How to retrieve 'attr_accessor' attribute names?

Question

I am using Ruby on Rails 3.0.9 and I would like to retrieve all attr_accessor attribute names starting with a specific string. That is,

... in my module I have:

attr_accessor :prefix_attribute_name1,
              :prefix_attribute_name2,
              :prefix_attribute_name3,
              ...
              :attribute_name1,
              :attribute_name2,
              ...

and I would like to retrieve all attr_accessor attribute names that starts with the :prefix string. How can I do that?

Answer 1

Generally, attr_accessor just creates accessor methods and doesn't have any particular hooks for reflection like that. If you need such a thing you could either write an extension that wraps around attr_accessor with alias_method_chain or you can just make do with this:

(MyClass.instance_methods - Object.instance_methods).grep(/^prefix/).sort

Answer 2

You can grab it using YourClass.instance_methods.select{|i| i.to_s =~ /prefix_/}.