README

===  Windy City Rails ===

Metrics based refactoring
=========================

metric_fu - Jake Scruggs
http://github.com/jscruggs/metric_fu

* Flog - code complexity
** http://ruby.sadi.st/Flog.html
* Saikuro - cyclomatic complexity
** http://saikuro.rubyforge.org 
* Reek - bad design detector
** http://github.com/kevinrutherford/reek

Rails 3.1
=========

* Rails 2.3.9 - deprecation notices for upgrading

* Engines
** http://piotrsarnacki.com/2010/09/14/mountable-engines/
** Namespacing
** Engine specific routes
** Migrations 

Various WCR Notes
=================

* In many web applications, dynamic generation takes factors of less time than static pull of content, and so going nuts over optimizing the first part of the pull will only effect that small factor
* Open source community is a marketplace

=====    Railsconf    ======

How to work with legacy code
============================

Tests really help allowing you to make change
  This is not every place in your codebase
  Test around your hotspots
  Look at your commit history
  Do bug fixes cause more bug fixes?

3 Experiments
    Find the most executed paths of your code
        These should be cleanest and tested
    Play Open / Closed Whack-a-mole
        Good code is open to extension but closed to modification
    Run dojo experiments
        take the same piece of code and throw it at 30 developers
        run again - how do they change the code
        how do we react when confronted with code
        how does the way we structure frame how people react

Yehuda After Hours
==================

Hey you - you're overriding behavior incorrectly
------------------------------------------------

class Person
    def say(thing)
        puts thing
    end
end

Person.new.say('hello')

class Person
    alias old_say say
    def say(thing)
        old_say thing.upcase
    end
end

### easier way ###

module Speaker
    def say(thing)
        puts thing
    end
end

class Person
    include Speaker
end

Person.new.say('hello')

module Yeller
    def say(thing)
        super(thing.upcase)
    end
end

class Person
    include Yeller
end

Person.new.say('hello')

ActiveSupport::Concern
----------------------

ActiveSupport::Concern # instead of doing self.included
                       # will pull in ClassMethods automagically

module MyFeature
  extend ActiveSupport::Concern
  included do

  end
end

Deep and dirty in Rails
=======================

Things to know when trying to share state w/ threads
----------------------------------------------------

threading - 3 tips - don't - do not share state - do not share mutable state

operator assignment is not atomic
    +=
    ||=


gem install atomic # an Atomic class that guarantees atomic updates to its contained value

my_atomic = Atomic.new(0)
my_atomic.update {|v| v + 1}
begin
  my_atomic.try_update {|v| v + 1}
rescue Atomic::ConcurrentUpdateError => cue
  # deal with it (retry, propagate, etc)
end

no thread safe string, array, or hash
  do not use mutating operation

define_method
  blocks carry carry around too much state

GC hidden cost of object-heavy languages
  do not create so many objects # fewer objects == better performance

Side Note that I liked
----------------------
Tests are tests - the red part of red, green, refactor
  if it doesn't turn red - your tests aren't testing anything