[Modeling-users] Another question about sessions and EditingContexts (sorry)

[Ernesto Revilla]

Dear all,

as stated in the documentation, section 6. Integration in an application, using an application server, actually it is recomended to use a fresh EditingContext for each session. But it states also, that changes made permanent with saveChanges will not be visible to other EditingContexts. Is the also the case for Zope ZEditingContextSessioning? Could anybody tell me in which environment she/he uses modeling, and how he treats the EditingContexts? (I'm looking for application server like uses.)

Best regards, Erny

[Sebastien Bigaret]

Post by Ernesto Revilla
Dear all,
as stated in the documentation, section 6. Integration in an application,
using an application server, actually it is recomended to use a fresh
EditingContext for each session. But it states also, that changes made
permanent with saveChanges will not be visible to other EditingContexts. Is
the also the case for Zope ZEditingContextSessioning? Could anybody tell me
in which environment she/he uses modeling, and how he treats the
EditingContexts? (I'm looking for application server like uses.)

This is the case in every multi-ECs environment, including Zope and
ZECSessioning.

I currently have the intention of solving that longstanding issue of
synchronizing ECs --and this is a prerequisite for optimistic
locking. Would you have some time testing patches on that topic?

-- Sébastien.

[Ernesto Revilla]

Dear Sébastien,

Yes, actually I have time to do some testing in a test environment (no production) with sqlite and Postgresql. (And I'm sorry I couldn't help you with python metaclasses in the past.) I'm also very interested in optimistic locking.

With best regards,
Erny



----- Original Message -----
From: "Sebastien Bigaret" <***@users.sourceforge.net>
To: "Ernesto Revilla" <***@sicem.biz>
Cc: "modeling-users" <modeling-***@lists.sourceforge.net>
Sent: Sunday, February 29, 2004 2:37 PM
Subject: Re: [Modeling-users] Another question about sessions and EditingContexts (sorry)

Post by Ernesto Revilla
Dear all,
as stated in the documentation, section 6. Integration in an application,
using an application server, actually it is recomended to use a fresh
EditingContext for each session. But it states also, that changes made
permanent with saveChanges will not be visible to other EditingContexts. Is
the also the case for Zope ZEditingContextSessioning? Could anybody tell me
in which environment she/he uses modeling, and how he treats the
EditingContexts? (I'm looking for application server like uses.)

This is the case in every multi-ECs environment, including Zope and
ZECSessioning.

I currently have the intention of solving that longstanding issue of
synchronizing ECs --and this is a prerequisite for optimistic
locking. Would you have some time testing patches on that topic?

-- Sébastien.

[Sebastien Bigaret]

Hi,

Post by Ernesto Revilla
Dear Sébastien,
Yes, actually I have time to do some testing in a test environment (no production) with sqlite and Postgresql. (And I'm sorry I couldn't help you with python metaclasses in the past.) I'm also very interested in optimistic locking.

Ok, thanks, such a feature needs to be double-checked, and more :)

I began working on it yesterday evening, and hopefully we'll have a
first draft in the coming days. The first conclusion to which I've come
is that optimistic locking is much easier to implement than the
synchronizing of ECs! The second one is that the first implementation
will be a proof of concept, and won't work for child ECs. I'll let you
know when the first patch is available.

-- Sébastien.

[Sebastien Bigaret]

Hi all,

I've just uploaded a patch (#911567) for ECs synchronization upon
saveChanges(), and for optimistic locking.

https://sf.net/tracker/index.php?func=detail&aid=911567&group_id=58935&atid=489337


This is alpha software:

* For now, ECs synchronization works for updated objects, not deleted
ones, and it does not work for nested ECs.

* Optimistic locking is implemented and works well, but it's not been
heavily tested.

The patch is shipped with a new test, test_EC_optimistic_locking.py,
which hopefully demonstrates what can be expected from these new
features.

Bug/error reports will be preferably directed to the corresponding
sf's ticket #911567, and discussions, questions, etc. about the new
feature can take place here on the mailing-list. Thanks in advance to
those who will have some time to test the patch!

-- Sébastien.