Question

我不明白为什么开发中的某些东西有效，但在生产中它有不同的行为，这里是other example。在此示例中，评论始终由DESC在开发中排序，但在生产中如果用户喜欢评论，那么该评论将移动到列表的底部，就像重新创建评论一样。

为什么会这样？

comments_controller

class CommentsController < ApplicationController
  before_action :set_commentable, only: [:index, :new, :create]
  before_action :set_comment, only: [:edit, :update, :destroy]
  before_action :correct_user, only: [:edit, :update, :destroy]

  def index
    @comments = @commentable.comments.order("created_at DESC")
  end

  def new
    @comment = @commentable.comments.new
  end

  def create
    @comment = @commentable.comments.new(comment_params)
    if @comment.save
      redirect_to @commentable, notice: "Comment created."
    else
      render :new
    end
  end

  def edit
  end

  def update
    if @comment.update_attributes(comment_params)
      redirect_to :back, notice: "Comment was updated."
    else
      render :edit
    end
  end

  def destroy
    @comment.destroy
    redirect_to @comment.commentable, notice: "Comment destroyed."
  end

  def like
    @comment = Comment.find(params[:id])
    @comment_like = current_user.comment_likes.build(comment: @comment)
    if @comment_like.save
      @comment.increment!(:likes)
      flash[:success] = 'Thanks for liking!'
    else
      flash[:error] = 'Too many likes'
    end  
    redirect_to(:back)
  end

  private

  def set_commentable
    @commentable = find_commentable
  end

  def set_comment
    @comment = current_user.comments.find(params[:id])
  end

  def correct_user
    @comment = current_user.comments.find_by(id: params[:id])
    redirect_to root_url, notice: "Not authorized to edit this comment" if @comment.nil?
  end

  def find_commentable
    if params[:goal_id]
      Goal.find(params[:goal_id])
    elsif params[:habit_id]
      Habit.find(params[:habit_id])
    elsif params[:valuation_id]
      Valuation.find(params[:valuation_id])
    elsif params[:stat_id]
      Stat.find(params[:stat_id])
    end
  end

  def comment_params
    params[:comment][:user_id] = current_user.id
    params.require(:comment).permit(:content, :commentable, :user_id, :like)
  end
end

comment_like.rb

class CommentLike < ActiveRecord::Base
  belongs_to :user
  belongs_to :comment
  belongs_to :habit
  belongs_to :stat
  belongs_to :valuation
  belongs_to :goal
  validates :user, uniqueness: { scope: :comment }
  belongs_to :liker, class_name: 'User', foreign_key: :user_id
  belongs_to :liked_comment, class_name: 'Comment', foreign_key: :comment_id
end

comment.rb

class Comment < ActiveRecord::Base
    after_save :create_notification
  has_many :notifications
  has_many :comment_likes   
  has_many :likers, through: :comment_likes, class_name: 'User', source: :liker
  belongs_to :habit
  belongs_to :stat
  belongs_to :valuation
  belongs_to :goal
    belongs_to :user
  validates :user, presence: true

private

  def create_notification
    author = 
      if goal
        goal.user
      #elsif comment_like
      # comment_like.user
      elsif habit
       habit.user
      elsif stat
        stat.user
      elsif valuation
        valuation.user
      end
    notifications.create(
      comment:      self,
      likes:        likes,
      habit:        habit,
      stat:         stat,
      goal:         goal,
      valuation:    valuation,
      user:         author,      
      read:         false
    )
  end
end

模式

  create_table "comment_likes", force: true do |t|
    t.integer  "user_id"
    t.integer  "comment_id"
    t.datetime "created_at", null: false
    t.datetime "updated_at", null: false
  end

  create_table "comments", force: true do |t|
    t.text     "content"
    t.integer  "goal_id"
    t.integer  "habit_id"
    t.integer  "valuation_id"
    t.integer  "stat_id"
    t.integer  "commentable_id"
    t.string   "commentable_type"
    t.integer  "user_id"
    t.datetime "created_at",       null: false
    t.datetime "updated_at",       null: false
    t.integer  "likes"
  end

  add_index "comments", ["commentable_id", "commentable_type"], name: "index_comments_on_commentable_id_and_commentable_type"
  add_index "comments", ["commentable_type", "commentable_id"], name: "index_comments_on_commentable_type_and_commentable_id"
  add_index "comments", ["user_id"], name: "index_comments_on_user_id"

Answer 1

对于Rails 4.0+，您需要在Comment模型中添加范围，所以它看起来像这样：

class Comment < ActiveRecord::Base
  default_scope { order('created_at DESC') }
  ...

end

有关详情，请阅读 docs 。

如何在生产中订购DESC的评论？

1 个答案: