Adding a instance method

Hi all,

I’d like to add a instance method to class String.

I should be fairly simple with

class String; def newmethod; do_something ; end; end

and it works perfectly if I test this independently with irb.
However if I add this to my application.rb I’ll get an error like

(undefined method `newmethod’ for “123456”:String)

What’s wrong with that?
Thanks
Jens

Hi –

On Sun, 18 Jun 2006, Jens wrote:

(undefined method `newmethod’ for “123456”:String)

What’s wrong with that?

If you do this:

class ApplicationController < ActionController::Base
class String

you’re creating a new String class nested inside
ApplicationController. If you want to get into the top-level String
class, you can put the code at the top:

class String
# stuff here
end

class ApplicationController < ActionController::Base

or you can use the path notation to force a top-level constant:

class ::String

Another option is to put the code in a separate file in the lib
subdirectory of your application, and then ‘require’ it at runtime.
That’s probably a cleaner design.

(And don’t forget the many pitfalls of modifying core classes :slight_smile:

David


David A. Black ([email protected])
Ruby Power and Light, LLC (http://www.rubypowerandlight.com)

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David,

Yep, makes total sense! Thanks a lot for the detailed answer
All the best
Jens