[Zope-dev] Re: data migration from zope 2.6.1 to zope 2.7.0-b2

[AltKey]

Paul Winkler wrote:
> On Fri, Feb 06, 2004 at 03:12:39PM -0600, J Cameron Cooper wrote:
> 
>>altkey wrote:
>>
>>
>>>I am fairly new to zope & python but I am working to migrate some 
>>>data/objects from zope 2.6.1 to zope 2.7.0-b2 (and eventually 2.7.0 
>>>final.
>>>
>>>What I am doing is this.
>>>   (1) get Dublin core metadata + some Dublin core extensions for the 
>>>objects
>>>   (2) get pure text representation of object content - I can't use  
>>>a simple import/export in zexp format because the classes in the 
>>>receiving zope instance differ significantly from the classes in the 
>>>sending zope instance.
>>>
>>>I am able to collect all the data mentioned above and pass it across 
>>>to the new 2.7.0-b2 zope instance but i am having trouble getting my 
>>>objects to live where they need to live; specifically their path is 
>>>not being accepted properly when i recreate the objects.
>>
>>Before trying to deal with the problem you state, I'll make two possibly 
>>simplifying observations:
>>
>>1. There should be no need to do any migration when upgrading Zope. The 
>>ZODB has not changed, and you may simply copy it over or upgrade Zope in 
>>place.
>>
>>2. ZSyncer is the best magic for copying objects from one instance to 
>>another.
> 
> 
> I doubt it will help. ZSyncer is a shortcut for export -> import,
> and altkey wants to convert between two different classes.
> Also zsyncer currently enforces (stupidly) that the two
> zopes must have the same folder hierarchy - you can't
> sync /foo/bar/baz to /bat/bar/baz.
> 
> altkey, maybe you should break this into multiple steps, some
> of which are apparently done already;
> something like:
> 
> 1) write code that extracts data from an old class.
> 
> 2) write code that creates an instance of the new class
> from this data.
> 
> note that this is on one server so the classes must have
> different names or live in different modules.
> i think you're ok here already.
> 
> 3) write a script that upgrades a single object "in place" by
> doing #1, deleting the object, then doing #2
> 
> 4) write a script that walks a folder tree and does #3
> on all instances of the old class.
> 
> 5) use zsyncer or export / import to copy the objects
> from the old zope to the new zope.
> 
> 
What I am doing is transferring data (not full objects) from one 
Zope/CMF instance to another. The change of Zope version isn't the issue 
for me. The issue is the classes present in the two instances. the first 
instance zope 2.6.1 has a number of products that were written by the 
group i work with (DF 2.0) and the receiving instance zope 2.7.0-b2 has 
different classes (DF 3.0) which naturally could not accept the objects 
from zodb because the supporting classes are not present in their 
intended new home.

What I am having trouble is the path that 
myObject.invokeFactory(type,id) uses. I try to set up a specific path 
for myObject but the invokeFactory puts the new object into the DF root 
rather than into the path for myObject.

I do  not understand zope well enough to sort out the problem for myself 
yet, so i posted a question here and in the CMF news group.

If you or anybody else can help I'd appreciate it very much.

Cheers
AlyKey (aka Phil)