adding a method to built-in class in rails app

Question

I want to add a method to the Array class in a rails app. Where should I put this method?

EDIT to be clearer, obviously I put it in a file somewhere, but how do I tell the rails app about where to find it?

Answer 1

Just put it in a new file, e.g. array_extended.rb

class Array

  def my_new_method()
    ...
  end

end

After that you may include this file with require "array_extended.rb". Be sure you don't override already existing methods as this may break other functionality.

Answer 2

One way to do this is to create a file at lib/rails_extensions.rb. Then, add your extensions like so:

class Array
  def bring_me_food
    # ...
  end

  def make_tea
    # ...
  end
end

class Hash
  def rub_my_shoulders
    # ...
  end
end

Then in config/environment.rb, add this:

require 'rails_extensions'

Your mileage with subservient objects may vary.

Answer 3

By default, when you call "require", Rails will look in (from the Rails edge source):

app app/metal app/models app/controllers app/helpers app/services lib vendor

For simplicity's sake, put the file in lib/, and require it by name in your config/environment.rb, or you can put it in config/initializers/array_extension.rb, and it'll be automatically loaded.

Where I work, we've put all of our extensions to the core Ruby library into a plugin, and stored it in (Rails.root/)vendor/plugins/utilities/lib/core_ext, and then we require the individual extensions in the plugin's init.rb.

Another way to skin this cat: if you say, want to store your core extensions in Rails.root/core_ext, then you can add that path as a load path in your configuration block in environment.rb:

Rails::Initializer.run do |config|
  config.load_paths << 'core_ext'
end

Then you can call "require 'array_extension'" from anywhere, and it'll load.