Question

I was trying to use a plist to store an array with the below code:

NSString *name = firstName.text;
    NSString *path = [[NSBundle mainBundle] pathForResource:@"Names" ofType:@"plist"];

    NSMutableArray *namesArray = [[NSMutableArray alloc] initWithContentsOfFile:path];

    [namesArray addObject:name];

    NSArray *paths = NSSearchPathForDirectoriesInDomains(NSDocumentDirectory, NSUserDomainMask, YES);
    NSString *documentsDirectory = [paths objectAtIndex:0];
    [paths release];
    NSString *docDirPath = [documentsDirectory stringByAppendingPathComponent:@"Names.plist"];
    [namesArray writeToFile:docDirPath atomically:YES];

    namesArray = [[NSMutableArray alloc] initWithContentsOfFile:docDirPath];

This code seems to work. Using NSLog, I have found that after this code executes the plist contains what I want it to, however, my program crashes because it generates an EXC_BAD_ACCESS on a device, and on the simulator it just crashes without an explanation. Does anyone know why that might happen?

Answer 1

 NSArray *paths = NSSearchPathForDirectoriesInDomains
(NSDocumentDirectory, NSUserDomainMask, YES); //Auto-released array

NSString *documentsDirectory = [paths objectAtIndex:0];

[paths release]; //Oh noes!

You don’t own the reference to paths, so don’t release it. Remove [paths release] and I’ll bet you’re fine. You’re crashing because the autorelease pool is releasing paths after you’ve already done it yourself.

Quoth the guide:

You only release or autorelease objects you own. You take ownership of an object if you create it using a method whose name begins with “alloc” or “new” or contains “copy” … or if you send it a retain message.