获取调用者类 [英] Get caller class

问题描述

我正在编写 Logger，但在自动添加类名时遇到了问题，我从中调用了 print_log 方法.例如这样的事情:

I'm writing Logger and got problem with automatic adding class name, from which I called print_log method. For example something like this:

class Logger
  def self.print_log(string)
    puts Time.now.strftime('%T | ') + *caller_class_name_here* + ' - ' + string 
  end
end

class MyClass
  def initialize
    Logger.print_log 'called .new() method'
  end
end

作为调用 MyClass.new 方法的结果，我想在输出中看到:

As result of calling MyClass.new method I wanna see in output:

14:41:23 |MyClass - 调用 .new() 方法

14:41:23 | MyClass - called .new() method

我确信可以使用 caller，但我还是找不到方法

I'm sure it's possible to do using caller, but yet can't find how

推荐答案

在与 caller 讨论了一段时间后，它可能不会为你做这件事，caller_locations 也不会.可以跟踪在当前线程上实例化的最后一个对象的类，例如

After futzing about with caller for a while, it's probably not going to do it for you, and neither is caller_locations. It's possible to track the classes of the last objects instantiated on the current thread, e.g.

class Class
  alias :_new :new
  def new *args
    Thread.current.thread_variable_set :classes, ((Thread.current.thread_variable_get(:classes) || []) << self).last(10)
    _new *args
  end
end

这保留了最后 10 个对象的类，但这并不直接等同于层次结构，例如

This retains the classes of the last 10 objects, but this isn't directly equivalent to a hierarchy e.g.

class X
  def initialize
    puts Thread.current.thread_variable_get(:classes)
  end
end

class Y
end

class Z
  def initialize
    @y = Y.new
    @x = X.new
  end
end

X.new 输出以下内容(在控制台会话中)

X.new outputs the following (in a console session)

RubyToken::TkNL
RubyToken::TkEND
RubyToken::TkNL
RubyToken::TkCONSTANT
RubyToken::TkDOT
RubyToken::TkIDENTIFIER
RubyToken::TkNL
Y
Z
X

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