Re: [Rubycocoa-talk] Objective-C Ubiquity?

[Jonathan P. <jp...@dc...>]

On 4 Jun 2005, at 20:37, Dave Howell wrote:

> My outlets were named things like "taskDue," "taskTitle," and  
> "taskDescription," and when I added the actions, I named them  
> "setTaskDue," "setTaskTitle," and "setTaskDescription." Xcode or IB  
> or Cocoa or I-don't-know-who's-fault-this-is obviously decided they  
> were related in some way and broke everything for me.

There's a convention that means that rather than directly change the  
instance variable in your class, if there's a method named  
'setSomeName' where 'someName' is the name of the instance variable,  
it'll get used instead.

This is the Key-Value Coding system used in Cocoa Bindings. Read more  
here:

http://developer.apple.com/documentation/Cocoa/Conceptual/ 
CocoaBindings/CocoaBindings.html

Specifically, see the documentation for the setValue:forKey: method:

http://developer.apple.com/documentation/Cocoa/Reference/Foundation/ 
ObjC_classic/Protocols/NSKeyValueCoding.html#//apple_ref/doc/uid/ 
20000471-BABEHECF

> I have gone back and put my outlets back in with names that can't  
> be matched up, and now things work properly. I have no idea where  
> I'd even find this "feature" documented. Sigh. Caveat Programmeri.

I usually name my outlets indicating what they're connected to - for  
example: "taskTitleField".

It's worth taking a look at Cocoa Bindings. They don't solve every  
situation, but for the situations they're designed for they make life  
very easy. A little extra support code is needed in RubyCocoa to make  
them work (see http://rubycocoa.sourceforge.net/w.en/FAQ.html and my  
previous posts to the list on the matter).

I'm afraid, however, that it's probably worth working through the one  
of the Objective C examples first.