S for Single responsibility principle
Note
O for Open closed principle which means , a class should be close for modification and open for extension
Example:
Note
class Order < ActiveRecord::Base
def self.find_purchased
# ...
end
def self.find_waiting_for_review
# ...
end
def self.find_waiting_for_sign_off
# ...
end
def self.find_waiting_for_sign_off
# ...
end
def self.advanced_search(fields, options = {})
def self.simple_search(terms)
end
def to_xml
# ...
end
def to_json
# ...
end
def to_csv
# ...
end
def to_pdf
# ...
end
# ...
end
O for Open closed principle which means , a class should be close for modification and open for extension
Example:
class Purchase
def initialize(payment_process)
@payment_process = payment_process
end
def charge_user!
@payment_process.charge(user: user, amount: amount)
end
end
Purchase.new(MachPayAdapter).charge_user!
class Stripe
def charge(user,amount)
end
end
class Paypal
def charge(user,amount)
end
end
class MachPay
def charge_amount(amount,user)
end
end
class MachPayAdapter
def charge(user,amount)
MachPay.charge_amount(amount,user)
end
end
I notice people are still referring to this guide now and then, so I wanted to post a link to a grub2 guide. There are differences so you may want to check there as well