Re: Debugging a NibLoad binding error

FROM : mmalc crawford
DATE : Tue Jan 08 17:53:03 2008

On Jan 8, 2008, at 8:18 AM, Steve Cronin wrote:

> mmalc;
>
> OK I see that but which object?  Which Nib is loading?  How do I 
> figure this out?
> My basic question is how do I use the debugger to help me find out 
> this kind of information.
>
> Can I enter something useful (a debugger command?) in the breakpoint 
> window
> What would I 'po' in the console window in order to make headway?
> What is the best source of a document along the lines of 'how to use 
> the XCode Debugger: 20 case studies'?
>

Well, the Xcode User Guide would probably be a good place to start:
<http://developer.apple.com/documentation/DeveloperTools/Conceptual/XcodeUserGuide/Contents/Resources/en.lproj/06_02_db_set_up_debug/chapter_42_section_1.html#//apple_ref/doc/uid/TP40002699-BABDECGI
>
Then perhaps the GDB documentation:
<http://developer.apple.com/documentation/DeveloperTools/gdb/gdb/gdb_toc.html
>
particularly, say:
<http://developer.apple.com/documentation/DeveloperTools/gdb/gdb/gdb_6.html#SEC31
>

so that you can break on setNilValueForKey:.


But this all seems to be the secondary consideration.
At first glance, as noted in the previous reply, you have a model 
objet that has a scalar attribute and you haven't implemented 
setNilValueForKey:.  Presumably you know which that is.  So the first 
thing to decide would be, what should be the behaviour on setting 
nil?  Is this a situation you want to allow for?  In which case 
implement setNilValueForKey: and your troubles should be over.  If you 
don't want to allow for it, then proceed to step b.  And if you don't 
want to work through the debugger documentation just yet, you could 
still implement setNilValueForKey: for relevant classes so that they 
print out information about the receiver...

mmalc