Question

Rails 5，我试图从零开始添加Likes，而没有gem依赖项。我非常想把它放下来，但是被评论加入时所发生的一切完全迷住了。

存储和保存article.likes效果很好。然后我得到了评论。喜欢工作。现在，当我喜欢一条评论时，他们会分别存储一个新的“赞”（太好了！），但是现在Article不能正确保存任何喜欢，甚至更奇怪：article.likes.count给出了评论的全部赞总数。我确信这是一个简单的解决方法，但我完全不了解它，并且我已经尝试了所有方法。为此，我已经钻了一些深的兔子洞。

我认为问题出在路由或模型之间的关系上。

文章有很多评论，而且都有很多赞。这是从like.rb开始的模型：

 class Like < ApplicationRecord
   belongs_to :user
   belongs_to :article
   belongs_to :comment

   # Make sure that one user can only have one like per post or comment
   validates :user_id, uniqueness: { scope: [:article_id, :comment_id] }

 end

article.rb

class Article < ApplicationRecord

  belongs_to :user

  ...

  # destroy associated comments on article deletion
  has_many :comments, dependent: :destroy

  has_many :likes, dependent: :destroy

end

comment.rb

class Comment < ApplicationRecord
  belongs_to :article
  belongs_to :user

  ...

  has_many :likes, dependent: :destroy

end

routes.rb

  ...
  resources :articles, :path => 'blog' do
    resources :likes, only: [:create, :destroy]

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

  end

多肉的likes_controller.rb。注意＃{}，一切都会检查应该采用的方式，那么为什么comment.likes.create可以正确保存，而article.likes.create却不能保存？请帮助。

class LikesController < ApplicationController
  before_action :get_signed_in_user
  before_action :comment_or_article

  def create
    if @comment_like
      like_resource(comment)
    else
      like_resource(article)
    end
  end

  def destroy
    if @comment_like
      comment.likes.where(user: current_user).destroy_all
    else
      article.likes.where(user: current_user).destroy_all
    end
    flash[:success] = "Unliked! :("
    redirect_to article_redirect(article)
  end

  private
  def like_resource(obj)
    if obj.likes.where(user: current_user.id).present?
      flash[:error] = "You've already upvoted this! + #{like_params} + #{@comment_like} + #{obj}"
    if @comment_like
      if obj.likes.create(user: current_user, article: @article)
        flash[:success] = "Upvoted Comment! + #{like_params} + #{@comment_like} + #{obj}"
      else
          flash[:error] = "An error prevented you from upvoting."
      end
    elsif obj.likes.create(user: current_user)
      flash[:success] = "Upvoted Blog! + #{like_params} + #{@comment_like} + #{obj}"
    else
      flash[:error] = "An error prevented you from upvoting."
    end
    redirect_to article_path(article)
  end

  def get_signed_in_user
    unless user_signed_in?
      flash[:error] = "Sign in to upvote!"
      redirect_back(fallback_location: articles_path)
    end
  end

  # decide what we are liking
  def comment_or_article
    if comment
      @comment_like = true
    else
      @comment_like = false
    end
  end

  def article
    @article = Article.find(params[:article_id])
  end

  def comment
    unless params[:comment_id].nil?
      @comment = article.comments.find(params[:comment_id])
    end
  end

  def like_params
    params.permit( :article_id, :comment_id).merge(user_id: current_user.id)
  end
end

最后，在我的article / show.html.erb中，点击类似按钮：

<%= link_to "Like", article_likes_path(@article), method: :post %>
<%= "#{@article.likes.count}" %>

... # inside loop to show comments:
<%= link_to "Like", article_comment_likes_path(@article, comment), method: :post %>
<%= "#{comment.likes.count}" %>

TLDR：评论喜欢做得很好，可以保存，单独计算也可以。文章喜欢不会保存，但article.likes.count === article.comments.likes.count。为什么？我希望article.likes完全独特，就像它自己的评论一样。

谢谢。

编辑：在like.rb中取出belongs_to :comments，并将like_controller.rb主函数重构为

 private
  def like_resource(obj)
    if obj.likes.where(user: current_user.id).present?
      flash[:error] = "You've already upvoted this!"
    elsif obj.likes.create(user: current_user, article: @article)
      flash[:success] = "Upvoted!"
    else
      flash[:error] = "An error prevented you from upvoting."
    end
    redirect_to article_path(article)
  end

喜欢发表评论时，始终提供@article会有所帮助。像这样的文章将不需要comment_id来保存。

很抱歉，很长的帖子，希望对您有所帮助。

Answer 1

实际上，我才知道。

class Like < ApplicationRecord
  belongs_to :user
  belongs_to :article
  # belongs_to :comment
end

注释掉上面的内容，它允许@article“ like”保存而不引用任何注释。喜欢的文章会正确保存。但是，只要喜欢article.comment，article.likes.count仍会增加。这意味着article.likes始终> = article.comments.likes;完全可以。

我刚刚将@ article.likes更改为：

  <%= "#{@article.likes.where(comment_id: nil).count}" %>

过滤掉所有严格的article.likes。评论。喜欢仍然可以正常工作。

Rails 5在文章和评论中添加喜欢

1 个答案: