Rails Gotchas

From eyeRwiki

A log of all the stupid mistakes I make while learning rails. Maybe someone will find them useful.

[edit] ActiveRecord initialize

DO NOT Override the initialize method of ActiveRecord. It only causes problems!

[edit] Serializing an array of custom classes =

class Board < ActiveRecord::Base
  # The next line is necessary if you want @pegs to unserialize
  #  in the expected manner. If you don't have it, YAML won't know
  #  what class the items in the array should be.
  require 'board_peg'
  serialize :pegs
  
  def setup_board
    self.pegs = [BoardPeg.new, BoardPeg.new, BoardPeg.new]
  end
end

class BoardPeg
  ...
end

[edit] Associations w/o default names

If you decide to override the default name of a has_one/has_many and belongs_to relationship, you CAN NOT just do this:

class Person < ActiveRecord::Base
  has_one :car, :class_name => "Vehicle"

class Vehicle < ActiveRecord::Base
  belongs_to :driver, :class => "Person"

You MUST include foreign keys like so:

class Person < ActiveRecord::Base
  has_one :car, :class_name => "Vehicle", :foreign_key => "person_id"

class Vehicle < ActiveRecord::Base
  belongs_to :driver, :class => "Person", :foreign_key => "person_id"