Question

So in my view controller, I run code to populate an NSArray of Customer (custom class) objects. This custom class has objects that are of ANOTHER custom class called Address (a customer has a billing address and a shipping address). In the view controller when a customer in the list is selected, it passes a new view controller a customer object, like so:

- (void)tableView:(UITableView *)tableView didSelectRowAtIndexPath:(NSIndexPath *)indexPath {
    InfoViewController *customerinfoViewController = [[InfoViewController alloc] initWithStyle:UITableViewStyleGrouped andCustomer:[[[customers objectAtIndex:indexPath.section] objectAtIndex:indexPath.row] retain]];
    [self.navigationController pushViewController:customerinfoViewController animated:YES];
    [customerinfoViewController release];
}

The first time I visit this view controller while running the application, it works fine. However, when I revisit the view controller, something interesting happens. The application crashes, with unrecognized selector sent to instance 0x00whatever. Using the mouseover debugging feature in xCode, I am finding that the first object of the customer’s shipAddress variable has its type changed from NSString to NSIndexPath. This does not happen to the customer’s billAddress object. Anyone have any idea what is going on here? It seems like I may be having memory management issues but I would definitely like a confirmation on this before I tear my code apart tracking down all the retains and releases….

EDIT: More information here. with the following code, I have an NSMutableArray at the class level. At each iteration of the loop, I am looping through nodes in XML (which works fine). Every time a new letter is detected as the first letter of the name, I create a new subarray and add the customer to it, thus filling my class-level NSMutableArray (customers) with subArrays of customers for each letter of the alphabet detected. My question is about the retains and releases of the cycling customer object. Clang Static says there is an over-retaining error on the customer, but when I fix it according to Clang, the loop crashes. what gives? Related code below:

DDXMLDocument *rootDoc = [[[DDXMLDocument alloc] initWithData:xmlData options:0 error:nil] autorelease];
NSArray *elems = [rootDoc nodesForXPath:@"QBXML/QBXMLMsgsRs/CustomerQueryRs/CustomerRet" error:nil];
DDXMLNode *node;
sectionTitles = [[[NSMutableArray alloc] initWithCapacity:1] retain]; // Letters for UITableView section titles
NSMutableArray *subArray;
NSString *lastchar = @"A";
NSString *testchar; 
int indexCount = -1;
customers = [[[NSMutableArray alloc] initWithCapacity:[elems count]] retain];
Customer *newCust;
for (int i = 0; i < [elems count]; i++) {
    node = [elems objectAtIndex:i];
    newCust  = [[Customer alloc] initWithCustomerRetNode:node];
    testchar = [[newCust fullName] substringToIndex:1];
    if (i == 0 || ![[testchar uppercaseString] isEqualToString:lastchar]) {
        [sectionTitles addObject:testchar];
        lastchar = testchar;
        indexCount++;
        subArray = [[NSMutableArray alloc] initWithCapacity:1];
        [customers addObject:subArray];
        [subArray release];
        [[customers lastObject] addObject:[newCust retain]];
    }
    else {
        [[customers lastObject] addObject:[newCust retain]];
    }
    [newCust release];
}

NOTE: this code works for the most part, but clang doesn’t like it.

EDIT: Addresses in the Customer class are assigned like so (which now does not work after Clang fixes)

...
else if ([tempname isEqualToString:@"BillAddress"])
  billAddress = [billAddress initWithAddressNode:tempnode];
else if ([tempname isEqualToString:@"ShipAddress"])
  shipAddress = [shipAddress initWithAddressNode:tempnode];
...

Answer 1

It sounds like you are having a over release issue, so yes memory management, you might be overreleasing that array you are storing your objects in.Cant really tell from the snippet of code though. Youll have to go and look through the code and find the source. Also using Clang Static Analyzer might be of help to you.