动态设置Ruby对象的属性

Question

如何在Ruby中动态设置对象属性,例如

def set_property(obj, prop_name, prop_value)
    #need to do something like > obj.prop_name = prop_value 

    #we can use eval but I'll prefer a faster/cleaner alternative:
    eval "obj.#{prop_name} = #{prop_value}"
end

Answer 1

使用发送:

def set_property(obj, prop_name, prop_value)
    obj.send("#{prop_name}=",prop_value)
end

Answer 2

Object#instance_variable_set() 是你正在寻找的,是你想要的更清洁的版本.

例:

your_object = Object.new
your_object.instance_variable_set(:@attribute, 'value')
your_object
# => <Object:0x007fabda110408 @attribute="value">

关于Ruby的文档 Object#instance_variable_set

Answer 3

如果情况允许使用实例方法，以下内容并不过分冒犯：

class P00t
  attr_reader :w00t

  def set_property(name, value)
    prop_name = "@#{name}".to_sym # you need the property name, prefixed with a '@', as a symbol
    self.instance_variable_set(prop_name, value)
  end
end

用法：

p = P00t.new
p.set_property('w00t', 'jeremy')

Answer 4

这个答案（/sf/answers/522646981/）对我有用：

Object.send(attribute + '=', value)

attribute必须是一个String. 因此，如果您要迭代 s 数组Symbol（像我一样），则可以使用to_s.

Object.send(attribute.to_s + '=', value)