iOS release not working as expected - ios

Question

I am using this code to get book names from a config.plist file. However my memory management is problematic. The '[dict release]' breaks the app completely and it exits.
The code works when the '[dict release]' is removed but it causes memory leaks as far as I can tell.
bnames is a global NSMutableArray
What am I doing wrong?
- (NSString *)loadBookname: (NSInteger) bookToLoad {
bookToLoad = [self bookOrder:bookToLoad];
//---get the path to the property list file---
plistFileNameConf = [[self documentsPath] stringByAppendingPathComponent:#"Config.plist"];
//---if the property list file can be found---
if ([[NSFileManager defaultManager] fileExistsAtPath:plistFileNameConf]) {
//---load the content of the property list file into a NSDictionary object---
dict = [[NSDictionary alloc] initWithContentsOfFile:plistFileNameConf];
bnames = [dict valueForKey:#"BookNames"];
[dict release];
}
else {
//---load the property list from the Resources folder---
NSString *pListPath = [[NSBundle mainBundle] pathForResource:#"Config" ofType:#"plist"];
dict = [[NSDictionary alloc] initWithContentsOfFile:pListPath];
bnames = [dict valueForKey:#"BookNames"];
[dict release];
}
plistFileNameConf = nil;
NSString *bookNameTemp;
bookNameTemp = [bnames objectAtIndex:bookToLoad - 1];
NSLog(#"bookName: %#", bookNameTemp);
return bookNameTemp;
}

Answer 1

You need to allocate your array properly:
bnames = [[NSArray alloc] initWithArray:[dict valueForKey:#"BookNames"]];
Double check that your dict returns the right data type.

Answer 2

There does not appear to be anything wrong with the way you allocate NSDictionary (although you could also use the [NSDictionary dictionaryWithContentsOfFile:] and save yourself having to worry about the release.
Either way I would suggest the issue is not with the [release] but probably the line BEFORE release:
bnames = [dict valueForKey:#"BookNames"];
a) Where is that allocated. I don't see an allocation or declaration of it anywhere?
b) What type of value do you expect back?
Put a break point on it and make sure your getting what you expect or anything.

Answer 3

If dict is not already a strong property, make it one. Then, use self.dict when assigning to it (and keep the release).

Answer 4

I've found what appears to be a better solution to the issue. This lets iOS manage the memory.
//---finds the path to the application's Documents directory---
- (NSString *) documentsPath {
NSLog(#"Start documentsPath");
NSArray *paths = NSSearchPathForDirectoriesInDomains(NSDocumentDirectory, NSUserDomainMask, YES);
NSString *documentsDir = [paths objectAtIndex:0];
// NSLog(#"Found documentsPath 40");
NSLog(#"End documentsPath");
return documentsDir;
}
- (NSString *) configPath {
NSLog(#"Start configPath");
NSString *plistFileNameConf = [[self documentsPath] stringByAppendingPathComponent:#"Config.plist"];
if (![[NSFileManager defaultManager] fileExistsAtPath:plistFileNameConf]) {
plistFileNameConf = [[NSBundle mainBundle] pathForResource:#"Config" ofType:#"plist"];
}
NSLog(#"plistFile: %#",plistFileNameConf);
NSLog(#"End configPath");
return plistFileNameConf;
}
The following calls the above code as necessary:
NSString *Choice;
NSArray *properties;
NSString *errorDesc = nil;
NSPropertyListFormat format;
NSData *plistXML = [[NSFileManager defaultManager] contentsAtPath:[self configPath]];
NSDictionary *temp = (NSDictionary *)[NSPropertyListSerialization propertyListFromData:plistXML mutabilityOption:NSPropertyListMutableContainersAndLeaves format:&format errorDescription:&errorDesc];
if (!temp) {
NSLog(#"Error reading plist: %#, format: %d", errorDesc, format);
}
Choice = [temp objectForKey:#"Choice"];
properties = [temp objectForKey:Choice];