遵循 Michael Hartl 的 Rails 教程中的功能

Question

我正在尝试实现 Hartl 的 RoR 教程第 12 章中的追随者功能。

我有一个功能，我可以登录，转到另一个用户个人资料，单击关注，（刷新页面后）我看到我现在正在关注他们。与取消关注相同。

但是，我的集成测试失败，Ajax 无法工作，当我单击关注或取消关注时，我的 Rails 服务器日志中出现此错误：

Rendered users/_follow.html.erb (1.7ms)
Rendered relationships/destroy.js.erb (2.5ms)
Completed 500 Internal Server Error in 17ms
NoMethodError - undefined method `id' for nil:NilClass:

我的代码完全符合 Hartl 的（我认为）。但是，我在我的用户模型和设计上使用 FriendlyID，其中之一（可能是 FriendlyID）会导致问题。

我相信这是所有相关的代码。

任何想法都将不胜感激......现在在第 5 小时左右！

controllers/users_controller.rb

def following
@title = "Following"
@user  = User.friendly.find(params[:id])
@users = @user.following
render 'show_follow'
end

def followers
@title = "Followers"
@user  = User.friendly.find(params[:id])
@users = @user.followers
render 'show_follow'
end

controllers/relationships_controller.rb

def create
user = User.friendly.find(params[:followed_id])
current_user.follow(user)
respond_to do |format|
  format.html { redirect_to @user }
  format.js
 end
end

def destroy
user = Relationship.find(params[:id]).followed
current_user.unfollow(user)
respond_to do |format|
  format.html { redirect_to @user }
  format.js
end
end

models/user.rb

# follows a user
def follow(other_user)
active_relationships.create(followed_id: other_user.id)
end

# unfollows a user
def unfollow(other_user)
  active_relationships.find_by(followed_id: other_user.id).destroy
end

# returns true if user is following the other user
def following?(other_user)
following.include?(other_user)
end

_unfollow.html.erb

<%= form_for(current_user.active_relationships.find_by(followed_id: @user.id), 
html: { method: :delete }, remote: true) do |f| %>  
<%= f.submit "Unfollow", class: "btn" %>
<% end %>

_follow.html.erb

<%= form_for(current_user.active_relationships.build(followed_id: @user.id), remote: true) do |f| %>
<div><%= hidden_field_tag :followed_id, @user.id %></div>
<%= f.submit "Follow", class: "btn" %>
<% end %>

Answer 1

在您的 relationships_controller.rb 中，您尚未定义 @user 变量，这就是您收到 undefined method 错误的原因。试试这个：

def create
  @user = User.friendly.find(params[:followed_id])
  current_user.follow(@user)
  respond_to do |format|
    format.html { redirect_to @user }
    format.js
  end
end

def destroy
  @user = Relationship.find(params[:id]).followed
  current_user.unfollow(@user)
  respond_to do |format|
    format.html { redirect_to @user }
    format.js
  end
end