IMO, this comes at this at the wrong direction. Objects should not decide whether they can be added to a given folder, the folder should be the one that makes that decision. It gives me the heebie geebies to think that every time the add list is rendered, a whole slew of class methods are potentially called to determine what gets put there. This also invokes my ui chaos alarm. It gives things such arbitrary ability to dynamically affect the ui, that it may cause mass confusion by users who can't understand why an object is addable in one folder but not in another (seemingly identical) folder. Granted, this is somewhat possible right now (using permissions), but this pushes it a bit over the edge for me. It smells too much like magic. -Casey Toby Dickenson wrote:
Re: http://dev.zope.org/Wikis/DevSite/Proposals/RestrictedCreation
This proposal from Itamar has been up on dev.zope.org for a while, proposing a way for a registered type to control whether or not it can be added to a container, or a per-container basis.
I now have an implementation of this in CVS in the toby-metatypes-branch. I propose this goes into zope 2.6. Any comments?
(Ive CCed everyone who has commented on the proposal; I hope thats OK)