On Tue, Dec 21, 2010 at 8:33 PM, Torsten Bronger <bron...@physik.rwth-aachen.de> wrote: > Hallöchen! > > Marc Aymerich writes: > >> [...] >> >> Morgan, take a look at the inheritanceManager of this app: >> https://github.com/carljm/django-model-utils#readme > > Is anything like this planned for core Django? It's the third or > forth time I see someone needing it.
It's not planned for 1.3. Whether it is planned for 1.4 will depend entirely on whether someone drives the issue. For the record, the use case you describe was considered at the time model inheritance was introduced. If you search the archives for "CORBA narrowing" you should be able to find the thread where Malcolm and I discussed it. At the time, we decided to omit support for 'narrowing' (to use the CORBA parlance) as part of the default feature set because it requires either: a) table overhead to store the type of the child instance b) an expensive query (or list of queries) that isn't obviously expensive. We weren't (and I'm still not) willing to impose either of these overheads by default. The good news is that either strategy is easy to implement without modifications to core. I've got several classes in production that do narrowing-like behavior (for the record, both using strategy (a)). With a bit of extra effort, this should be easy to turn into a mixin that could be shared as part of a third-party support library, much as django-treebeard or django-mptt provide model support extensions implementing tree-like structures. Yours, Russ Magee %-) -- You received this message because you are subscribed to the Google Groups "Django users" group. To post to this group, send email to django-us...@googlegroups.com. To unsubscribe from this group, send email to django-users+unsubscr...@googlegroups.com. For more options, visit this group at http://groups.google.com/group/django-users?hl=en.
