Re: [Zope-dev] zpatterns: how to invalidate the attributecache?

2000-08-26 Thread Phillip J. Eby

At 04:32 PM 8/21/00 +0400, Jephte CLAIN wrote:
"Phillip J. Eby" wrote:
 I don't see a need for a mass invalidation operation, just more
 documentation on these inner workings.  :)

or the lack of an attribute depencies mechanism :-)
if attribute x depends on attribute y from another generic attribute
provider, invalidation of y doesn't make y to be recomputed.


You can do that with a custom attribute provider also.  At this point,
however, I have not run into a situation where I or my developers have
needed that.  In general, we have taken the approach that "dependencies
(such as triggers, indexing, etc.) are only validated/executed at
(sub)transaction boundaries."  In other words, an approach in keeping with
Zope's optimistic transaction approach.

If there is enough demand, I might implement a SkinScript construct to
specify code to be executed immediately after an attribute changes, or to
(semi-)automatically invalidate dependent attributes.  IMHO, however, I
think this sort of situation is one to be avoided if at all possible,
because dependencies have a way of becoming spaghetti (think complex
makefiles).


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Re: [Zope-dev] zpatterns: how to invalidate the attributecache?

2000-08-21 Thread Jephte CLAIN

"Phillip J. Eby" wrote:
 I don't see a need for a mass invalidation operation, just more
 documentation on these inner workings.  :)

or the lack of an attribute depencies mechanism :-)
if attribute x depends on attribute y from another generic attribute
provider, invalidation of y doesn't make y to be recomputed.

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