在django上添加好友系统

Question

我一直在尝试添加朋友系统，用户可以在其中添加和删除朋友（其他用户），在完成代码后，我发现当登录用户尝试从其他用户的个人资料中添加朋友时出现错误，添加朋友按钮重定向到登录的用户配置文件，使其无法添加新朋友，它可以将自己添加为朋友。我个人认为错误出在 views.py 个人资料视图上。

views.py（profile 显示用户的个人资料，change_friend 是添加和删除朋友的那个）

    def profile(request, username=None):
        friend = Friend.objects.filter(current_user=request.user).first()
        friends = []
        if friend:   
          friends = friend.users.all()
        if username:
          post_owner = get_object_or_404(User, username=username)
          user_posts=Post.objects.filter(user_id=post_owner)
        else:
          post_owner = request.user
          user_posts=Post.objects.filter(user=request.user)
        args1 = {
            'post_owner': post_owner,
            'user_posts': user_posts,
            'friends': friends,
        }
        return render(request, 'profile.html', args1)

    def change_friends(request, operation, pk):
        friend = User.objects.get(pk=pk)
        if operation == 'add':
          Friend.make_friend(request.user, friend)
        elif operation == 'remove':
          Friend.lose_friend(request.user, friend)
        return redirect('profile')

模型.py

    class Friend(models.Model):
        users = models.ManyToManyField(User, default='users', blank=True, related_name='users')
        current_user = models.ForeignKey(User, related_name='owner', on_delete=models.CASCADE, null=True)

        @classmethod
        def make_friend(cls, current_user, new_friend):
            friend, created = cls.objects.get_or_create(
                current_user=current_user
            )
            friend.users.add(new_friend)

        @classmethod
        def lose_friend(cls, current_user, new_friend):
            friend, created = cls.objects.get_or_create(
                current_user=current_user
            )
            friend.users.remove(new_friend)

profile.html

    <div class="media">
      <div class="media-body">
        <h2 class="account-heading">{{ post_owner.username }}</h2>
        <p class="text-secondary">{{ post_owner.email }}</p>
        {% if not user in friends %}
          <a href="{% url 'change_friends' operation='add' pk=user.pk %}">
            <button type="button">add Friend</button>
          </a>
        {% endif %}
      </div>
    </div>
    <div>
      <h2>Friends</h2>
      {% for friend in friends %}
        <p>{{ friend.username }}</p>
        <a href="{% url 'change_friends' operation='remove' pk=friend.pk %}">
          <button type="button">Remove Friend</button>
        </a>
      {% endfor %}
    </div>

urls.py

    urlpatterns = [
        path('profile/<str:username>/', views.profile, name='profile_pk'),
        url(r'^connect/(?P<operation>.+)/(?P<pk>\d+)/$', views.change_friends, name='change_friends'),
    ]

Answer 1

问题是您通过user 对象将request.user 对象传递给change_friends 视图。在模板中使用时默认为user == request.user。

只需将您在 profile.html 中的那一行更改为：

<a href="{% url 'change_friends' operation='add' pk=post_owner.pk %}">
    <button type="button">add Friend</button>
</a>

现在，我注意到，一旦用户添加了新朋友，您就会将用户重定向到 profile 视图，这不是您想要的。这是因为当您在change_friends 视图中调用redirect() 函数时，您没有将任何参数传递给profile 视图。你定义的用户名应该是None，然后你说if not username然后post_owner应该是request.user

如何改变这个？好吧，只需在调用 redirect 作为关键字参数时传递所需的 username。如下：

return redirect('profile', username=friend.username)

Answer 2

在您看来，好友地址是已经添加的好友，您希望获得有资格添加为好友的用户到 request.user 对象。为此，

在您的个人资料视图中：

def profile(request, username=None):
    friend = Friend.objects.filter(current_user=request.user).first()
    friends = []
    # In case of friend is None, I send all users except request user, to be able to add on html template.
    friends_to_add = User.objects.exclude(id=request.user.id)
    if friend:   
        friends = friend.users.all()
        # here we have a valid friend (who is the user request has)
        # so I don't want to send users to template who are already friend of request user.
        friends_to_add = friends_to_add.exclude(id__in=friend.users.values_list("id"))
    if username:
        post_owner = get_object_or_404(User, username=username)
        user_posts=Post.objects.filter(user_id=post_owner)
    else:
        post_owner = request.user
        user_posts=Post.objects.filter(user=request.user)
    args1 = {
        'post_owner': post_owner,
        'user_posts': user_posts,
        'friends': friends,
        'friends_to_add': friends_to_add,
    }
    return render(request, 'profile.html', args1)

在您的模板文件中，您可以将它们用作：

<div class="media">
     <div class="media-body">
        <h2 class="account-heading">{{ post_owner.username }}</h2>
        <p class="text-secondary">{{ post_owner.email }}</p>
        {% for user in friends_to_add %}
            <a href="{% url 'change_friends' operation='add' pk=user.pk %}">
                <button type="button">add Friend</button>
            </a>
        {% endfor %}
    </div>
</div>

我希望这对你有意义。如果您需要，可以从 cmets 向我提出任何您无法理解的问题。