Storing NSMutableArray of UIViews in NSUserDefaults - objective-c

Question

I have read several posts about this but I'm not able to fix the error. If someone could please help.
Here is the code I use. I have an NSMutableArray called list.
-(void) awakeFromNib
{
prefs=[[NSUserDefaults standardUserDefaults]retain];
if ([prefs arrayForKey:#"list"]) {
list=[[NSMutableArray alloc]initWithArray:[prefs objectForKey:#"list"]];
}
else {
list=[[NSMutableArray alloc]init];
}
}
-(void)saveData
{
NSLog(#"saving data!");
[prefs setObject:list forKey:#"list"];
}
- (void)dealloc {
[self saveData];
[prefs synchronize];
[prefs release];
}

Answer 1

You cannot store UIView instances in the user defaults, but only objects that can be serialized in a property list (see here) Also, as #Justin said, do not retain or release the defaults object.

Answer 2

Thank you. However, I had earlier read that you cannot save an NSMutableArray in NSUserDefaults so I attempted to convert it to NSData and then use it.
Here's my ViewController.m file:
-(id)initWithCoder:(NSCoder *)aDecoder
{
self=[[calViewController alloc]init];
if (self!=nil) {
self.list=[aDecoder decodeObjectForKey:#"list"];
}
return self;
}
-(void)encodeWithCoder:(NSCoder *)aCoder
{
[aCoder encodeObject:list forKey:#"list"];
}
And here's my AppDelegate.m file:
-(void) applicationDidFinishLaunching:(UIApplication *)application
{
NSLog(#"Application did finish launching");
defaults=[NSUserDefaults standardUserDefaults];
NSData *dataRepresentingSavedArray=[defaults objectForKey:#"lastArray"];
if (dataRepresentingSavedArray!=nil) {
NSArray *oldSavedArray = [NSKeyedUnarchiver unarchiveObjectWithData:dataRepresentingSavedArray];
if (oldSavedArray != nil)
{
listAr = [[NSMutableArray alloc] initWithArray:oldSavedArray];
else
{
listAr = [[NSMutableArray alloc] init];
NSLog(#"listAr: %#",listAr);
}
}
}
-(void) applicationWillTerminate:(UIApplication *)application
{
[[NSUserDefaults standardUserDefaults] setObject:[NSKeyedArchiver archivedDataWithRootObject:listAr] forKey:#"lastArray"];
}
I've never used UserDefaults before and I absolutely confused. I've read all the docs but I don't seem to be getting it right!
EDIT:
-(void) applicationDidFinishLaunching:(UIApplication *)application
{
NSLog(#"Application did finish launching");
defaults=[NSUserDefaults standardUserDefaults];
if ([defaults objectForKey:#"lastArray"]) {
NSData *dataRepresentingSavedArray=[defaults objectForKey:#"lastArray"];
if (dataRepresentingSavedArray!=nil) {
NSArray *oldSavedArray = [NSKeyedUnarchiver unarchiveObjectWithData:dataRepresentingSavedArray];
if (oldSavedArray != nil)
listAr = [[NSMutableArray alloc] initWithArray:oldSavedArray];
}
}
else
{
listAr = [[NSMutableArray alloc] init];
NSLog(#"listAr: %#",listAr);
}
}