Ruby中的跨领域日志记录
发布时间:2020-12-17 03:57:48 所属栏目:百科 来源:网络整理
导读:我正在尝试从外部向方法添加日志记录(面向方面??的样式) class A def test puts "I'm Doing something..." endendclass A # with logging! alias_method :test_orig,:test def test puts "Log Message!" test_orig endenda = A.newa.test 上面的工作没问题,
我正在尝试从外部向方法添加日志记录(面向方面??的样式)
class A def test puts "I'm Doing something..." end end class A # with logging! alias_method :test_orig,:test def test puts "Log Message!" test_orig end end a = A.new a.test 上面的工作没问题,只是如果我再次需要为方法做别名,它会进入一个无限循环.我想要一些更像super的东西,我可以根据需要多次扩展它,并且每个扩展名都使用别名作为其父级. 解决方法
另一种方法是使用未绑定的方法:
class A original_test = instance_method(:test) define_method(:test) do puts "Log Message!" original_test.bind(self).call end end class A original_test = instance_method(:test) counter = 0 define_method(:test) do counter += 1 puts "Counter = #{counter}" original_test.bind(self).call end end irb> A.new.test Counter = 1 Log Message! #=> #.... irb> A.new.test Counter = 2 Log Message! #=> #..... 这样做的好处是它不会使用其他方法名称污染命名空间,并且如果你想创建一个类方法add_logging或者你有什么,那么相当容易抽象. class Module def add_logging(*method_names) method_names.each do |method_name| original_method = instance_method(method_name) define_method(method_name) do |*args,&blk| puts "logging #{method_name}" original_method.bind(self).call(*args,&blk) end end end end class A add_logging :test end 或者,如果你想能够在很多锅炉板上做很多方面,你可以编写一个方法来编写方面添加方法! class Module def self.define_aspect(aspect_name,&definition) define_method(:"add_#{aspect_name}") do |*method_names| method_names.each do |method_name| original_method = instance_method(method_name) define_method(method_name,&(definition[method_name,original_method])) end end end # make an add_logging method define_aspect :logging do |method_name,original_method| lambda do |*args,&blk| puts "Logging #{method_name}" original_method.bind(self).call(*args,&blk) end end # make an add_counting method global_counter = 0 define_aspect :counting do |method_name,original_method| local_counter = 0 lambda do |*args,&blk| global_counter += 1 local_counter += 1 puts "Counters: global@#{global_counter},local@#{local_counter}" original_method.bind(self).call(*args,&blk) end end end class A def test puts "I'm Doing something..." end def test1 puts "I'm Doing something once..." end def test2 puts "I'm Doing something twice..." puts "I'm Doing something twice..." end def test3 puts "I'm Doing something thrice..." puts "I'm Doing something thrice..." puts "I'm Doing something thrice..." end def other_tests puts "I'm Doing something else..." end add_logging :test,:test2,:test3 add_counting :other_tests,:test1,:test3 end (编辑:李大同) 【声明】本站内容均来自网络,其相关言论仅代表作者个人观点,不代表本站立场。若无意侵犯到您的权利,请及时与联系站长删除相关内容! |