Question

I have set up an NSXMLParser to parse through a Twitter feed, but I am getting memory leaks, and after sitting through using instruments about a hundred times I can’t figure out where it is! Below is my NSXMLParser code that parses when ASIHTTPRequest receives data back.

-(void)ProcessAndParse{

    NSURL *url = [config urlForFeed:@"Twitter"];
    ASIHTTPRequest *request = [ASIHTTPRequest requestWithURL:url];
    [request setDelegate:self];
    [request startAsynchronous];

}

- (void)requestFinished:(ASIHTTPRequest *)request
{
    NSData *responseData = [request responseData];
   myparser = [[NSXMLParser alloc] initWithData:responseData];
    [myparser setDelegate:self];
    [myparser setShouldResolveExternalEntities:YES];
    [myparser parse];



}

-(void)parser:(NSXMLParser *)parser didStartElement:(NSString *)elementName namespaceURI:(NSString *)namespaceURI qualifiedName:(NSString *)qName attributes:(NSDictionary *)attributeDict
{
    currentElement = [elementName copy];
}

-(void)parser:(NSXMLParser *)parser didEndElement:(NSString *)elementName namespaceURI:(NSString *)namespaceURI qualifiedName:(NSString *)qName{


}

-(void)parserDidEndDocument:(NSXMLParser *)parser{


}

-(void)parser:(NSXMLParser *)parser foundCharacters:(NSString *)string{




}

I know there is quite a bit missing here but I am trying to stop this leak before I go on any further. It seems to center around the currentElement = [elementName copy];in the didStartElement method.

Answer 1

You need to release the previous element, before assigning a new one for currentElement, otherwise the old element won’t have any other references and it will be leaked. So you can do this:

[currentElement release];
currentElement = [elementName copy];

Alternatively you can declare your ivar currentElement property as copy, and simply do this:

//This releases previous value, and copies the new Value.

self.currentElement = elementName;