Assigning nsarray of custom objects to ivar results in memory leak

[maek75]

Hi, I store an NSArray of Calculators using NSUserDefault and NSKeyedArchiver. The content is stored fine and I can iterate the content without any memory leakage or app crach.

When the I navigate from the mainViewController to the subview (handled by the CalculatorListViewController) the method reloadTable is called and the array of calculators is unarchived and set to my listContent ivar in the controller. The contents of the array is displayed correctly in the tableview. However, when returning back to the mainView the app either crates or a memory leak is detected using the performance tools in xcode.

I believe the Calculator object is ok, and - as said - I can from within the subviewcontroller iterate the array of calculators without problem. The leakage always occurs after setting the array to the ivar (self.listcontent = …). I've tried retain and lots of stuff, but nothing seems to work.

All help is very appreciated:-)
Below, you find the classes….

Regards Martin


//Calculator.h ---------------

@interface Calculator : NSObject<NSCoding> {

NSNumber *width;
NSNumber *height;
NSNumber *numberOfPages;
NSNumber *weight;
NSNumber *result;

}

@property(nonatomic, retain) NSNumber *width;
@property(nonatomic, retain) NSNumber *height;
@property(nonatomic, retain) NSNumber *numberOfPages;
@property(nonatomic, retain) NSNumber *weight;
@property(nonatomic, retain) NSNumber *result;

//Calculator.m --------------

@implementation Calculator

@synthesize width, height, numberOfPages, weight, result;

#pragma mark -
#pragma mark NSCoding Methods

/* This code has been added to support encoding and decoding my objecst */
-(void)encodeWithCoderNSCoder *)encoder{
//Encode the properties of the object
[encoder encodeObject:self.width forKey:@"width"];
[encoder encodeObject:self.height forKey:@"height"];
[encoder encodeObject:self.numberOfPages forKey:@"numberOfPages"];
[encoder encodeObject:self.weight forKey:@"weight"];
[encoder encodeObject:self.result forKey:@"result"];
}

-(id)initWithCoderNSCoder *)decoder{
self = [super init];
if( self != nil ){
//decode the properties
self.width = [decoder decodeObjectForKey:@"width"];
self.height = [decoder decodeObjectForKey:@"height"];
self.numberOfPages = [decoder decodeObjectForKey:@"numberOfPages"];
self.weight = [decoder decodeObjectForKey:@"weight"];
self.result = [decoder decodeObjectForKey:@"result"];
}
return self;
}

-(void)dealloc {
[height release];
[width release];
[numberOfPages release];
[weight release];
[result release];
[super dealloc];
}

----------
Now, when clicking a button on my mainViewcontroller, a subview is presenting a tableview. This subview is handled by the CalculatorListViewController.
The subview is loaded using the code below:

CalculatorListViewController *viewController = [[CalculatorListViewController alloc] initWithNibName:@"CalculatorListViewController" bundle:nil];

[viewController reloadTable];
[self.navigationController pushViewController:viewController animated:YES];
[viewController release];


//CalculatorListViewController.h ---------------------
@interface CalculatorListViewController : UITableViewController <UITableViewDelegate, UITableViewDataSource>{

NSArray *listContent;
NSArray *listContent2;
}

- (void) reloadTable;

@property (nonatomic, retain) NSArray *listContent;


//CalculatorListViewController.m ---------------------
@implementation CalculatorListViewController

@synthesize listContent;

- (void) reloadTable{

NSData *calculationData = [[NSUserDefaults standardUserDefaults] objectForKey:@"calculatorArray"];

if (calculationData != nil){
self.listContent = [NSKeyedUnarchiver unarchiveObjectWithData:calculationData];
}
}

[thomashw]

Are you releasing listContent in dealloc?

Also, please wrap your code in [ CODE ] tags.

[maek75]

Originally Posted by thomashw

Are you releasing listContent in dealloc?

Also, please wrap your code in [ CODE ] tags.

Yes. Then I get the leak when returning. If not released, the app craches when returning.

[maek75]

Originally Posted by maek75

Yes. Then I get the leak when returning. If not released, the app craches when returning.

Just a note; I've tried different ways of allocating the listContent array (but its not shown in the example code). For example:

self.listContent2 = [[NSKeyedUnarchiver unarchiveObjectWithData:calculationData] copy];

[LazyCoder]

Originally Posted by maek75

Just a note; I've tried different ways of allocating the listContent array (but its not shown in the example code). For example:

self.listContent2 = [[NSKeyedUnarchiver unarchiveObjectWithData:calculationData] copy];

Are you sure you removed that line?
It is leaking, if you do not release your object somewhere else.

[maek75]

Originally Posted by LazyCoder

Are you sure you removed that line?
It is leaking, if you do not release your object somewhere else.

It should have been:

self.listContent = [[NSKeyedUnarchiver unarchiveObjectWithData:calculationData] copy];

and that listcontent should have been released in dealloc. But I get a leakage there. How to solve? tried different ways without any luck!

[LazyCoder]

Originally Posted by maek75

It should have been:

self.listContent = [[NSKeyedUnarchiver unarchiveObjectWithData:calculationData] copy];

and that listcontent should have been released in dealloc. But I get a leakage there. How to solve? tried different ways without any luck!

If you copy an object, you own it, and you have to release it.
How you keep track of tht object in your instance is on another page, depends on the declaration of your property.

That line of code is leaking.