Attempt to insert non-property value Objective C

Question

Hi l am trying to create a fourates lists from an restaurants Object, my application has a list of different restaurants, l want the ability for users to add favourate restauran

Answer 1

You can only store property list types (array, data, string, number, date, dictionary) or urls in NSUserDefaults. You'll need to convert your model object to those.

Answer 2

If you don't want to bother about ensuring all your dictionary values are the property list types, then you can simply convert the dictionary into NSData,

NSUserDefaults *def = [NSUserDefaults standardUserDefaults];
[def setObject:[NSKeyedArchiver archivedDataWithRootObject:self.myDictionary] forKey:@"MyData"];
[def synchronize];

And to get back into a dictionary from sandbox:

NSUserDefaults *def = [NSUserDefaults standardUserDefaults];
NSData *data = [def objectForKey:@"MyData"];
NSDictionary *retrievedDictionary = [NSKeyedUnarchiver unarchiveObjectWithData:data];
self.myDictionary = [[NSDictionary alloc] initWithDictionary:retrievedDictionary];

Hope this helps someone. :D

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ADDITIONAL NOTE: If you are getting a mutable dictionary, or mutable array, then remember to use "mutableCopy" method. Otherwise you can't add or delete objects from your retrieved dictionary/array. For example:

NSMutableDictionary *retrievedDictionary = 
[[NSKeyedUnarchiver unarchiveObjectWithData:data] mutableCopy];

Or

NSMutableArray *retrievedArray = 
[[NSKeyedUnarchiver unarchiveObjectWithData:data] mutableCopy];