Ruby Access Class Variables Easily - ruby

Question

I've created a class that I'm using to store configuration data. Currently the class looks like this:
class Configed
##username = "test#gmail.com"
##password = "password"
##startpage = "http://www.example.com/login"
##nextpage = "http://www.example.com/product"
##loginfield = "username"
##passwordfield = "password"
##parser = "button"
##testpage = "http://www.example.com/product/1"
##button1 = "button1"
def self.username
##username
end
def self.password
##password
end
def self.startpage
##startpage
end
def self.nextpage
##nextpage
end
def self.loginfield
##loginfield
end
def self.passwordfield
##passwordfield
end
def self.parser
##parser
end
def self.testpage
##testpage
end
def self.button1
##button1
end
end
To access the variables I'm using:
# Config file
require_relative 'Configed'
# Parse config
startpage = Configed.startpage
loginfield = Configed.loginfield
passwordfield = Configed.passwordfield
username = Configed.username
password = Configed.password
nextpage = Configed.nextpage
parser = Configed.parser
testpage = Configed.testpage
This is not very modular. Adding additional configuration data needs to be referenced in three places.
Is there a better way of accomplishing this?

Answer 1

You can make class level instance variables...
class Configed
#username = "test#gmail.com"
#password = "password"
#startpage = "http://www.example.com/login"
# ...
class << self
attr_reader :username, :password, :startpage # ...
end
end
It's somewhat more compact, and still gives you
username = Configed.username
# ...
NOTE: there's a lot of good ideas in #philomory 's answer that deserves consideration. The use of YAML in particular would allow you to set up different constants for different environemnts test, development, production etc, and you can load the current environment's configuration options into an OpenStruct created in an initializer. Makes for a more flexible solution.

Answer 2

There are a lot of potential improvements. First of all, no reason to use class variables if you don't want their weird specific inheritance-related behavior, and no reason to use a class at all if you're not going to instantiate it.
You could use a module:
module Configed
module_function
def username
'username'
end
# etc
end
Configed.username
But frankly, you're almost certainly better off using a hash:
Config = {
username: 'username'
# etc
}.freeze
Config[:username]
or, if you prefer method-style access, an OpenStruct:
require 'openstruct' # from standard library
Config = OpenStruct.new(
username: 'username'
# etc
).freeze
Config.username
If they need to be modifiable, just don't freeze them. Also, typically a constant which is not a class or a module (such as a hash) would have a name in ALL_CAPS, e.g. CONFIGED, but, that's a stylistic decision with no actual impact on the code.
Your question refers to 'parsing' the config, but of course, you're not; the config data in your setup (and in my examples so far) is just Ruby code. If you'd rather load it from a non-code file, there's always YAML:
config.yaml:
username: username
password: password
config.rb:
require 'yaml' # from Standard Library
Configed = YAML.load_file('config.yaml')
Configed['username']
or JSON:
config.json:
{
"username": "username",
"password": "password"
}
config.rb:
require 'json' # from Standard Library
Configed = JSON.parse(File.read('config.json'))
Configed['username']