如何在请求范围之外访问Sinatra的Logger

Question

似乎Sinatra的记录器仅在请求处理程序中可用(请参阅https://github.com/sinatra/sinatra#logging),但如果我想在其他地方使用记录器,例如在帮助程序方法或配置中,该怎么办？钩？Sinatra记录仪是否可通过其他方式获得？

Answer 1

文档提供了有关范围的一些示例,但您可以logger在helper块中定义的方法中看到帮助程序,因为帮助程序块具有应用程序范围.在配置中,它不可用,但我倾向于设置我自己的日志,无论如何,在rackup文件中作为常量或类实例变量,然后它在configure(和其他任何地方)中可用.仅作为单个应用程序的示例:

require 'sinatra'
require 'logger'

configure do
  set :logging, nil
  logger = Logger.new STDOUT
  logger.level = Logger::INFO
  logger.datetime_format = '%a %d-%m-%Y %H%M '
  set :logger, logger
end

helpers do
  def check
    settings.logger.info "I'm inside a helper"
    # if you were using Sinatra's logger, you could just call
    # logger.info "I'm inside a helper"
    # and it would work, but only if you've not done the stuff above
    # in the configure block
  end
end

get "/" do
  check # this would work for the way above, or with the Sinatra logger
  "Hello, World!"
end

get "/another" do
  settings.logger.info "Using the settings helper this time" # this only works
  # when you've defined your own logger
  "Hello again"
end

作为更好的"全局"类实例变量的示例:

class MyLogger
  def self.logger
    if @_logger.nil?
      @_logger = Logger.new STDOUT
      @_logger.level = Logger::INFO
      @_logger.datetime_format = '%a %d-%m-%Y %H%M '
    end
    @_logger
  end
end

然后在需要的地方使用:

configure do
  set :logging, nil
  logger = MyLogger.logger
  set :logger, logger
end

或在课堂上:

class AnotherClass

  def some_method
    MyLogger.logger.warn "I'm in some method"
  end

Sinatra也带来了(从1.3开始)带有日志记录的帮助程序,这里有一个记录到STDOUT的方法和一个你可能会觉得有用的文件.