how to save NSDictionary in NSUserDefaults

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Level 1

15 points

how to save NSDictionary in NSUserDefaults

hello

i am able to save simple user preferences
like strings, values or bools

but now that i am trying to save more complex user data stored in NSDisctionary
i get error saying i am trying to store non property values:

[[NSUserDefaults standardUserDefaults] setObject:myDictionary forKey:@"savedData"];

i confirmed in the docs that it is possible to save NSArray and NADictionary
i though my issue was because i am trying to save a dictionary of custom classes

but i tried with a simple dictionary with just NSStrings there and it ithrew the same error

i also tried to use the NSArchiver technique described to save NSColor but i also got the same error

pls help !
my users are not able to retrieve saved prefs...

MBP c2d 2.16 / iMac g5 2.1, Mac OS X (10.5.4)

Posted on Sep 7, 2008 9:47 AM

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Answer 1

Sep 7, 2008 10:22 AM in response to Nonnus

Hello Nonnus,

Your custom classes in the NSDictionary wouldn't work because the documents of NSUserDefaults says so. However, just a NSDictionary with only NSStrings should work. In fact, I tried the following and it worked without a problem.

NSUserDefaults* defaults = [NSUserDefaults standardUserDefaults];
NSDictionary* my_dict = [NSDictionary dictionaryWithObject: @"value" forKey: @"key"];
[defaults setObject: my_dict forKey: @"myDict"];
NSLog (@"myDict has been set");

Jake

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Answer 2

Nonnus Author

Level 1

15 points

Sep 7, 2008 10:43 AM in response to Nonnus

tx qlot for your help and attention 🙂

i knew it was stated as possible on the docs
but first attempt threw same errors

i just did some further testing on blank project
(nothing like ablank canvas for testing;)
and i am actually able to save a nsdictionary with strings so i can find a workaround for now 🙂

i still cannot archive other classes like uicolor to get into nsdefaults as well

i am trying to follow their docs but the NSArchiver keeps giving errors:

UIColor* myColor = [UIColor blueColor];
NSData *myData = [NSArchiver archivedDataWithRootObject:myColor];

error: * Terminating app due to uncaught exception 'NSInvalidArgumentException', reason: ' * -encodeInt:forKey: only defined for abstract class. Define -[NSArchiver encodeInt:forKey:]!'

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