Ruby on rails Rails：充当标记，在尝试按标记查找文章时出错

我一直在关注RailsCasts的一个插曲，并试图使文章具有可标记性。然后我想让标签在articles show.html页面上可以点击，这样用户就可以找到其他相关的文章。我使用的是Rails 4。但是，我得到了以下错误：

ActiveRecord::RecordNotFound in ArticlesController#show

Couldn't find Article without an ID

Extracted source (around line #43):

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

然后，我尝试进行以下更改，这是我在查看RailsCast代码后观察到的：

articles\u controller.rb

[...]
    def show  
        if params[:tag]
          @articles = Article.tagged_with(params[:tag])
        else
          @article = Article.find(params[:id])
        end
    end

Network::Application.routes.draw do
  resources :libraries

  get "libraries/show"
  devise_for :authors, :controllers => {:registrations => "authors/registrations"}

  get 'tags/:tag', to: 'articles#show', as: :tag 

  devise_scope :author do
    get 'signup', to: 'devise/registrations#new' 
    get 'signin', to: 'devise/sessions#new' 
    # get 'logout', to: 'devise/sessions#destroy' 
  end

  resources :relationships, only: [:create, :destroy]

  get "landing_page/index"
  # The priority is based upon order of creation: first created -> highest priority.
  # See how all your routes lay out with "rake routes".
  resources :articles do
    resources :comments
  end
  # You can have the root of your site routed with "root"
  root 'landing_page#index'
  get '/:id', to: 'libraries#show'
end

 class Article < ActiveRecord::Base
    has_many :comments, dependent: :destroy
    belongs_to :author 
    acts_as_taggable
    acts_as_taggable_on :tag_list

    validates :title, presence: true,
                    length: { minimum: 5 }
  validates :text, presence: true,
                                 length: { minimum: 2 }
    validates :article_start, presence: true,
                                        length: {minimum: 10}

end

class CreateArticles < ActiveRecord::Migration
  def change
    create_table :articles do |t|
      t.string :title
      t.time :era
      t.string :chapter
      t.date :article_start
      t.text :text
      t.string :tag_list

      t.timestamps
    end
  end
end

在工作显示页面上单击标记时出现错误：

NoMethodError in Articles#show
undefined method 'title' for nil:NilClass

<div id="article-title">
  <h1>
   <p>
    <%= @article.title %></span>
   </p>
  </h1>
</div>

article.rb

[...]
    def show  
        if params[:tag]
          @articles = Article.tagged_with(params[:tag])
        else
          @article = Article.find(params[:id])
        end
    end

Network::Application.routes.draw do
  resources :libraries

  get "libraries/show"
  devise_for :authors, :controllers => {:registrations => "authors/registrations"}

  get 'tags/:tag', to: 'articles#show', as: :tag 

  devise_scope :author do
    get 'signup', to: 'devise/registrations#new' 
    get 'signin', to: 'devise/sessions#new' 
    # get 'logout', to: 'devise/sessions#destroy' 
  end

  resources :relationships, only: [:create, :destroy]

  get "landing_page/index"
  # The priority is based upon order of creation: first created -> highest priority.
  # See how all your routes lay out with "rake routes".
  resources :articles do
    resources :comments
  end
  # You can have the root of your site routed with "root"
  root 'landing_page#index'
  get '/:id', to: 'libraries#show'
end

 class Article < ActiveRecord::Base
    has_many :comments, dependent: :destroy
    belongs_to :author 
    acts_as_taggable
    acts_as_taggable_on :tag_list

    validates :title, presence: true,
                    length: { minimum: 5 }
  validates :text, presence: true,
                                 length: { minimum: 2 }
    validates :article_start, presence: true,
                                        length: {minimum: 10}

end

class CreateArticles < ActiveRecord::Migration
  def change
    create_table :articles do |t|
      t.string :title
      t.time :era
      t.string :chapter
      t.date :article_start
      t.text :text
      t.string :tag_list

      t.timestamps
    end
  end
end

---

更新

ArticlesController

actions

show

和

index

，如下所示：

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

   def index  
     if params[:tag]
       @articles = Article.tagged_with(params[:tag])
     else
       @articles = Article.all
     end
   end

另外，更新

routes.rb

：

更换

 get 'tags/:tag', to: 'articles#show', as: :tag

与

 get 'tags/:tag', to: 'articles#index', as: :tag ## It should go to index action not show

---

嗨，Kirti，我仍然得到nil:NilClass的

未定义的方法'title'。应用程序没有以某种方式说明它对修复的想法。任何其他建议都非常感谢！你能分享问题中的stacktrace吗？我更新了帖子。我的选择是完整的、框架的和应用的。如果还需要，请告诉我。谢谢分享。你觉得表演怎么样？分享相关代码或查看我的更新答案，例如，我将如何通过我的应用程序调用它。你是说，当你说call时，my show.html中的
？我不知道你指的是什么文件，除了控制器。我将同时更新def show。