Cant bind data to a table view

Question

Hi,

I have retrieved data from Json URL and displayed it in a table view. I have also inlcuced a button in table view. On clicking the button the data must be transferred to a another table view. The problem is that i could send the data to a view and could display it on a label. But i couldnt bind the dat to table view ... Here's some of the code snippets...

Buy Button...

-(IBAction)Buybutton{
    Product *selectedProduct = [[data products]objectAtIndex:0];    
    CartViewController *cartviewcontroller = [[[CartViewController alloc] initWithNibName:@"CartViewController" bundle:nil]autorelease];    
    cartviewcontroller.product= selectedProduct;
    [self.view addSubview:cartviewcontroller.view]; 
}

CartView...

// Implement viewDidLoad to do additional setup after loading the view, typically from a nib.
- (void)viewDidLoad 
{
    [super viewDidLoad];    
    data = [GlobalData SharedData]; 
    NSMutableArray *prod =[[NSMutableArray alloc]init];     
    prod = [data products]; 
    for(NSDictionary *product in prod){
        Cart *myprod = [[Cart alloc]init];
        myprod.Description = [product Description];

        myprod.ProductImage =[product ProductImage];
        myprod.ProductName = [product ProductName];
        myprod.SalePrice = [product SalePrice];

        [data.carts addObject:myprod];
        [myprod release];
    }
    Cart *cart = [[data carts]objectAtIndex:0];
    NSString *productname=[cart ProductName];
    self.label.text =productname;

    NSLog(@"carts");
}

- (NSInteger)numberOfSectionsInTableView:(UITableView *)tableView {
   return 1;
}

- (NSInteger)tableView:(UITableView *)tableView numberOfRowsInSection:(NSInteger)section {
    return [data.carts count];
}
-(CGFloat)tableView:(UITableView *)tableView heightForRowAtIndexPath:(NSIndexPath *)indexPath  {
    return 75;
}

- (UITableViewCell *)tableView:(UITableView *)tableView cellForRowAtIndexPath:(NSIndexPath *)indexPath {
    NSLog(@"cellforrow");
    static NSString *CellIdentifier = @"Cell";

    ProductCell *cell = [tableView dequeueReusableCellWithIdentifier:CellIdentifier];
    if(cell ==nil)
    {
        cell = [[[ProductCell alloc]initWithFrame:CGRectZero reuseIdentifier:CellIdentifier]autorelease];
    }
    NSUInteger row = [indexPath row];
    Cart *cart = [[data carts]objectAtIndex:row];
    cell.productNameLabel.text = [cart ProductName];

    return cell;    
}

I am also getting the following error in the console

2010-06-11 18:34:29.169 navigation[4109:207] *** -[CartViewController tableView:numberOfRowsInSection:]: message sent to deallocated instance 0xcb4d4f90

Answer 1

Your view controller is autoreleased that's why you have the error in the console.

CartViewController *cartviewcontroller =
    [[[CartViewController alloc] 
            initWithNibName:@"CartViewController" 
            bundle:nil] ***autorelease***];

You should store your view controller in a member variable.

Answer 2

This is depreciated:

cell = [[[ProductCell alloc]initWithFrame:CGRectZero reuseIdentifier:CellIdentifier]autorelease];

Use initWithStyle:reuseIdentifier: instead.

Autorelease isn't a convenience function. It has a specific use. You're only supposed to use it when you are immediately handing an object off to an another external object. Don't use autorelease unless the sending object longer cares if the receiving object lives or dies.

A good rule of thumb is if you ever refer to the receiving object again in the sending object, don't autorelease the receiving object.