[Zope3-dev] persistence by adaptation, and aop?

Ken Manheimer klm@zope.com
Tue, 3 Jun 2003 11:59:38 -0400 (EDT)


In jon udell's latest column, he notices a pattern in several flavors
of java object persistence mechanisms - an aspect-oriented programming
characterization.  It got me to thinking about how we continue to do
persistence as a mixin for objects, and wondering whether we could do
it with our alternative to AOP, adapters...  I don't know enough about
components' innards to judge, and am wondering what those i in the
know think of the idea?

The article is at:

  http://www.infoworld.com/article/03/05/30/22OPstrategic_1.html 

The article is short, but it's still worth repeating a single
paragraph which sums up the observation:

  For object or relational databases, simple objects, and EJBs, the
  same underlying technique has been used to achieve persistence. When
  I see a repeating pattern, I listen to what it's telling me. In this
  case, the message has little to do with the practice of hacking Java
  bytecodes and everything to do with an emerging discipline called
  AOP (aspect-oriented programming). Seen through the AOP lens,
  persistence is something you declare about an object, not something
  intrinsic to it. The "managed" middleware environments (J2EE, COM+)
  take a similarly declarative approach, as do the new breed of Web
  services management solutions. AOP is crossing from theory to
  practice, but it's a profoundly unifying idea that will resonate
  throughout the industry.

(I may be off base comparing the component approach with aspect
oriented programming.  I strongly suspect, though, that they address
the same purpose.  That purpose is something like packaging
functionality so it can be conveyed to any situation where it is
useful without being locked in with other, independent functionality.
And form the little i've seen of AOP approaches, components seem to me
to encapsulate the extensibility in way that's much more congruent
with the rest of OOP...)

-- 
Ken
klm@zope.com