how to retain values in the following method? - objective-c

Question

#interface SignDocumentController : UIViewController<NSXMLParserDelegate> {
NSMutableString *signFaxString;
NSString * messageId;
NSMutableData *xmlData;
NSURLConnection *connectionInprogress;
NSURLConnection *connectionInprogress2;
NSString * annotationKey;
NSString *firstName;
NSString *lastName;
NSString *date;
NSString *signature;
IBOutlet UIImageView *image;
}
#property(nonatomic,retain)UIImageView * image;
#end
-(void)parser:(NSXMLParser *)parser
didStartElement:(NSString *) elementName
namespaceURI:(NSString *)namespaceURI
qualifiedName:(NSString *)qName
attributes:(NSDictionary *)attributeDict
{
if ([elementName isEqual:#"SignatureInfo"]) {
signFaxString = [[NSMutableString alloc]init];
firstName = [attributeDict objectForKey:#"FirstName"];
lastName = [attributeDict objectForKey:#"LastName"];
date = [attributeDict objectForKey:#"Date"];
signature = [attributeDict objectForKey:#"Signature"];
}
if ([elementName isEqual:#"AddAnnotationResult"]) {
signFaxString = [[NSMutableString alloc]init];
}
}
the values for firstName, lastName, date, signature do not stay and I get an error when I try accessing firstName, lastName ETC in a different method:
[CFString respondsToSelector:]: message sent to deallocated instance 0x4ec63b0
I have tried using :
firstName = [NSString stringWithString attributeDict objectForKey:#"FirstName"];
but that does not work either. I know this is a silly question but I could use some help.
Thanks

Answer 1

you could also declare the firstName and others as property and retain . As below
#property(nonatomic,retain)NSString* firstName;
#property(nonatomic,retain)NSString* lastName;
#property(nonatomic,retain)NSString* date;
#property(nonatomic,retain)NSString* signature;
And in .m class.
#synthesize firstName,date,lastName,signature;
and release them in dealloc function.
Use with self all your property variable in you class.
self.firstName = [NSString stringWithString:attributeDict objectForKey:#"FirstName"];
EDITED:
Also consider #bbum comment ..

Answer 2

To retain it, just send a retain message to the object.
firstName = [[attributeDict objectForKey:#"FirstName"] retain];
release it later.