Standing on the shoulders of giants

• first place to look in rails code
  • routes
    • start by looking at the url, use routes to look deeper in the 'hood'
• notes
  • amazing intro lol
  • hilarious pictures
  • not a talk about identify - l
  • learning from other people
  • "if I have seen a little further it is by standing on the shoulders of Giants" - Isaac Newton
  • be responsible for legacy code
• Why stand on the shoulders of giants?
  • "To see further"
    • To really learn from the masters
    • understand the domain
    • "listen & learn"
• Control your destiny
  • constantly refactor your code
    • bad idea
  • actually learn and get better
• We all write legacy code
  • time passes, and shit gets old
• Protect yourself from, five days ago
• You're surrounded by idiots
  • avoid really bad code
  • a little less than 50% of people suck
• Why is reading code hard?
  • languages that aren't Ruby
    • not everything will be ruby
  • ruby is good to learn off of, nice and clear
  • Unfamiliar idioms
• Code Written by non-heroes
• The skills that pay the bills
  • a hemet with a light on it
  • go exploring "spelunking"
    • "where no one has gone before"
    • make a plan and execute it
    • one part of this code you need to figure out right now
    • don't get distracted by alternate caves
  • use your tools
    • find and grep are your friends
    • don't chase rabbit holes
• Examples
  • xmlrpc4r - michael neumann
    • standard library, on all of our machines
  • Beast - Rick Olson, Josh Goebel
    • find(:stuff)
    • find out that user is admin by following routes, user.admin true if users < 0
  • authenticated_system.rb - Rick Olson
    • might be legacy after dhh's keynote
  • Rake - Jim Weirich
    • Overloading the language
  • acts_as_versioned - Rick Olson
• Spelunking Rails Recipe - Adam
  • bullets
    • Grok any methods the ation calls
    • Check the template any helpers it might use
    • Grok the controller action
    • Grok any controller filters
    • Check out the controller or skip directly to the view
    • Look at the URL, cross reference with routes.rb
• Rails spelunking, the preface
  • filters defined in ApplicationController or helpers in ApplicationHelper
  • Observers,validations,callbacks,etc. defined in models
  • code in lib or plugins
• Anatomy of a plugin
  • init.rb is called by rails
  • framework-punching involves including or extending classes in AR,AP,etc ("monkeypatching")
• Metaprogramming skillz
  • class_eval to manipualte classes at runtime
• RJS - Marcel Molina Jr. and Sam Stephenson