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(no subject) [message #687194] Tue, 14 June 2011 07:59 Go to next message
John Smith is currently offline John SmithFriend
Messages: 137
Registered: July 2009
Senior Member
Is it possible, that if a CDO object is already stored in the database,
that the object can be changed later to be instance of a subtype of the
original type?
From the logical aspect, this should cause no big problems since all
references between this object and other objects remain unaffected. From
the aspect of modelling, it supports a top-down modelling approach
somehow, i.e. users want to refine existing elements. So if this feature
not yet exists, it would be nice to have.
(no subject) [message #687195 is a reply to message #687194] Tue, 14 June 2011 08:38 Go to previous message
Eike Stepper is currently offline Eike StepperFriend
Messages: 6444
Registered: July 2009
Senior Member
Am 14.06.2011 09:59, schrieb exquisitus:
> Is it possible, that if a CDO object is already stored in the database, that the object can be changed later to be instance of a subtype of the original type?
What is the original type?

The EClass and the CDOID of a CDOObject can not change over time or over branches.

> From the logical aspect, this should cause no big problems since all references between this object and other objects remain unaffected.
It's weird from the perspective of auditing or branching if an object all of a sudden changes its type. Technically it's impossible because generated EObjects are Java objects and those can't change their class.

> From the aspect of modelling, it supports a top-down modelling approach somehow, i.e. users want to refine existing elements. So if this feature not yet exists, it would be nice to have.
I don't see what *common* problems this feature would solve. This feature is not likely making it to the public code base.

Cheers
/Eike

----
http://www.esc-net.de
http://thegordian.blogspot.com
http://twitter.com/eikestepper


(no subject) [message #687456 is a reply to message #687194] Tue, 14 June 2011 08:38 Go to previous message
Eike Stepper is currently offline Eike StepperFriend
Messages: 6444
Registered: July 2009
Senior Member
Am 14.06.2011 09:59, schrieb exquisitus:
> Is it possible, that if a CDO object is already stored in the database, that the object can be changed later to be instance of a subtype of the original type?
What is the original type?

The EClass and the CDOID of a CDOObject can not change over time or over branches.

> From the logical aspect, this should cause no big problems since all references between this object and other objects remain unaffected.
It's weird from the perspective of auditing or branching if an object all of a sudden changes its type. Technically it's impossible because generated EObjects are Java objects and those can't change their class.

> From the aspect of modelling, it supports a top-down modelling approach somehow, i.e. users want to refine existing elements. So if this feature not yet exists, it would be nice to have.
I don't see what *common* problems this feature would solve. This feature is not likely making it to the public code base.

Cheers
/Eike

----
http://www.esc-net.de
http://thegordian.blogspot.com
http://twitter.com/eikestepper


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