[Zope] Zope Versions unusable?

Jochen Haeberle listen@MIDRAS.de
Mon, 20 Dec 1999 14:43:37 +0100


Hi Jim,

At 11:49 Uhr +0000 20.12.1999, Jim Fulton wrote:
>Hm.  You should have gotten a more informative error message
>that said something alomg the line of "this request could not
>be completed because it modified an object that has been modified in
>a version".
>
>  > Is this something known to you?
>
>Yes.
>
>  > Is this a bug?
>
>No (except for the error message).
>
>  > Does anyone know when
>  > this can happen?
>
>Yes. It happens when you try to modify an an object
>that has been modified in (another) version. When you
>modify an object in a version, the object is locked and
>can only be modified in that version.  The effect of a change
>can be wideer than expected. For example, adding an object
>to a folder modifies the folder.  If changing an
>object causes a catalog to be updated, then changing
>an object in a version locks the catalog, as well as
>the object.

Mhm, not really. Only if you refer to the non Version environment as
a a Version, too (what you probably do), well, then it is probably the
catalog messing up...

But then, it is a real pain... how am I supposed to work on features in
a version if I can't try it using the catalog...

>  > Are there things to avoid when working in a version?
>
>Avoid changing objects you don't want to lock.

:-) How to in a system that autoupdates the catalog???

>  > If this happens rather often and unknown to the content manager, I
>  > guess the Versions of Zope are rather unusable, because they do not
>  > protect your working securly!
>
>Perhaps.  This is a function of the objects you are working with,
>Objects that make far flung changes (e.g. objects that modify a
>central catalog) or objects that make changes in non-management
>situtations don't work well with versions.  Perhaps objects
>that behave this way should provide some sort of warning when used
>in a version.

Yes, that's true. Thanks for your detailed answer, but unfortunately 
you left me
with a big questionmark on my face :-(

Jochen