EXC_BAD_ACCESS when using NSKeyedUnarchiver to load saved state - cocos2d-iphone

Question

I have subclassed a CCSprite to make an object that can be encoded and decoded. I want to save sprites state and load it again at particular positions. Everything seems to be okay apart from decoding with NSKeyedUnarchiver (see loadIconSpriteState below) which gives an EXC_BAD_ACCESS Below is the code:
HelloWorldLayer.h
#interface CCIconSprite : CCSprite {
NSString *iconName;
float iconXPos;
float iconYPos;
}
#property (nonatomic, retain) NSString *iconName;
#property (nonatomic, assign) float iconXPos;
#property (nonatomic, assign) float iconYPos;
+ (id)iconWithType:(NSString*)imageName;
- (id)initWithIconType:(NSString*)imageName;
#end
#interface HelloWorldLayer : CCLayer < NSCoding>
{
CCIconSprite* testSprite;
BOOL savedState;
CGSize size;
CCMoveTo* moveTo;
NSMutableArray* saveSpriteArray;
NSData* savedSpriteData;
}
+(CCScene *) scene;
#end
HelloWorldLayer.m:
CCIconSprite implementation:
#implementation CCIconSprite
#synthesize iconXPos;
#synthesize iconYPos;
#synthesize iconName;
+ (id)iconWithType:(NSString*)imageName
{
return [[[[self class] alloc] initWithIconType:imageName] autorelease];
}
- (id)initWithIconType:(NSString*)imageName
{
self = [super initWithFile:imageName];
if (!self) return nil;
iconName = imageName;
self.position = ccp(iconXPos, iconYPos);
return self;
}
Encoding and decoding:
- (id)initWithCoder:(NSCoder *)decoder {
NSString* imageFileName = [decoder decodeObjectForKey:#"imageFileName"];
self = [self initWithIconType:imageFileName];
if (!self) return nil;
self.iconXPos = [decoder decodeFloatForKey:#"iconXPos"];
self.iconYPos = [decoder decodeFloatForKey:#"iconYPos"];
return self;
}
- (void)encodeWithCoder:(NSCoder *)encoder
{
[encoder encodeObject:iconName forKey:#"imageFileName"];
[encoder encodeFloat:self.iconXPos forKey:#"iconXPos"];
[encoder encodeFloat:self.iconYPos forKey:#"iconYPos"];
}
#end
HelloWorldLayer implementation:
#implementation HelloWorldLayer
+(CCScene *) scene
{
CCScene *scene = [CCScene node];
HelloWorldLayer *layer = [HelloWorldLayer node];
[scene addChild: layer];
return scene;
}
-(id) init
{
if( (self=[super init]) ) {
self.scale = 0.5;
savedState = NO;
size = [[CCDirector sharedDirector] winSize];
testSprite = [CCIconSprite spriteWithFile:#"Icon.png"];
testSprite.position = ccp(size.width/4, size.width/4);
testSprite.anchorPoint = ccp(0,0);
[self addChild:testSprite];
moveTo = [CCMoveTo actionWithDuration:3 position:ccp(3*size.width/4, 3*size.width/4)];
[testSprite runAction:moveTo];
[self schedule:#selector(saveAndLoadSpriteState)];
}
return self;
}
Saving and loading state:
-(void)saveIconSpriteState {
saveSpriteArray = [[NSMutableArray alloc] init];
[saveSpriteArray addObject:testSprite];
savedSpriteData = [NSKeyedArchiver archivedDataWithRootObject:saveSpriteArray];
}
-(void)loadIconSpriteState {
[NSKeyedUnarchiver unarchiveObjectWithData:savedSpriteData];
}
-(void)saveAndLoadSpriteState {
if ((testSprite.position.x > size.width/2) && !savedState) {
savedState = YES;
[self saveIconSpriteState];
}
else if ((testSprite.position.x == 3*size.width/4) && savedState) {
savedState = NO;
[self loadIconSpriteState];
[testSprite runAction:moveTo];
}
}
#end
EDIT
After setting an exception break point I got the following error
Assertion failure in -[CCIconSprite initWithFile:]
pointing to the in line:
NSAssert(filename != nil, #"Invalid filename for sprite");
in the
-(id) initWithFile:(NSString*)filename
method of the CCSprite.m class.

Answer 1

Just a hunch but maybe that's it. When decoding a string, you should copy it because you don't own it at this point, nor are you assigning it to a strong or copy property.
- (id)initWithCoder:(NSCoder *)decoder {
NSString* imageFileName = [[decoder decodeObjectForKey:#"imageFileName"] copy];
self = [self initWithIconType:imageFileName];
if (!self) return nil;
...
}
If that's not it, set a breakpoint and verify that the string is indeed correct when encoding and when decoding.