Question

我有一个ruby类，在其中一个方法中，它调用一个外部函数，并传入所有实例变量，并继续返回值。这是代码：

class MyClass
  attr_accessor :name1
  attr_accessor :name2
  ...
  attr_accessor :namen


  def inner_func():
    all_vars = ???? # how to collect all my instance variables into a dict/Hash?
    res = out_func(all_vars)
    do_more_stuff(res)
  end
end

问题是实例变量可能在子类中有所不同。我不能把它们称为他们的名字。那么，有没有办法做到这一点？或者我是否以错误的方式思考？

Answer 1

您可以使用instance_variables在阵列中收集它们。您将获得所有初始化的实例变量。

class MyClass
  attr_accessor :name1
  attr_accessor :name2
  ...
  attr_accessor :namen


  def inner_func():
    all_vars = instance_variables
    res = out_func(all_vars)
    do_more_stuff(res)
  end
end

Answer 2

您可以在创建时跟踪所有访问者：

class Receiver
  def work(arguments)
    puts "Working with #{arguments.inspect}"
  end
end

class MyClass
  def self.attr_accessor(*arguments)
    super
    @__attribute_names__ ||= []
    @__attribute_names__ += arguments
  end

  def self.attribute_names
    @__attribute_names__
  end

  def self.inherited(base)
    parent = self
    base.class_eval do
      @__attribute_names__ = parent.attribute_names
    end
  end

  def attributes
    self.class.attribute_names.each_with_object({}) do |attribute_name, result|
      result[attribute_name] = public_send(attribute_name)
    end
  end

  def work
    Receiver.new.work(attributes)
  end

  attr_accessor :foo
  attr_accessor :bar
end

class MySubclass < MyClass
  attr_accessor :baz
end

用法

my_class = MyClass.new
my_class.foo = 123
my_class.bar = 234
my_class.work
# Working with {:foo=>123, :bar=>234}

my_subclass = MySubclass.new
my_subclass.foo = 123
my_subclass.bar = 234
my_subclass.baz = 345
my_subclass.work
# Working with {:foo=>123, :bar=>234, :baz=>345}

如何在ruby类中获取所有实例变量？

2 个答案: