active record callback

i always worry if myown active_record callback conflicts with rails'
implemented corresponding one.i assume rails itself perhaps also use
active_record callback.for example:

#myown callback
class Book < ActiveRecord::Base
  def after_save
    ...

  end
end

when i define the after_save for Book,i think perhaps this after_save
has overrided rails itself's implemented one,if so,i want to use both of
them.

is my consideration right?
does rails use active_record callbacks? if it is true,how do i take care
of myown's and rails'.

I think what you want may be either
class Book < ActiveRecord::Base
after_save do # note, no def
  .....
end

or
class Book < ActiveRecord::Base
after_save :my_after_save

private
def my_after_save
  .....
end

Colin

thanks,colin.it seems the other two callback ways: handler class and
observer are based on class declaration way,so that no override happens.

Please remember to quote the previous message and insert your comments
inline so someone finding the conversation in the future will be able
to follow the thread more easily. Thanks.

It is not clear from your comment whether your problem is now solved.

Colin

when i define the after_save for Book,i think perhaps this after_save
has overrided rails itself's implemented one,if so,i want to use both of
them.

is my consideration right?
does rails use active_record callbacks? if it is true,how do i take care
of myown's and rails'.

You don't have to guess - you can check what rails does. As far as I
can tell rails doesn't use actual after_save etc. method and always
uses the callback macros (after_save :foo etc.)

Fred