Aquarium: Ruby Aspect-Oriented Programming - Polyglot

42 Pages·2008·3.09 MB·English

by  Dean Wampler

Aquarium:
Aspect-Oriented
Programming for Ruby
Dean Wampler, Object Mentor
[email protected]
April 7, 2008
Monday, April 7, 2008 1
What is AOP?
Is it necessary for Ruby?
Aquarium in action
Monday, April 7, 2008 2
class Account
attr_reader :balance
def credit amount
raise "..." unless amount >= 0
@balance += amount
end
def debit amount
raise “…” unless amount < @balance
@balance -= amount
end
end
Monday, April 7, 2008 3
Clean
and
Simple
Monday, April 7, 2008 4
But, Real Applications Need:
class Account
Transactions
attr_reader :balance
def credit amount; …; end
Persistence
def debit amount; …; end
end
Security
Monday, April 7, 2008 5
Tangled
Account
Code
Monday, April 7, 2008 6
Scattered
Persistence,
Transactions,
Security, ...
Code
Monday, April 7, 2008 7
Modularity
is
Compromised.
Monday, April 7, 2008 8
Rails Solution
class Account < ActiveRecord::Base
…
end
Monday, April 7, 2008 9
But what if you want
“PORO’s”??
(Plain Old Ruby Objects)
Monday, April 7, 2008 10