Re: Question about memory management

[Ivan Vučica]

On 7. 6. 2013., at 10:47, David Chisnall <address@hidden> wrote:

> On 7 Jun 2013, at 09:42, Maxthon Chan <address@hidden> wrote:
> 
>> Well can I (just like NSApplication):
>> 
>> 1) In supercalss, define the shared instance as id
>> 2) In superclass, return the shared instance as id or instancetype
>> 3) In superclass, DO NOT set up yet.
>> 4) In superclass, set up in the method asking for the shared instance, which 
>> always use [[self alloc] init]?
> 
> NSApplication is an example of a singleton designed for subclassing.  It 
> provides an explicit mechanism for defining the subclass that should be used 
> for the singleton instance: a string in the Info.plist providing the name of 
> the application class to use.  It also sets up its delegate in this way and 
> gets the name of the nib to load on application start.
> 
> David
> 
> -- Sent from my brain
> 

Also notable is NSDocumentController, which is explicitly being overridden by 
[MyDocumentController sharedController] before first use by either the app or 
the framework; that is, in -applicationWillFinishLaunching:.

I do this to prevent the user from opening more than one document while still 
leveraging other parts of the document architecture.

Regards,

Ivan Vučica
via phone