Ruby-on-rails – Best way to create custom config options for the Rails app

configurationenvironmentrubyruby-on-rails

I need to create one config option for my Rails application. It can be the same for all environments. I found that if I set it in environment.rb, it's available in my views, which is exactly what I want…

environment.rb

AUDIOCAST_URI_FORMAT = http://blablalba/blabbitybla/yadda

Works great.

However, I'm a little uneasy. Is this a good way to do it? Is there a way that's more hip?

Best Answer

For general application configuration that doesn't need to be stored in a database table, I like to create a config.yml file within the config directory. For your example, it might look like this:

defaults: &defaults
  audiocast_uri_format: http://blablalba/blabbitybla/yadda

development:
  <<: *defaults

test:
  <<: *defaults

production:
  <<: *defaults

This configuration file gets loaded from a custom initializer in config/initializers:

# Rails 2
APP_CONFIG = YAML.load_file("#{RAILS_ROOT}/config/config.yml")[RAILS_ENV]

# Rails 3+
APP_CONFIG = YAML.load_file(Rails.root.join('config/config.yml'))[Rails.env]

If you're using Rails 3, ensure you don't accidentally add a leading slash to your relative config path.

You can then retrieve the value using:

uri_format = APP_CONFIG['audiocast_uri_format']

See this Railscast for full details.

Related Solutions

R – How to modify Rails’ config within an engine plugin

I would go with the config/initializers route. That is the standard folder to put plugin-specific config code and it will get loaded at the correct time.

For implementation, I would try my hardest to choose sensible defaults for everything that allowed me to not have a config file. (I understand this is not always possible.)

Next I would create a generator with the plugin that would automatically create the config file in config/initializers using:

./script/generate plugin MyPlugin --with-generator

Finally, I would put something in install.rb of my plugin to run the generator script when the plugin is installed. This way the config file is generated automatically with the install, and the user still has an easy way to regenerate if he wants to restore the default configuration.

Ruby-on-rails – How to define custom configuration variables in rails

In Rails 3, Application specific custom configuration data can be placed in the application configuration object. The configuration can be assigned in the initialization files or the environment files -- say for a given application MyApp:

MyApp::Application.config.custom_config_variable = :my_config_setting

Rails.configuration.custom_config_variable = :my_config_setting

To read the setting, simply call the configuration variable without setting it:

Rails.configuration.custom_config_variable
=> :my_config_setting

UPDATE Rails 4

In Rails 4 there a new way for this => http://guides.rubyonrails.org/configuring.html#custom-configuration

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Best Answer

Related Solutions

R – How to modify Rails’ config within an engine plugin

Ruby-on-rails – How to define custom configuration variables in rails

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