Accessible

A simple and flexible means of configuration for Ruby applications.

Set up a configuration class

Create a class in your project, include the Accessible module, and load a data source. You may then also merge in any number of additional data sources.

class MyConfig
  include Accessible

  load 'config/defaults.yml'
  merge 'config/environments/dev.yml'
end

Note: The load method will clear out any previously loaded data and replace it with the new data, whereas merge will merge in new data with previously loaded data (i.e. matching keys will be overridden and new keys will be added).

Both load and merge can take any of the following as a data source:

• A filepath to a yaml file (i.e. 'config/default.yml')
• A symbol representing the name of a yaml file found in config/ (i.e. :default)
• A raw hash of data (i.e. { :base_url => 'http://www.example.com' })

Both methods also accept an optional second parameter: the name of a specific key within the data source, whose data is the only data that should be loaded from the source. This is provided in case you prefer to maintain a single configuration file with default and environment specific data separated out under different keys.

Access your configuration data

There are two ways to access your configuration data.

Let's imagine the following data is loaded:

{
  :environments => {
    :dev => {
      :users => [
        { :name => 'user0' },
        { :name => 'user1' },
        { :name => 'user2' }
      ]
    }
  }
}

Methods

You can get and set data by calling methods on your data set that match the name of the keys. If you try to get or set a key does not exist, an error will be thrown.

MyConfig.environments.dev.users[1].name # => 'user1'

MyConfig.environments.dev.users[1].name = 'new_user1'
MyConfig.environments.dev.users[1].name # => 'new_user1'

MyConfig.does_not_exist # => NoMethodError
MyConfig.does_not_exist = 'foo' # => NoMethodError

Brackets

You may also use the familiar :[] and :[]= methods, which behave the same as they do on any hash. :[] will return nil if the key does not exist, :[]= will create and set the key-value pair if the key does not exist. This makes :[] useful for providing default values.

MyConfig[:environments][:dev][:users][1][:name] # => 'user1'

MyConfig[:environments][:dev][:users][1][:name] = 'new_user1'
MyConfig[:environments][:dev][:users][1][:name] # => 'new_user1'

MyConfig[:does_not_exist] || 'default' # => 'default'
MyConfig[:new_key] = 'foo' # => `:new_key => 'foo'` pair is created

---

Check out the unit tests for the nitty-gritty of how things should work.