有没有办法在您的 Rails 应用程序中获取所有模型的集合? [英] Is there a way to get a collection of all the Models in your Rails app?

问题描述

有没有一种方法可以让您获得 Rails 应用中所有模型的集合?

Is there a way that you can get a collection of all of the Models in your Rails app?

基本上，我可以这样做:-

Basically, can I do the likes of: -

Models.each do |model|
  puts model.class.name
end

推荐答案

查看评论和其他答案.还有比这个更聪明的答案！或者尝试将其作为社区 wiki 进行改进.

模型不会将自己注册到主对象，所以不，Rails 没有模型列表.

Models do not register themselves to a master object, so no, Rails does not have the list of models.

但是您仍然可以查看应用程序模型目录的内容...

But you could still look in the content of the models directory of your application...

Dir.foreach("#{RAILS_ROOT}/app/models") do |model_path|
  # ...
end

另一个(疯狂的)想法是使用 Ruby 反射来搜索每个扩展 ActiveRecord::Base 的类.虽然不知道如何列出所有课程...

Another (wild) idea would be to use Ruby reflection to search for every classes that extends ActiveRecord::Base. Don't know how you can list all the classes though...

只是为了好玩，我找到了一种列出所有类的方法

Just for fun, I found a way to list all classes

Module.constants.select { |c| (eval c).is_a? Class }

终于在不查看目录的情况下成功列出了所有模型

Finally succeeded in listing all models without looking at directories

Module.constants.select do |constant_name|
  constant = eval constant_name
  if not constant.nil? and constant.is_a? Class and constant.superclass == ActiveRecord::Base
    constant
  end
end

如果你也想处理派生类，那么你需要测试整个超类链.我是通过在 Class 类中添加一个方法来实现的:

If you want to handle derived class too, then you will need to test the whole superclass chain. I did it by adding a method to the Class class:

class Class
  def extend?(klass)
    not superclass.nil? and ( superclass == klass or superclass.extend? klass )
  end
end

def models 
  Module.constants.select do |constant_name|
    constant = eval constant_name
    if not constant.nil? and constant.is_a? Class and constant.extend? ActiveRecord::Base
    constant
    end
  end
end

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