class Author < ActiveRecord::Base has_many :posts has_many :posts_with_comments, :include => :comments, :class_name => "Post" has_many :posts_with_categories, :include => :categories, :class_name => "Post" has_many :posts_with_comments_and_categories, :include => [ :comments, :categories ], :order => "posts.id", :class_name => "Post" has_many :posts_with_callbacks, :class_name => "Post", :before_add => :log_before_adding, :after_add => :log_after_adding, :before_remove => :log_before_removing, :after_remove => :log_after_removing has_many :posts_with_proc_callbacks, :class_name => "Post", :before_add => Proc.new {|o, r| o.post_log << "before_adding#{r.id}"}, :after_add => Proc.new {|o, r| o.post_log << "after_adding#{r.id}"}, :before_remove => Proc.new {|o, r| o.post_log << "before_removing#{r.id}"}, :after_remove => Proc.new {|o, r| o.post_log << "after_removing#{r.id}"} has_many :posts_with_multiple_callbacks, :class_name => "Post", :before_add => [:log_before_adding, Proc.new {|o, r| o.post_log << "before_adding_proc#{r.id}"}], :after_add => [:log_after_adding, Proc.new {|o, r| o.post_log << "after_adding_proc#{r.id}"}] has_many :unchangable_posts, :class_name => "Post", :before_add => :raise_exception, :after_add => :log_after_adding attr_accessor :post_log def after_initialize @post_log = [] end private def log_before_adding(object) @post_log << "before_adding#{object.id}" end def log_after_adding(object) @post_log << "after_adding#{object.id}" end def log_before_removing(object) @post_log << "before_removing#{object.id}" end def log_after_removing(object) @post_log << "after_removing#{object.id}" end def raise_exception(object) raise Exception.new("You can't add a post") end end