如何在 Rails 控制台中显示带有换行符的实例的值答案

【问题标题】：How to show values of a instance with line break in Rails console如何在 Rails 控制台中显示带有换行符的实例的值
【发布时间】：2014-10-22 16:55:22
【问题描述】：

我开始在 Rails 控制台中使用pry。当我获得 Rails 模型的实例时，显示的值不带换行符，如下所示：

pry(#<Class:0x1022f60e0>):1> first
=> #<Article id: 1, name: "What is Music", content: "Music is an art form in which the medium is sound o...", created_at: "2011-08-24 20:35:29", updated_at: "2011-08-24 20:37:22", published_at: "2011-05-13 23:00:00">

来自http://railscasts.com/episodes/280-pry-with-rails?view=asciicast

有没有办法用这样的换行符显示值？

Article
 id: 1
 name: "What is Music"
 content: "Music is an art form in which the medium is sound o..."
 created_at: "2011-08-24 20:35:29"
 updated_at: "2011-08-24 20:37:22"
 published_at: "2011-05-13 23:00:00"

【问题讨论】：

你试过.to_yaml吗？

标签： ruby-on-rails ruby rails-console pry

【解决方案1】：

您可以在模型实例上调用 .to_yaml！它返回一个字符串，其格式几乎与您要求的完全一样。

以下是 to_yaml 输出的一些示例：

http://yaml4r.sourceforge.net/doc/page/examples.htm

【讨论】：

【解决方案2】：

我建议您安装awesome_print。

将其添加到您的Gemfile：

group :development do
  gem 'awesome_print'
end

并使用bundle install 安装它。

现在使用ap在控制台打印：

pry(#<Class:0x1022f60e0>):1> ap first

#<Article:0x1022f60e0> {
           :id => 1,
         :name => "What is Music"
      :content => "Music is an art form in which the medium is sound o..."
   :created_at => "2011-08-24 20:35:29"
   :updated_at => "2011-08-24 20:37:22"
 :published_at => "2011-05-13 23:00:00"
}

【讨论】：

【解决方案3】：

我认为，下面的技巧对你有用。

arup@linux-wzza:~/Rails/model_prac> rails c
Loading development environment (Rails 4.1.4)
2.1.2 :001 > Comment.first
  Comment Load (0.4ms)  SELECT  "comments".* FROM "comments"   ORDER BY "comments"."id" ASC LIMIT 1
 => #<Comment id: 1, value_old: "I am a good Boy.", value_new: "I am a bad Boy.", created_at: "2014-08-02 17:36:14", updated_at: "2014-08-02 18:21:42">
2.1.2 :002 > y Comment.first
  Comment Load (0.4ms)  SELECT  "comments".* FROM "comments"   ORDER BY "comments"."id" ASC LIMIT 1
--- !ruby/object:Comment
attributes:
  id: 1
  value_old: I am a good Boy.
  value_new: I am a bad Boy.
  created_at: 2014-08-02 17:36:14.249466000 Z
  updated_at: 2014-08-02 18:21:42.511522000 Z
 => nil
2.1.2 :003 >

【讨论】：