相关疑难解决方法(0)

有一个包含模块和类名的字符串,例如:

"Admin::MetaDatasController"

我如何获得实际课程？

如果没有模块,以下代码可以工作:

Kernel.const_get("MetaDatasController")

但它打破了模块:

ruby-1.8.7-p174 > Kernel.const_get("Admin::MetaDatasController")
NameError: wrong constant name Admin::MetaDatasController
        from (irb):34:in `const_get'
        from (irb):34
ruby-1.8.7-p174 > 

从拍摄前一后进行一些修改,以回应sepp2k的关于命名空间的评论,我已经实现字符串#to_class方法.我在这里分享代码,我相信它可能会被重构,特别是"i"计数器.您的意见表示赞赏.

 class String
   def to_class
     chain = self.split "::"
     i=0
     res = chain.inject(Module) do |ans,obj|
       break if ans.nil?
       i+=1
       klass = ans.const_get(obj)
       # Make sure the current obj is a valid class 
       # Or it's a module but not the last element, 
       # as the last element should be a class
       klass.is_a?(Class) || (klass.is_a?(Module) and i != chain.length) ? klass : nil
     end
   rescue NameError
     nil
   end
 end

 #Tests that should be passed.
 assert_equal(Fixnum,"Fixnum".to_class)
 assert_equal(M::C,"M::C".to_class)
 assert_nil …