闪烁消息不成功'create'未呈现喜欢/不喜欢的功能

Question

我有喜欢和不喜欢的按钮正在工作，但多次投票的错误消息不是。

用户可以投票的对象类型称为课程。我在课程索引页面上列出了所有课程及其喜欢/不喜欢按钮。我正在尝试这样做，因此如果您尝试两次喜欢或不喜欢相同的课程对象，页面会呈现一条闪光消息，通知您只能投票一次。

这是喜欢的控制器。

#likeables_controller.rb
class LikeablesController < ApplicationController
  before_action :logged_in_user
  def create
    course = Course.find(params[:liked_id])
    count = course.likers.count
    current_user.like(course)
    new_count = course.likers.count
    if new_count > count
      redirect_to courses_url
    else
      # This isn't working
      flash[:danger] = "You can only vote on a course once!"
      redirect_to courses_url
    end
  end
  def destroy
    like = Likeable.find(params[:id])
    like.destroy
    redirect_to courses_url
  end
end

我的课程索引使课程部分呈现如下：

 # index.html.erb
<%= render @courses %>

课程部分依次呈现喜欢和不喜欢按钮

# _course.html.erb
<ul class="stats">
   <li>
      <%= render partial: 'dislike', locals: {course: course} %>
    </li>
    <li>
      <%= render partial: 'like', locals: {course: course} %>
    </li>
 </ul>
 # _like.html.erb
<%= form_for(current_user.likeables.build, remote: true) do |f| %>
  <div><%= hidden_field_tag :liked_id, course.id %></div>
  <%= button_tag type: 'submit', class: "btn" do %>
    <i class="fa fa-thumbs-o-up" aria-hidden="true"></i> 
    <span id="likers"><%= course.likers.count %></span>
  <% end %>
<% end %>

如果需要，以下是我的模型和架构的相关部分：

create_table "dislikeables", force: :cascade do |t|
    t.integer  "disliker_id"
    t.integer  "disliked_id"
    t.datetime "created_at",  null: false
    t.datetime "updated_at",  null: false
    t.index ["disliked_id"], name: "index_dislikeables_on_disliked_id"
    t.index ["disliker_id", "disliked_id"], 
      name: "index_dislikeables_on_disliker_id_and_disliked_id", unique: true
    t.index ["disliker_id"], name: "index_dislikeables_on_disliker_id"
  end
  create_table "likeables", force: :cascade do |t|
    t.integer  "liker_id"
    t.integer  "liked_id"
    t.datetime "created_at", null: false
    t.datetime "updated_at", null: false
    t.index ["liked_id"], name: "index_likeables_on_liked_id"
    t.index ["liker_id", "liked_id"], 
      name: "index_likeables_on_liker_id_and_liked_id", unique: true
    t.index ["liker_id"], name: "index_likeables_on_liker_id"
  end

我的模型：

# user.rb
class User < ApplicationRecord
  # User has many courses
  has_many :courses, dependent: :destroy
  has_many :likeables, foreign_key: "liker_id",
                       dependent:   :destroy
  has_many :likes, through: :likeables, source: :liked
  has_many :dislikeables, foreign_key: "disliker_id",
                       dependent:   :destroy
  has_many :dislikes, through: :dislikeables, source: :disliked
  def like(course)
    likes << course
  end
  def dislike(course)
    dislikes << course
  end
end
# course.rb
class Course < ApplicationRecord
  has_one :user
  has_many :likeables, foreign_key: "liked_id",
                       dependent:   :destroy
  has_many :likers, through: :likeables, source: :liker
  has_many :dislikeables, foreign_key: "disliked_id",
                       dependent:   :destroy
  has_many :dislikers, through: :dislikeables, source: :disliker
  def liker?(user)
    likes.include?(user)
  end
  def disliker?(user)
    dislikes.include?(user)
  end
end
# likeable.rb
class Likeable < ApplicationRecord
  belongs_to :liked, class_name: "Course"
  belongs_to :liker, class_name: "User"
  validates :liked_id, presence: true
  validates :liker_id, presence: true
end
# dislikeable.rb
class Dislikeable < ApplicationRecord
  belongs_to :disliked, class_name: "Course"
  belongs_to :disliker, class_name: "User"
  validates :disliked_id, presence: true
  validates :disliker_id, presence: true
end

Answer 1

你的操作有问题，

def create
  like = current_user.likes.where(liked_id: params[:liked_id]).first_or_initialize
  if like.new_record? && like.save
    redirect_to courses_url
  else
    redirect_to courses_url, flash: { danger: "You can only vote on a course once!" }
  end
end

Answer 2

也许在控制器中尝试：

redirect_to courses_url, flash: { danger: "You can only vote on a course once!" }

并确保在应用程序布局中，您有 Flash 消息的渲染器。

Answer 3

试试这个

redirect_to courses_url, alert:  "You can only vote on a course once!"