Title: RE: [regrep] PROPOSAL: More flexible ObjectRef
<Farrukh>
> My proposal is to add a new logical id attribute to the set of
> registry versioning attributes, and otherwise improving ObjectRef to
> allow selection of a particular version of an object.
+1 on being able to reference a logical object in a version independent
manner.
This is exactly what the lid attribute is for in the versioning spec
being added to version 2.6.
I think that the use case you raise can (and should) be addressed very
easily by extending the ObjectRef class to have a choice of:
a) a static "hard-wired" reference to a specific version of a specific
object (current capability)
b) a dynamic "late-binding" reference to a logical object which is
determined at run-time (de-refence time).
I could see this being done via a second attribute named "dynamic". When
dynamic is false (default) the registry
assumes that the id attribute references the referenced object. When
dynamic is true, the registry assumes that the id attribute MUST be to a
stored query that dynamically determines the referenced objects.
This is a very powerful concept. Thanks Matt for seeding this idea. I
hope we can discuss this over email prior to next telecon. Thanks.
</Farrukh>
I also see this as a very valid and a needed Use Case and that LateBinding approach is interesting. However, I think that we have a solution that doesn't need LateBinding. It would be something like this:
- subscribe to relevant event(s); in this case it is Update of the objects that are members of the package.
- implement "Web Service" that is going to be triggered by the above event and that is going to adjust relevant object references.
As one looks at the context of the two, LateBinding would incur lookups whenever object references need to be resolved and EventNotification will be invoked when relevant events happen. One would assume that occurrence frequency of the first is higher then of the second.
Regards,
Nikola
