If you go the dictionary route a simple category on NSDictionary would allow you to compute dynamic properties such as area = length * width.
Sandor Szatmari On May 17, 2013, at 1:43, Trygve Inda <cocoa...@xericdesign.com> wrote: > I need to keep a small (few thousand) record database of sorts. Each record > has some pre-detertermined fields, but the user can add there own fields to > to a limited extent. It is a pretty light use so CoreData isn't what I > really want, plus migrating to future structures is an issue with CoreData. > > This will be simple objects in an NSMutableArray. > > I can use an array of NSMutableDictionaries or perhaps an array of > class-based custom cocoa objects. > > One nice thing about the object route is that I can have some fields > (properties) be based on a calculation rather than real storage like they'd > be in an NSMutableDictionary. > > E.g. > > NSNumber length > NSNumber width > NSNumber area > > In an object area could be a method returning length*width instead of an > instance var for area. > > The trouble comes in the fact that I need to be able to add properties at > runtime. For the dictionary option, it is easy - just make sure the key > names don't collide and I can add more keys to each dictionary. > > But for the objects I don't see a nice way to do this > > There is setValue:forUndefinedKey: and then each object could keep a local > dictionary of these "defined at runtime" keys. > > Thoughts on this? > > > > _______________________________________________ > > Cocoa-dev mailing list (Cocoa-dev@lists.apple.com) > > Please do not post admin requests or moderator comments to the list. > Contact the moderators at cocoa-dev-admins(at)lists.apple.com > > Help/Unsubscribe/Update your Subscription: > https://lists.apple.com/mailman/options/cocoa-dev/admin.szatmari.net%40gmail.com > > This email sent to admin.szatmari....@gmail.com _______________________________________________ Cocoa-dev mailing list (Cocoa-dev@lists.apple.com) Please do not post admin requests or moderator comments to the list. Contact the moderators at cocoa-dev-admins(at)lists.apple.com Help/Unsubscribe/Update your Subscription: https://lists.apple.com/mailman/options/cocoa-dev/archive%40mail-archive.com This email sent to arch...@mail-archive.com
