToManyField(Category)
    date = models.DateTimeField(auto_now_add=True)
    approved = models.BooleanField(default=True)
    tags = TaggableManager()
    comments = models.ManyToManyField(Comment, blank=True)
    # closed = models.BooleanField(default=False)
    # state = models.CharField(max_length=40, default="zero")

    def save(self, *args, **kwargs):
        if not self.slug:
            self.slug = slugify(self.title)
        super(Post, self).save(*args, **kwargs)

    def __str__(self):
        return self.title

这是我的views.py

@login_required
def create_post(request):
    context = {}
    form = PostForm(request.POST or None)
    if request.method == "POST":
        if form.is_valid():
            print("\n\n form is valid")
            author = Author.objects.get(user=request.user)
            new_post = form.save(commit=False)
            new_post.user = author
            new_post.save()

            return redirect('forums')
        
    context.update({
            'form': form,
            'title': 'Create New Post'
    })
    return render(request, 'forums/create_post.html', context)

这个html就很简单了，测试一下。

<form method="POST">
                            {% csrf_token %}    
                            {{form|crispy}}
                            <!-- Submit Post -->
                            <input type="submit" value="Save">
                        </form>

如有任何帮助，我们将不胜感激

Answer 1

行，new_post = form.save(commit=False)不会根据docs保存多对多关系。解决方法

new_post = form.save(commit=False)
new_post.user = author
new_post.save()
form.save_m2m()

摘自docs

Another side effect of using commit=False is seen when your model has a many-to-many relation with another model. If your model has a many-to-many relation and you specify commit=False when you save a form, Django cannot immediately save the form data for the many-to-many relation. This is because it isn’t possible to save many-to-many data for an instance until the instance exists in the database.

To work around this problem, every time you save a form using commit=False, Django adds a save_m2m() method to your ModelForm subclass. After you’ve manually saved the instance produced by the form, you can invoke save_m2m() to save the many-to-many form data.

我认为这并不能解决所有问题，但请尝试一下。

Answer 2

在commit=False时，ModelForm无法保存多对多关系的原因是因为它没有在数据库端创建Post，因此没有可用于添加多对多关系的主键。

您可以使用 .save_m2m() 在保存了包装在表单中的实例后保存多对多关系，但也许更优雅的解决方案是将 request.user 附加到包装的实例在表单中，然后保存表单，从那时起，表单将在同一个函数调用中保存多对多关系，所以：

from django.shortcuts import get_object_or_404

# …

if form.is_valid():
    form<strong>.instance.user =</strong> get_object_or_404(Author, user=request.user)
    form<strong>.save()</strong>

可能值得将 .user 字段重命名为 .author，因为现在它暗示它正在存储一个 User 对象，而不是 Author 对象。

Django 创建 post

Django create post

html

python

django

django-models

django-forms