Question

我正在处理添加到收藏夹功能，用户点击链接并向他的收藏夹添加资源，然后再次点击以删除它。问题是无论我对我的代码做什么，Rails都会继续喜欢除了我正在寻找的问题之外的任何东西

免责声明：在我的代码中，我拼错了最喜欢的字，请原谅我

Controller

class FavoritesController < ApplicationController  
  def favor
    @question = Question.find_by(params[:id])
    @favorite = Favorite.new

    @favorite.user = current_user
    @favorite.question = @question

    @favorite.save

    redirect_to :back
  end

  def unfavor
    @question = Question.find_by(params[:id])

    @favorite = current_user.favorites.find_by(question_id: @question)
    @favorite.destroy
    redirect_to :back
  end
end

路由

concern :favoriteable do
  post 'favorites/favor',   to:   'favorites#favor',    as: :favor
  post 'favorites/unfavor', to:   'favorites#unfavor',  as: :unfavor
end

resources :questions, concerns: [:commentable, :favoriteable] do
  resources :answers
end

问题＃节目

span 
  - if current_user.favorites.exists?(question_id: @question)
    = link_to 'Unfav this', question_unfavor_path(@question), method: :post
  - else    
    = link_to 'Fav this', question_favor_path(@question), method: :post

记录（注意33如何变为15 ）

Started POST "/questions/33/favorites/favor" for 127.0.0.1 at 2014-07-01 19:10:02 +0400
Processing by FavoritesController#favor as HTML
  Parameters: {"authenticity_token"=>"SjOLDdIx4DMfHwLJLBdNd6N12tLNyN+QdaMT0OlpOCU=", "question_id"=>"33"}
  Question Load (0.7ms)  SELECT  "questions".* FROM "questions"  LIMIT 1
  User Load (0.1ms)  SELECT  "users".* FROM "users"  WHERE "users"."id" = $1 LIMIT 1  [["id", 11]]
   (0.1ms)  BEGIN
  SQL (0.3ms)  INSERT INTO "favorites" ("created_at", "question_id", "updated_at", "user_id") VALUES ($1, $2, $3, $4) RETURNING "id"  [["created_at", "2014-07-01 15:10:02.490036"], ["question_id", 15], ["updated_at", "2014-07-01 15:10:02.490036"], ["user_id", 11]]
   (1.0ms)  COMMIT
Redirected to http://localhost:3000/questions/33

无法弄清楚，请帮忙！

Answer 1

find_by与Question.find_by(id: params[:id])等属性一起使用。您使用不正确，即未指定属性名称。

当你这样做时

@question = Question.find_by(params[:id]) ## in "favor" and "unfavor" actions

它等同于做

@question = Question.find_by(nil)

nil的原因：请注意服务器日志中生成的params哈希值，您收到params[:question_id]而非params[:id]。因此，params[:id]是nil。

因此，形成的查询类似于：

SELECT  "questions".* FROM "questions" LIMIT 1

最有可能返回questions表中的第一条记录。这就是您使用id = 15获得相同问题记录的原因。

要解决此问题，您需要使用以下内容更新favor和unfavor操作：

@question = Question.find(params[:question_id]) ## Using "find" which searches a record based on "id" attribute

-OR -

@question = Question.find_by(id: params[:question_id]) ## Using "find_by" and specifying "id" attribute

我建议您使用第一个选项，即find作为基于id（主键）搜索时获取结果的更加语义的方法

Answer 2

您的参数正在发布:question_id而不是:id

在视图中切换到此

- if current_user.favorites.exists?(question_id: @question)
    = link_to 'Unfav this', question_unfavor_path(id: @question.id), method: :post
- else    
    = link_to 'Fav this', question_favor_path(id: @question.id), method: :post

或者在你的控制器中切换到这个（这在我看来更干净）

@question = Question.find(params[:question_id])

Rails params [：id]保持返回相同的id

2 个答案: