Issue 10739: Describe exact behaviour of compositions and associations in the DLRL. (data-distribution-rtf)
Source: PrismTech (Mr. Erik Hendriks, erik.hendriks(at)prismtech.com)
Nature: Revision
Severity: 
Summary: Problem:

It is possible to annotate certain relations in the XML as being compositions and/or associations. Section 3.1.3.2.2 briefly describes how such relationships should behave. However, although it is possible to enforece constraints on certain relationships on the writer side, it is not possible to enforece them on the reader side. Especially not since the constraints are part of the 'local' object model, while the topics sould have been written by somebody with another 'local' model where these constraints are not enforced.
What should happen to a composition relation where multiple objects claim possession of the same compound object? Or to an association where the associated object does not refer back to the object that associates it?

Solution:

In our opinion these constraints can only be enforced in the local object model, not on the entire system. (Unless of course the entire system shares the same object model). Because of this we propose to enforece these constraints only on the writer side of the DLRL: when objects in a writeable CacheAccess are modified and do not adhere to these constraints, the write operations will raise an InvalidObjects (See also issue PT-DLRL-ARCH-0008).

TBD.

Resolution: 
Revised Text: 
Actions taken:
February 14, 2007: received issue
Discussion: 

End of Annotations:=====
s is issue # 10739	From: "Erik Hendriks" <Erik.Hendriks@prismtech.com>


Describe exact behaviour of compositions and associations in the DLRL.

Problem:

It is possible to annotate certain relations in the XML as being compositions and/or associations. Section 3.1.3.2.2 briefly describes how such relationships should behave. However, although it is possible to enforece constraints on certain relationships on the writer side, it is not possible to enforece them on the reader side. Especially not since the constraints are part of the 'local' object model, while the topics sould have been written by somebody with another 'local' model where these constraints are not enforced.
What should happen to a composition relation where multiple objects claim possession of the same compound object? Or to an association where the associated object does not refer back to the object that associates it?

Solution:

In our opinion these constraints can only be enforced in the local object model, not on the entire system. (Unless of course the entire system shares the same object model). Because of this we propose to enforece these constraints only on the writer side of the DLRL: when objects in a writeable CacheAccess are modified and do not adhere to these constraints, the write operations will raise an InvalidObjects (See also issue PT-DLRL-ARCH-0008).

TBD.