ruby - 获取调用者类

Question

我在写 Logger 时遇到了自动添加类名的问题，我从中调用了 print_log 方法。例如这样的事情:

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:

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

我确定可以使用caller，但还找不到方法

Answer 1

你可以像那样使用模块(Rails 风格):

module Loggable
  extend ActiveSupport::Concern

  def log_prefix
    @log_prefix ||= (self.class == Class ? "#{self.to_s}" : "#{self.class.to_s}").freeze
  end

  included do
    [:debug, :info, :warn, :error, :fatal].each do |level|
      define_method level do |str = nil|
        caller = caller_locations(1,1)[0].label
        prefix = "[#{log_prefix}##{caller}] "
        prefix << level.to_s.upcase[0]
        str = "#{prefix}: #{str}"
        puts str if ENV["DEBUG"]
        Rails.logger.send(level, str)
      end
    end
  end
end

你的代码将是:

class MyClass
  include Loggable
  extend Loggable

  def instance_method
    debug "Hello"
  end

  def self.klass_method
    debug "Klass"
  end
end