UIImage * is a __NSCFArray instead of a UIImage - iphone

Question

My app has a user select a photo from the picker. I apply the selected image to a view and then I save it to a file and reference that file in user defaults so when the UserProfile is created that avatar is loaded in.
When I close the app and then start it again, the app loads the image from the file. After loading the image from the file, my app is crashing when I apply it to an Image view because it is seen as an __NSCFArray. There is no method scale on __NSCFArray. Why is it being cast to this class?
-[__NSCFArray scale]: unrecognized selector sent to instance 0x145260
* Terminating app due to uncaught exception
'NSInvalidArgumentException', reason: '[__NSCFArray scale]:
unrecognized selector sent to instance 0x145260'
Here is my code where the UIImage is created from a file:
#implementation UserProfile
- (id) init {
self = [super init];
if(self) {
NSUserDefaults *userDefaults = [NSUserDefaults standardUserDefaults];
_username = (NSString *)[userDefaults objectForKey:USERNAME_KEY];
NSString *filename = (NSString *) [userDefaults objectForKey:#"AvatarFilename"];
NSLog(#"filename from user defaults: %#",filename);
if (filename) {
_avatar = [UIImage imageWithContentsOfFile:filename];
if (!_avatar) NSLog(#"LOGERROR: avatar was not created from file");
_customAvatar = TRUE;
} else {
_customAvatar = FALSE;
_avatar = [UIImage imageNamed:DEFAULT_AVATAR_FILENAME];
if (!_avatar) NSLog(#"LOGERROR: avatar was not created from default");
}
[self createThumbnail];
}
return self;
}
Note: in my createThumbnail code I call this [_avatar isKindOfClass:[UIImage class] and it says it is a UIImage. But then when I set the view, it thinks it is an __NSCFArray. I don't even understand how this is possible since the property is a UIImage *.
This is how the image is persisted
- (void) setAvatar:(UIImage *)image
{
NSUserDefaults *userDefaults = [NSUserDefaults standardUserDefaults];
NSString *filename = nil;
if (image) {
if (_avatar) [_avatar release];
_avatar = [image retain];
_customAvatar = TRUE;
filename = [NSString stringWithFormat:#"%#/%#",[MyUtilities applicationDocumentsDirectory],AVATAR_FILENAME];
if (![UIImagePNGRepresentation(image) writeToFile:filename atomically:YES])
NSLog(#"LOGERROR: Failure to write avatar file");
else NSLog(#"saved avatar to PNG file");
} else {
NSLog(#"setting default avatar");
_avatar = [UIImage imageNamed:DEFAULT_AVATAR_FILENAME];
_customAvatar = FALSE;
}
[userDefaults setObject:filename forKey:AVATAR_KEY];
// TODO If performance is crucial, consider creating a default thumbnail as well
[self createThumbnail];
if(![userDefaults synchronize])
{
NSLog(#"LOGERROR: Failure to synchronize userDefaults");
}
}
To my knowledge I am not receiving a memory warning.

Answer 1

You are assigning autoreleased objects to your ivars. Most likely they are being deallocated and then when you try to access one of those UIImage it happens to be an NSArray at the same memory address.
_username = (NSString *)[userDefaults objectForKey:USERNAME_KEY];
...
_avatar = [UIImage imageWithContentsOfFile:filename];
...
_avatar = [UIImage imageNamed:DEFAULT_AVATAR_FILENAME];
You need to retain them.

Answer 2

You are saving autoreleased object (return by imageNamed: and imageWithContentsOfFile:) without retaining in init. You can replace that method with next one:
- (id) init {
self = [super init];
if(self) {
NSUserDefaults *userDefaults = [NSUserDefaults standardUserDefaults];
_username = (NSString *)[userDefaults objectForKey:USERNAME_KEY];
NSString *filename = (NSString *) [userDefaults objectForKey:#"AvatarFilename"];
NSLog(#"filename from user defaults: %#",filename);
if (filename) {
_avatar = [[UIImage imageWithContentsOfFile:filename] retain];
if (!_avatar) NSLog(#"LOGERROR: avatar was not created from file");
_customAvatar = TRUE;
} else {
_customAvatar = FALSE;
_avatar = [[UIImage imageNamed:DEFAULT_AVATAR_FILENAME] retain];
if (!_avatar) NSLog(#"LOGERROR: avatar was not created from default");
}
[self createThumbnail];
}
return self;
}
You don't need to retain this object anymore.
Just release it in dealloc.
In setAvatar: you should also retain returned by imageNamed: value : _avatar = [[UIImage imageNamed:DEFAULT_AVATAR_FILENAME] retain];