Rails - how to make global object

Question

I want to parse a XML document once - at Rails application startup. It is parsed to an object, and I want this object to be accessible from anywhere, from any user session. How to implement this application-level object the right way?

possible duplicate of [Ruby on Rails: Where to define global constants?](http://stackoverflow.com/questions/4110866/ruby-on-rails-where-to-define-global-constants) — Holger Just, Mar 27 '12 at 13:53
May be, but there are small constants defined. Is this approach applicable to a large object? — Paul, Mar 27 '12 at 14:08
I think you should do it somewhere within initializers in config folder. — Pavel S, Mar 27 '12 at 14:30
I'm asking not about where to DO it, but where to PUT the result of doing. — Paul, Mar 27 '12 at 14:31
For example, I created a "/config/initializers/init_xml_data.rb" where is one line defined "MY_DATA = MyXmlReference.new", but one of controllers complains about "uninitialized constant TheController::MY_DATA" — Paul, Mar 27 '12 at 14:36

score 1 · Accepted Answer · answered Mar 27 '12 at 15:35

If you just need information from the xml and you can have it as simple hashes/arrays/strings, and no specific object is necessary, you could use Settingslogic for this - normally it takes yaml file and then is accessible throughout the whole application. For example, you define a class:

# app/models/settings.rb
class Settings < Settingslogic
  source "#{Rails.root}/config/application.yml"
  namespace Rails.env
end

# config/application.yml
defaults: &defaults
  global: 'Hello'

development:
  <<: *defaults
  more:
    data: [1, 2, 3]

And then you can use it anywhere like this:

> Settings.global
=> "Hello"
> Settings.more.data
=> [1, 2, 3]

Rails - how to make global object

1 Answers1