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When you use NSKeyedArchiver encodeRootObject to archive a whole graph of objects, does it figure out the graph itself by following pointers, or do you need to specify the links yourself in your encodeWithCoder method?

e.g. If I have

@interface WikiWikiWeb : NSObject { NSMutableArray * firstObject; NSDictionary * secondObject; }

in my WikiWikiWeb.h, do I need

(void)encodeWithCoder:(NSCoder *)coder { [coder encodeObject:firstObject forKey:@”One”]; [coder encodeObject:secondobject forKey:”@”Two”]; }

in WikiWikiWeb.m so that it knows how to form the graph, or will it figure it out from the class definitions?



You need to implement the NSCoding protocol, so yes. – FinlayDobbie

Hi, firstly, this is a brilliant site. I have been software mashing for nearly 20 years and lately I have discovered ObjC and Cocoa, it has to be the best thing to develop with without actually getting to use Smalltalk. Sigh!

Anyway, to the point…today I tried to pickle an NSInvocation through NSArchiver and try as I might, I couldn’t make it happen. I wanted to sent a pickled invocation back to my main thread via NSConnection. The connection works fine, as does the program because, thanks to (I found a ‘dodge’ (casting NSInvocation to unsigned and setting it as the msgid), for which I was very happy to find.


Thanks in advance, Sean Charles

From The Fine Manual:

Note: NSInvocation conforms to the NSCoding protocol, but only supports coding by an NSPortCoder. NSInvocation does not support archiving.

I put together a tutorial on NSKeyedArchiver/NSKeyedUnarchiver and NSCoding: – ScottStevenson