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@StevenJL
Last active August 15, 2019 17:38
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class Account < ActiveRecord::Base
def withdraw(amount)
# ...
end
def deposit(amount)
# ...
end
def close!
update_attribute!(closed_at, Time.current)
end
end
# These three types of accounts inherit from a common base class
# so they can all share a common `#close` method. However, each
# class has its own class-specific methods.
class CorporateAccount < Account
def close!
inform_share_holders!
super
end
end
class SmallBusinessAccount < Account
def close!
inform_mom_and_pop!
super
end
end
class PersonalAccount < Account
def close!
inform_dude_or_dudette!
super
end
end
# Rails is smart enough to detect STI if we add a `type` column
# in the `accounts` table.
class CreateAccounts < ActiveRecord::Migration
def change
create_table :accounts do |t|
t.string :type
t.float :balance
t.string :tax_identifier
t.date_time :closed_at
# ... more column fields #
t.timestamps
end
end
end
# Creation of a corporate account will create a new record in the
# `accounts` table, but with `type` equal to "corporate".
CorporateAccount.create(name: "Evil Corp", tax_identifier: "6664201369" ...)
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