iOS App terminates in connectionDidFinishLoading - ios

Question

iOS app terminates in Xcode simulator in connectionDidFinishLoading on the following line of code.
NSMutableDictionary *dict = [parser objectWithString:[[NSString alloc] initWithData:dataForConnection encoding:NSUTF8StringEncoding] error:nil];
Following the more code of this function
- (void)connectionDidFinishLoading:(NSURLConnection*)connection {
NSMutableData *dataForConnection = [self dataForConnection:(URLConnection*)connection];
NSInteger statusCode=[((URLConnection*)connection).response statusCode];
NSString *tag=((URLConnection*)connection).tagKey;
[self removeReceivedDataHandle:tag];
if (statusCode != 200 && statusCode!=204 && statusCode!=405){
[reportActivityIndicator stopAnimating];
[transactionsActivityIndicator stopAnimating];
[swipeHQCheckout showMessage:PHRASE_ServerCommunicationError];
return;
}
if ([reports count] == 0) {
[self removeReceivedDataHandle];
[transactionsActivityIndicator stopAnimating];
return;
}
SBJsonParser *parser = [[SBJsonParser alloc] init];
[reports removeObject:tag];
if ([tag isEqualToString:API_TransactionReport] ||
[tag isEqualToString:API_FetchTransactions]) {
NSMutableDictionary *dict = [parser objectWithString:[[NSString alloc] initWithData:dataForConnection encoding:NSUTF8StringEncoding] error:nil]; // here issue
NSString *response_code=[dict objectForKey:#"response_code"];
// more code down here
}
What could be the issue, advanced thanks for the suggestions.

Answer 1

It seems your NSMutableData dataForConnection is coming nil and you are initializing a NSMutableDictionary with nil value
To avoid crash :
if (dataForConnection != nil){
NSMutableDictionary *dict = [parser objectWithString:[[NSString alloc] initWithData:dataForConnection encoding:NSUTF8StringEncoding] error:nil];
}else{
NSLog(#"NO Data");
}

Answer 2

You should add the check at the start of the method to follow best practise, like
if (dataForConnection == nil){
NSLog(#"NO Data");
return;
}else{
//Do whatever you want to do
}