Order of a standard Model

best_model.rb

class Model < ParentModel
  include Foo::Bar
  extend Bar::Baz
  acts_as_authentic
  dsl_specific_flags 

  module InternalModule
    ...
  end

  default_scope :order => 'id ASC'

  belongs_to :foo
  has_one :baz
  has_many :bars
  has_many :maz, :through => :daz
  has_and_belongs_to_many :jaz
  serialize :bars, Hash
  ...

  before_validation :foo
  after_validation :bar
  before_save :baz
  before_create :taz
  after_create :daz
  after_save :maz
  after_commit :laz
  ...

  validates_presence_of :id
  validates_uniqueness_of :id
  validates_inclusion_of :rating, :in => [1..10]
  validates_numericality_of :taz
  ...

  accepts_nested_attributes_for :foobar

  scope :by_name, :order => 'name ASC'
  scope :lambda_scope, :lambda => { |lambda| { ... } }
  ...

  attr_reader :foobaz
  attr_accessor :foobar

  delegate :barbaz, :to => :foo
  ...

  def self.class_method
  end

  def instance_method
  end

  protected

  def self.class_method
  end

  def instance_method
  end

  private

  def self.class_method
  end

  def instance_method
  end
end

Don't forget callbacks. I tend to put them fairly high in the class definition. If I recall correctly, in the past I've experienced some problems because they were declared below some other things.

Good point. I added them. :)

Now how about "virtual" attributes created via attr_accessor? Where do you put them?

And what about other common class-scope DSLs? One that comes to mind is the Thinking Sphinx define_index block.

Other examples of the above are CarrierWave's mount_uploader and AuthLogics acts_as_authentic.

Oh, what about accepts_nested_attributes_for?

wouldn't you put accepts... beside the association it applied to? i'd say that made more sense

and put all the scopes (default and normal ones) together

+1 @lenary, I want to know if a model accepts nested attributes for one of its associations so I tend to put this on its own lines:

 belongs_to :foo

 has_many :bars
 accepts_nested_attributes_for :bars