我有这样的代码:
module ModuleToPrepend
def perform(*args)
puts args
super
end
end
class Base
prepend ModuleToPrepend
end
class Child < Base
def perform(*args)
do_something(args)
end
end
我正在寻找在每次调用之前打印方法参数的解决方案。我想在类
Child.new.perform
中的祖先列表的开头加上一个模块ModuleToPrepend
我不想在一个类中预先设置它,因为有数百个。我的代码返回此:
Base
我想要这个:
Child
可以用红宝石做吗?
最佳答案
不确定这是否有任何副作用(如果有,请告诉我),但以下方法应该有效:
module ModuleToPrepend
def perform(*args)
puts 'ModuleToPrepend#perform'
puts args
super
end
end
class Base
def self.inherited(subclass)
puts 'Base.inherited'
subclass.prepend(ModuleToPrepend) if subclass.superclass == Base
super
end
end
class Child < Base
def perform(*args)
puts 'Child#perform'
end
end
# => Base.inherited
class Subchild < Child
def perform(*args)
puts 'Subchild#perform'
super
end
end
# => Base.inherited
puts Child.ancestors
# => [ModuleToPrepend, Child, Base, Object, Kernel, BasicObject]
child = Child.new
child.perform('arg1', 'arg2')
# => ModuleToPrepend#perform
# => [arg1, arg2]
# => Child#perform
puts Subchild.ancestors
# => [Subchild, ModuleToPrepend, Child, Base, Object, Kernel, BasicObject]
subchild = Subchild.new
subchild.perform('arg1', 'arg2')
# => Subchild#perform
# => ModuleToPrepend#perform
# => [arg1, arg2]
# => Child#perform