> On May 17, 2013, at 1:18 AM, Trygve Inda wrote: > >>> On May 17, 2013, at 12:43 AM, Trygve Inda wrote: >>> >>>> 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. >>> >>> That seems "nice" enough to me. The trick is that the custom class has to >>> be >>> sure to only modify the properties via KVC on itself, not the dictionary, in >>> order to maintain KVO compliance. Another way to put it is that only >>> -setValue:forUndefinedKey: should ever mutate the dictionary (and it should >>> only be invoked by the KVC machinery itself). >> >> Will that work right if I have an NSTableView and one of the columns has a >> binding to "myCustomProperty" (which is not defined in the object model)... >> Will it get sent: >> >> [someObject setValue:someValue forUndefinedKey:myCustomProperty] >> >> Rather than: >> >> [someObject setMyCustomProperty:someValue]; > > Bindings use KVC. They will do: > > [someObject setValue:someValue forKey:@"myCustomProperty"]; > > The KVC machinery is what will eventually call [someObject setValue:someValue > forUndefinedKey:@"myCustomProperty"] for the dynamic properties. (For the > predefined properties, it will invoke your setter methods.) > > >> On disk the data will be stored in a plist and an array of NSDictionaryies >> (some of the key will be required and predefind) but some will be user >> defined. >> >> When I load the data from disk if I use dictionary obejects, I don't have to >> do anything else but if I use custom objects I would have to create them and >> send >> >> [someObject setValue:someValue forUndefinedKey:myCustomProperty] >> >> To each object. >> >> Right? > > You can use -setValuesForKeysWithDictionary: to set all of the properties of > your object from a dictionary. That uses KVC on each key-value pair, so it > works like I described above for bindings. > > That said, you should consider doing proper keyed archiving of your class. > Don't forget the limits of property lists. > > Regards, > Ken > >
So do my user-added properties (that I will store in a dictionary owned by my custom-class object) have to begin with a lowercase letter to have the KVC perform correctly? E.g myCustomField vs MyCustomField? Of course with the direct dictionary method it would not matter. Thanks _______________________________________________ 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
