ruby-on-rails - 在 View 中显示关联模型的属性

Question

我想获取在博客应用程序中创建文章的用户的用户名或电子邮件(都在用户表中)。目前我可以从 articles_controller.rb 获取用户 ID

def create
  @article = Article.new(params[:article])
  @article.user_id = current_user.id
  @article.save
  redirect_to article_path(@article)
end

但不知道如何获取相同的用户名或电子邮件。基本上我想在文章索引页面上显示用户名或电子邮件。请建议我如何完成它

用户.rb

class User < ActiveRecord::Base
    has_many :articles
    has_many :comments
  # Include default devise modules. Others available are:
  # :token_authenticatable, :confirmable,
  # :lockable, :timeoutable and :omniauthable
  devise :database_authenticatable, :registerable,
         :recoverable, :rememberable, :trackable, :validatable

  # Setup accessible (or protected) attributes for your model
  attr_accessible :username, :email, :password, :password_confirmation, :remember_me
   attr_accessible :title, :body
end

文章.rb

class Article < ActiveRecord::Base
   attr_accessible :title, :body
   has_many :comments
   belongs_to :user
end

文章 Controller .rb

class ArticlesController < ApplicationController
    def index
        @articles = Article.all
    end

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

    def new
      @article = Article.new
    end

    def create
      @article = Article.new(params[:article])
      @article.user_id = current_user.id
      @article.save
      redirect_to article_path(@article)
    end

    def destroy
      @article = Article.find(params[:id])
      @article.destroy
      redirect_to action:  'index'  
    end

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

    def update
      @article = Article.find(params[:id])
      @article.update_attributes(params[:article])
      flash.notice = "Article '#{@article.title}' Updated!"
      redirect_to article_path(@article)
     end
end

文章/index.html.erb

 <div style="color:#666666; margin-top:10px"> <%= article.created_at %></div>
     <div style="color:#666666; margin-top:10px"> <%= article.user_id %></div>

文章表

class CreateArticles < ActiveRecord::Migration
  def change
    create_table :articles do |t|
      t.string :title
      t.text  :body 
      t.timestamps
    end
    add_index :articles, [:user_id, :created_at]
  end
end

我能够在 View 中获取用户 ID，但不知道如何使用用户名或电子邮件。任何帮助将不胜感激。

Answer 1

您已经在您的 Article 模型类上定义了一个 user 关联 belongs_to :user。这将在 Article 上创建一个 user 方法，该方法返回关联的用户，因此您在 View 中:

<%= article.user.email %>

将输出关联用户的电子邮件，或者:

<%= article.user.email if article.user %>

迎合零用户值(value)。或者编写一个帮助程序以将该逻辑排除在 View 之外。