iOS Crash Log NSObject doesNotRecognizeSelector: - at which line? - ios

Question

I have recorded a crash of my app, but the last line in my app (5 Control) points just to the method begin. How do I know in which line the problem is?
0 CoreFoundation 0x185f0af50 __exceptionPreprocess + 132
1 libobjc.A.dylib 0x1924141fc objc_exception_throw + 60
2 CoreFoundation 0x185f0fc04 -[NSObject(NSObject) doesNotRecognizeSelector:] + 220
3 CoreFoundation 0x185f0d930 ___forwarding___ + 912
4 CoreFoundation 0x185e2d5dc _CF_forwarding_prep_0 + 92
5 Control 0x10005acb4 -[PaymillPaymentService handleTransactionListRequest:] (PaymillPaymentService.m:211)
6 Foundation 0x186a7416c __103+[__NSOperationInternal _observeValueForKeyPath:ofObject:changeKind:oldValue:newValue:indexes:context:]_block_invoke96 + 28
7 libdispatch.dylib 0x1929ec014 _dispatch_call_block_and_release + 24
8 libdispatch.dylib 0x1929ebfd4 _dispatch_client_callout + 16
9 libdispatch.dylib 0x1929f32b8 _dispatch_root_queue_drain + 556
10 libdispatch.dylib 0x1929f34fc _dispatch_worker_thread2 + 76
11 libsystem_pthread.dylib 0x192b816bc _pthread_wqthread + 356
12 libsystem_pthread.dylib 0x192b8154c start_wqthread + 4
Here the [lengthy] method code. I see a couple of places where I can add the check but how to I know it for sure that I fixed the issue? The problem is sporadical and I cannot reproduce it easily.
- (void)handleTransactionListRequest:(ServiceRequest *)serviceRequest
{
LRURLRequestOperation* operation = serviceRequest.operation;
NSHTTPURLResponse *response = (NSHTTPURLResponse *)operation.URLResponse;
if (response.statusCode == 200)
{
if (operation.responseData)
{
NSError *parserError = nil;
NSDictionary *data = [NSJSONSerialization JSONObjectWithData:operation.responseData options:0 error:&parserError];
//NSLog(#"%#", data);
if (!parserError)
{
NSArray* transactions = [data objectForKey:#"data"];
if (0 == serviceRequest.currentOffset)
{
NSNumber* totalCountObj = [data objectForKey:#"data_count"];
serviceRequest.totalCount = [totalCountObj intValue];
}
int loadedCount = 0;
if (transactions)
{
for (id object in transactions)
{
TransactionInfo* info = [self createTransactionFrom:object];
[serviceRequest.transactionList addTransaction:info];
[info release];
loadedCount++;
}
}
if (loadedCount + serviceRequest.currentOffset >= serviceRequest.totalCount)
{
if ([serviceRequest.delegate respondsToSelector:#selector(transactionListLoadingComplete:)])
[serviceRequest.delegate transactionListLoadingComplete:serviceRequest];
serviceRequest.transactionList.timeStamp = [[NSDate date] timeIntervalSince1970];
NSLog(#"COMPLETE: %d transaction loaded ", serviceRequest.totalCount);
}
else
{
serviceRequest.currentOffset += loadedCount;
bool needToContinue = YES;
if ([serviceRequest.delegate respondsToSelector:#selector(transactionListLoadingContinue:)])
needToContinue = [serviceRequest.delegate transactionListLoadingContinue];
if (needToContinue)
{
[self continueRetrievingTransactionListFor:serviceRequest];
NSLog(#"CONTINUE: %d of %d loaded ", serviceRequest.currentOffset, serviceRequest.totalCount);
}
}
return; // all OK cases
}
}
}
if ([serviceRequest.delegate respondsToSelector:#selector(transactionListLoadingFailed:with:)])
[serviceRequest.delegate transactionListLoadingFailed:serviceRequest with:response.statusCode];
NSLog(#"ERROR: Loading Transactions Response Code: %ld", (long)response.statusCode);
}

Answer 1

Short Answer:
You are sending a message to an object that cannot validly respond to it. The stack trace is telling you that when you make the call [PaymillPaymentService handleTransactionListRequest:] that PaymillPaymentService cannot accept handleTransactionListRequest.
Long answer:
Look at the stack trace here:
5 Control 0x10005acb4 -[PaymillPaymentService handleTransactionListRequest:] (PaymillPaymentService.m:211)
This is telling you that in the file PaymillPaymentService.m on line 211 you are sending PaymillPaymentService the message handleTransactionListRequest to which it cannot validly respond. In your discussion with rmaddy, Hot Licks, and Paulc11 you mentioned that line 211 is the function entry for handleTransactionListRequest (in whatever file it resides). If that's the case it is coincidental.
If you want further follow up you need to post PaymillPaymentService.m and ensure that you include all the line numbers.