【问题标题】：How to delete a comment that is nested inside of a post, which is nested inside of a topic?如何删除嵌套在帖子内的评论，该评论嵌套在主题内？
【发布时间】：2014-12-05 03:19:42
【问题描述】：

我正在尝试删除嵌套在帖子中的评论。所述帖子嵌套在主题内。我对 RoR 还很陌生，在提出问题之前尝试自己做一些事情，在这里真的需要帮助。我当前的设置删除了整个帖子而不是评论

routes.rb

Rails.application.routes.draw do

  devise_for :users

  resources :users, only: [:update]

  resources :topics do
    resources :posts, except: [:index]
  end

  resources :posts, only: [] do
    resources :comments, only: [:create, :destroy]
  end
end

（模型）topic.rb

class Topic < ActiveRecord::Base
 has_many :posts, dependent: :destroy
end

（模型）post.rb

class Post < ActiveRecord::Base
 has_many :comments, dependent: :destroy
 belongs_to :user
 belongs_to :topic
end

（模型）comment.rb

class Comment < ActiveRecord::Base
 belongs_to :post
 belongs_to :user
end

comment_controller

def destroy
  @topic = Topic.find(params[:topic_id])
  @post = Post.find(params[:post_id])
  @comment = @post.comments.find(params[:id])

 authorize @comment
  if @comment.destroy
   flash[:notice] = "Comment was removed"
   redirect_to [@post.post, @post]
  else
   flash[:notice] = "There was an error removing comment"
   redirect_to [@topic, @post]
  end
end

部分正在视图/帖子/节目中呈现

link_to "Delete", [@topic, @post], method: :delete, data: {confirm: "Are you sure you want to delete this ?"}

【问题讨论】：

标签： ruby-on-rails nested

【解决方案1】：

你应该改变这个

link_to "Delete", [@topic, @post], method: :delete, data: {confirm: "Are you sure you want to delete this ?"}

到这里

link_to "Delete", [@post, @comment], method: :delete, data: {confirm: "Are you sure you want to delete this ?"}

因此，该链接为您提供了一条带有 DELETE http 方法的类似 posts/:post_id/cmets/:id 的路径。

以及 cmets 的控制器：

def destroy
  @topic = Topic.find(params[:topic_id])
  @post = Post.find(params[:post_id])
  @comment = @post.comments.find(params[:id])

  authorize @comment
  if @comment.destroy
    flash[:notice] = "Comment was removed"
    redirect_to @post
  else
    flash[:notice] = "There was an error removing comment"
    redirect_to [@topic, @post]
  end
end

我刚刚更改了第一个redirect_to，因为我不知道你为什么要使用redirect_to [@post.post, @post]

【讨论】：

【解决方案2】：

在视图/帖子/节目上呈现的部分我希望删除整个帖子。

如果有 cmets 视图，您可能会显示类似这样的内容，并将路线更新为您的路线，我猜了一下：

link_to 'Delete', post_comment_path(@post, @comment), method: :delete, data: { confirm: 'Are you sure?' }

或者，如果您有 cmets 的索引视图，这可能会起作用：

link_to 'Delete', comment, method: :delete, data: { confirm: 'Are you sure?' }

此外，Rails 指南的这一部分可能会有所帮助：http://guides.rubyonrails.org/routing.html#nested-resources

祝你好运！