Re: Object Hierarchies
Re: Object Hierarchies
- Subject: Re: Object Hierarchies
- From: Matt Neuburg <email@hidden>
- Date: Sun, 29 Apr 2007 16:58:15 -0700
- Thread-topic: Object Hierarchies
On Sat, 28 Apr 2007 22:09:46 -0500, Sam Colombo <email@hidden> said:
> This question relates to bindings and a hierarchy of lists, each level
>of which may have different properties. We have done all this once before,
>the hard way in C++, and are trying to see what we could do in Cocoa. We
>have been looking at MailDemo, available on the web, and wondered if the
>following would make sense. We have a hierarchy of objects, each having a
>list of lower-level objects, i.e.:
>
>Course -> Session -> Segment -> Scene -> Shot -> Layer -> Shape ->
>ContentProperties
>
> Does it make sense, a la MailDemo, to subclass these from a common class
>having only two instance variables, i.e., an (NSMutableArray*)sublist and an
>(NSMutableDictionary*)properties, the latter of which would be individually
>initialized with all the keyed properties associated with the particular
>subclass? Or maybe even just use one class with individual initializers?
>This would be in lieu of defining individual instance variables and
>accessors. Is there a downside to this approach?
>
> We also have a set of tabbed views, each containing a table that
>displays properties corresponding to one of the above levels. In addition,
>we would like to have an alternative tree view of the full structure. Each
>individual level would have its own NSArrayController subclass and I assume
>there would be one NSTreeController subclass.
I'm not quite sure what "the hard way" is, or why you think Cocoa would be
any different. However, off the top of my head, this sounds like perhaps a
job for Core Data, which is all about abstracting the commonly needed
behaviors of object graphs. m.
--
matt neuburg, phd = email@hidden, <http://www.tidbits.com/matt/>
A fool + a tool + an autorelease pool = cool!
AppleScript: the Definitive Guide - Second Edition!
<http://www.amazon.com/gp/product/0596102119>
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