How to add a method to an existing class and use it in rails environment

rubyonrails-talk
1

Hi,

I am using rails 2.0.2 version and I have a need to add a method to an existing class and use it in the rails environment. For example, I would like to add a method to Numeric class, so I coded it as follows

class Numeric    def radians       self * Math::PI/180    end end

and then placed it under <my rails app>/lib directory. However I am not able use this new method in my apps controller, ruby throws no method found error.

Did I do something wrong?

Thanks Babu

2

the code is ok I think. but if it's in lib, you would have to require it before you can use it so if the file is named numeric.rb then require "numeric" either in environment.rb or in the controller or mode where it is used

another option is to put the file in config/initializers this should be loaded by default (though I haven't used this yet)

3

If it goes in environment.rb (which is where I put anything that will be needed anywhere in the application), you'll need to restart your server. Can't speak about the initializers. Haven't used them yet.

Peace, Phillip

4

Thanks for the replies. I tried placing the class definition directly in environment.rb, it works but any updates to the definition requires server restart.

Probably I'll try placing the .rb file under libs directory and require statement in controller or directly in the model.

Thanks again -Babu

5

Phillip Koebbe wrote:

If it goes in environment.rb (which is where I put anything that will be needed anywhere in the application), you'll need to restart your server. Can't speak about the initializers. Haven't used them yet.

Oh, I should clarify that I don't mean to put the actual method definitions in environment.rb. I always put those in a file in lib/. What I meant was if the require <file> were to go in environment.rb, then a server restart is required when you change lib/file.

Sorry for the confusion.

Phillip