Where to store configuration URL variable in Rails?

Question

I have an external ecommerce link that varies based based on environment (testing and production systems).

Where should it go in Rails?

Possibilities include:

• a conditional directly in the template, on the button (not a good solution, IMO)
• database (though there's no model for this so it would be a specific case possibly over-generalized)
• application.rb (which I believe is not recommended for this purpose)
• environment-specific application configs
• initializer
• view helper
• YAML file
• (external) environment variable
• etc.

Where would this typically go in Rails?

Some of these keep the template clean, but put a very specific case far away from the place it's used.

Answer 1

Configuration data like this should always be stored in a configuration file. I have the below line in all my rails applications:

# config/application.rb
config.app_config = Rails.application.config_for(:app_config)

You can read more about it here: http://api.rubyonrails.org/classes/Rails/Application.html#method-i-config_for

Answer 2

I store configuration variables like these in YAML files and then load them into the app's configuration in config/application.rb. I believe this is a standard practice.

Example

I configure a URL for something in a config file. For example, this config file is config/client.yml:

defaults: &defaults
 url: 'localhost:8080'
development:
 <<: *defaults
test:
 <<: *defaults
production:
 <<: *defaults

Then I make it available in my app by adding this line to config/application.rb:

config.client = config_for(:client)

That line roughly translates to, "Load the configuration specified in config/client.yml and make it available in the app as Rails.configuration.client".

Now, I can get the URL anywhere in my app via Rails.configuration.client['url'].

So three steps:

1. Create .yml file in config/
2. Declare the file as a config in config/application.rb
3. Access the config in the app via Rails.configuration