Objective C alloc/release error

Question

I have the following problem:

in header;

GDataXMLDocument *doc;
NSString *xmlBody;
@property (nonatomic,copy) NSString *xmlBody;
@property (nonatomic         


        

Answer 1

NSData *xmlData = doc.XMLData;
newXML = [[NSString alloc] initWithBytes:[xmlData bytes] length:[xmlData length] 
encoding:NSUTF8StringEncoding];

What is your newXML? is it a ivar and synthesize it and retain it? if yes the compiler will automatically generate getter and setter methods.

NSData *xmlData = doc.XMLData;
self.newXML = [[NSString alloc] initWithBytes:[xmlData bytes] length:[xmlData length] 
encoding:NSUTF8StringEncoding];
self.timestamp = nil;

If its not property then

NSString* newXML = [[NSString alloc] initWithBytes:[xmlData bytes] length:[xmlData length] 
encoding:NSUTF8StringEncoding];   
self.xmlBody=newXML;   
[newXML release]; 

Answer 2

One "problem" with singleton objects is that they appear to leak. If you create an object and never destroy it, Instruments says it's a leak, even if your intention was never to release it.

Answer 3

This looks wrong:

[doc release];

Why are you releasing an object managed by a property?

In your @synthesize statements change them to:

@synthesize doc = doc_;
@synthesize xmlBody = xmlBody_;

Then fix all the resulting errors to go through the property, releasing the properties ONLY in dealloc.

Edit:

You say it crashes releasing theXML. This code is wrong:

NSString *theXML = [[NSString alloc] initWithBytes:[xmlData bytes] length:[xmlData length] encoding:NSUTF8StringEncoding];  
        theXML =[theXML stringByReplacingOccurrencesOfString:@"inferenceresponse" withString:@"inferencerequest"];
[theXML release];

You alloc a string, replace that variable with the "stringByReplacing..." call with a string that is autoreleased, then try to release the resulting string that is autoreleased which will crash. When you don't need to keep a string around after the method you are in, ALWAYS use autorelease. The correct code is:

 NSString *theXML = [[[NSString alloc] initWithBytes:[xmlData bytes] length:[xmlData length] encoding:NSUTF8StringEncoding] autorelease];  
            theXML =[theXML stringByReplacingOccurrencesOfString:@"inferenceresponse" withString:@"inferencerequest"];

And take out [theXML release] - there will be no leak.

I think you should really switch to using ARC as soon as you possibly can... it will save you from a lot of such misunderstandings.

Answer 4

If you want to release an ivar/property(retain), this is not how to to it:

[self.doc release];

instead:

self.doc = nil;