基于类视图下，如何将评论作者默认设为当前登录用户？

我需要实现提交评论时，将评论的作者字段自动设置为当前登录用户，使用的是Django基于类的视图（Class Based Views）。尝试过多种方法但均未奏效，包括修改表单字段、在视图中设置form.instance.author或comment.author等。

现有代码 #

views.py #

class CommentPost(SingleObjectMixin, FormView):
    model = Article
    form_class = CommentForm
    template_name = "article_detail.html"

    def post(self, request, *args, **kwargs):
        self.object = self.get_object()
        return super().post(request, *args, **kwargs)

    def form_valid(self, form):
        comment = form.save(commit=False)
        form.instance.author = self.request.user
        comment.article = self.object
        comment.save()
        return super().form_valid(form)

    def get_success_url(self):
        article = self.get_object()
        return reverse("article_detail", kwargs={"pk": article.pk})

models.py #

class Comment(models.Model):
    article = models.ForeignKey(Article, on_delete=models.CASCADE)
    comment = models.CharField(max_length=140)
    author = models.ForeignKey(
        settings.AUTH_USER_MODEL,
        on_delete=models.CASCADE,
    )

    def __str__(self):
        return self.comment

    def get_absolute_url(self):
        return reverse("article_list")

article_detail.html #

<!-- templates/article_detail.html -->
{% extends 'base.html' %}
{% load crispy_forms_tags %}
{% block content %}
<body class="d-flex h-100">

<div class="container">
    <div class="col-8 mx-auto">
        <h3 class="pb-4 mb-4 fst-italic border-bottom">Article detail</h3>
        <div class="article-entry">
            <h2>{{object.title}}</h2>
            <p class="text-black-50 fst-italic">by {{object.author}} | {{object.date}}</p>
            <p>{{object.body}}</p>
        </div>
        {% if user.is_authenticated and user == article.author or user.is_superuser %}
        <p>
            <button class="btn">
                <a class="text-decoration-none text-white" href="{% url 'article_edit' article.pk %}">edit</a>
            </button>
            <button class="btn">
                <a class="text-decoration-none text-white" href="{% url 'article_delete' article.pk %}">delete</a>
            </button>
        </p>
        {% endif %}
        <br/>
        {% if article.comment_set.all %}
        <hr/>
        <h5>Comments</h5>
        {% for comment in article.comment_set.all %}
        <p>{{ comment.author }} &#8211; {{ comment }}</p>
        {% endfor %}
        {% endif %}
        <br/>
        <hr/>
        <h5>Add a comment</h5>
        <form action="" method="post"> {% csrf_token %}
            {{ form|crispy }}
            <button class="btn" type="submit">Save</button>
        </form>
        <br/>
        <p>Back to <a href="{% url 'article_list' %}">all articles</a></p>
    </div>
</div>
</body>
{% endblock content%}

forms.py #

class CommentForm(forms.ModelForm):
    class Meta:
        model = Comment
        fields = ("comment", "author")

解决方案 #

1. 修改表单，移除作者字段 #

不需要让用户手动选择作者，因此在forms.py中移除author字段：

class CommentForm(forms.ModelForm):
    class Meta:
        model = Comment
        fields = ("comment",)

2. 修正视图中的form_valid方法 #

之前的代码同时操作了comment和form.instance，导致赋值冲突。直接对form.save(commit=False)返回的实例赋值即可：

def form_valid(self, form):
    comment = form.save(commit=False)
    comment.author = self.request.user  # 直接给comment实例赋值作者
    comment.article = self.object
    comment.save()
    return super().form_valid(form)

3. 强制用户登录才能提交评论（可选） #

为了避免匿名用户提交评论导致self.request.user为匿名用户，给视图添加LoginRequiredMixin：

from django.contrib.auth.mixins import LoginRequiredMixin

class CommentPost(LoginRequiredMixin, SingleObjectMixin, FormView):
    # 原有代码...

说明 #

• 移除表单中的author字段后，页面上不会再显示作者选择框，避免用户输入覆盖后台自动赋值。
• 修正form_valid方法后，确保评论实例的作者被正确设置为当前登录用户。
• 添加LoginRequiredMixin可确保只有登录用户才能访问评论提交功能，避免出现匿名用户提交时的错误。

内容的提问来源于stack exchange，提问作者Luca