Question

So I did that thing with Xcode where you say analyze and it finds leaks and stuff and here, it says that I am leaking (marked in code below).

// Copy dictionary to memory
NSString *filepath = [[NSBundle mainBundle] pathForResource:@"DataCategoriesDictionary" ofType:@"plist"];
NSDictionary *dataCategoriesDictionary = [[NSDictionary alloc] initWithContentsOfFile:filepath];
self.choices = [[NSMutableDictionary alloc] initWithDictionary:[dataCategoriesDictionary objectForKey:self.chosenCategory]]; // LINE 55
[dataCategoriesDictionary release]; // HERE, the compiler says "Potential leak of an object allocated on line 55"

Even though it doesn’t make any sense that I could be leaking a instance variable, I tried adding a release statement for it anyway and Xcode still gave me the same error. What else could I be leaking?

Answer 1

If choices is a property with retain you are leaking the NSMutableDictionary.

[[NSMutableDictionary alloc] initWithDictionary

Either autorelease or use a temporary.

self.choices = [[[NSMutableDictionary alloc] initWithDictionary:[dataCategoriesDictionary objectForKey:self.chosenCategory]] autorelease];

or (my favorite)

self.choices = [NSMutableDictionary dictionaryWithDictionary:[dataCategoriesDictionary objectForKey:self.chosenCategory];

or

NSMutableDictionary *tempDict = [[NSMutableDictionary alloc] initWithDictionary:[dataCategoriesDictionary objectForKey:self.chosenCategory]];
self.choices = tempDict;
[tempDict release];