ruby-on-rails - Rails 用户 has_many posts, has_many favorite_posts

Question

首先对英语感到抱歉

所以我已经有了“用户 - 帖子”一对多关联，这意味着每个帖子只能有一个作者，现在我想在用户个人资料中添加“最喜欢的帖子”按钮，以及“添加到收藏夹”按钮每个帖子，所以问题是如何实现这种正确的方式？我应该修改我的用户 - 发布关联吗？或创建其他模型？我，有点糊涂。提前致谢!

其实我想要这个结果:

@user.posts #返回该用户创建的所有帖子

@user.favorite_posts #返回该用户添加到收藏夹的帖子

这是我的用户模型:

class User < ApplicationRecord

  mount_uploader :avatar, ImageUploader
  validates :username, presence: true, uniqueness: true, length: {in: 3..20}

  devise :database_authenticatable, :registerable,
     :recoverable, :rememberable, :validatable

  has_many :posts, dependent: :destroy
  has_many :comments, dependent: :destroy
  has_many :ratings
  enum role: [ :user, :admin ]

  def calculate_average
    ratings.blank? ? 0 : ratings.map(&:value).inject(:+) / ratings.count.to_f
  end
end

帖子模型:

class Post < ApplicationRecord
  mount_uploader :image, ImageUploader
  validates :body, presence: true
  validates :title, presence: true, length: { maximum: 50}

  belongs_to :user
  has_many :comments, dependent: :destroy
end

编辑

好吧，看看我是怎么做到的，它完全按照我想要的方式工作。

这是我的用户模型:

class User < ApplicationRecord

  mount_uploader :avatar, ImageUploader
  validates :username, presence: true, uniqueness: true, length: {in: 3..20}

  devise :database_authenticatable, :registerable,
     :recoverable, :rememberable, :validatable

  has_many :posts, dependent: :destroy
  has_many :comments, dependent: :destroy
  has_many :ratings
  has_many :favorites, dependent: :destroy
  has_many :favorite_posts, through: :favorites, source: "post"
  enum role: [ :user, :admin ]

  def calculate_average
    ratings.blank? ? 0 : ratings.map(&:value).inject(:+) / ratings.count.to_f
  end
end

Answer 1

你需要many-to-many最喜欢的帖子的关系，首先运行这个命令来创建一个表 favorite_posts

rails g model FavoritePost user:references post:references

然后

rails db:migrate

然后将这些添加到您的模型中，如下所示:

#=> model/user.rb
class User < ApplicationRecord
    has_many :favorite_posts, dependent: :destroy # or you can use only this line except second if you will face any problem
    has_many :posts, through: :favorite_posts
end

#=> model/post.rb
class Post < ApplicationRecord
    has_many :favorite_posts, dependent: :destroy
    has_many :users, through: :favorite_posts
end

#=> model/favorite_post.rb
class FavoritePost < ApplicationRecord
  belongs_to :user
  belongs_to :post
end

那是关系部分，现在创建一个最喜欢的帖子部分。对于新代码，您可以创建一个 Controller ，即

rails g controller favorites

然后是你的路由文件:

resources :favorites

使用 rake routes 的新路由示例:

    favorites GET    /favorites(.:format)          favorites#index
              POST   /favorites(.:format)          favorites#create
 new_favorite GET    /favorites/new(.:format)      favorites#new
edit_favorite GET    /favorites/:id/edit(.:format) favorites#edit
     favorite GET    /favorites/:id(.:format)      favorites#show
              PATCH  /favorites/:id(.:format)      favorites#update
              PUT    /favorites/:id(.:format)      favorites#update
              DELETE /favorites/:id(.:format)      favorites#destroy

在你的 View 文件中添加如下内容:

# For creating favorite
<%= link_to "Favorite", favorites_path(user: current_user, post: post.id), class: 'btn bf-save-btn', method: :post, data: {disable_with: "Saving..."}, title: "Add to favorite" %>

# For deleting favorite list
<%= link_to "Unfavorite", favorite_path(post.id), class: 'btn af-save-btn', method: :delete, data: {disable_with: "Removing...."}, title: "Remove from favorite" %>

在 favorites_controller.rb 中:

def index
    @saves = current_user.favorite_post
end
# index.html.erb
<% @saves.each do |fav| %>
     <%= link_to fav.post.post_title, post_path(fav.post) %>
<% end %>

def create
    @save = FavoritePost.new(post_id: params[:post], user: current_user)

    respond_to do |format|
        if @save.save
            flash[:success] = 'Saved'
            format.html { redirect_to request.referer }
            format.xml  { render :xml => @save, :status => :created, :location => @save }
        else
            format.html { redirect_to request.referer }
            format.xml  { render :xml => @save.errors, :status => :unprocessable_entity }
        end
    end
end

def destroy
    post = Post.find(params[:id])
    @save = FavoritePost.where(user_id: current_user.id, post_id: post.id).first

    respond_to do |format|
        if @save.destroy
            flash[:error] = 'Unsaved'
            format.html { redirect_to request.referer, status: 303  }
            format.js { redirect_to request.referer, status: 303  }
            # format.xml  { head :ok }
        end
    end
end

这就是最喜欢/最不喜欢的功能。现在您需要为何时显示 Favorite 以及何时显示 Unfavorite 创建一些逻辑。

因为这个要求有很多种方式，首先你需要了解这个然后你可以随心所欲。

此外，要在不重新加载页面的情况下实现此目的，您可以尝试一些 Ajax。

更新

class User < ApplicationRecord

    mount_uploader :avatar, ImageUploader
    validates :username, presence: true, uniqueness: true, length: {in: 3..20}

    devise :database_authenticatable, :registerable,
     :recoverable, :rememberable, :validatable

    has_many :posts, dependent: :destroy
    has_many :comments, dependent: :destroy
    has_many :ratings

    # Newly added
    has_many :favorite_posts, dependent: :destroy # or you can use only this line except second if you will face any problem
    has_many :posts, through: :favorite_posts

    enum role: [ :user, :admin ]

    def calculate_average
        ratings.blank? ? 0 : ratings.map(&:value).inject(:+) / ratings.count.to_f
    end
end

希望对您有所帮助。