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?

Answer 1

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]