App Crashing if we make array with no contents

[fparkar]

I am trying to using your control and it works smoothly.

I just face one issue. Before I call my feeds data, ViewPagerController delegate are getting called. At that time I have feeds as null.

Crash I get is at below line in ViewPagerController

[self.pageViewController setViewControllers:@[viewController] direction:UIPageViewControllerNavigationDirectionForward animated:NO completion:nil];

In Log, I see below details.

2013-11-20 15:54:52.476 Garage[1517:a0b] * Terminating app due to uncaught exception 'NSInvalidArgumentException', reason: '* -[**NSPlaceholderArray initWithObjects:count:]: attempt to insert nil object from objects[0]' * First throw call stack: ( 0 CoreFoundation 0x01fa05e4 __exceptionPreprocess + 180 1 libobjc.A.dylib 0x019f48b6 objc_exception_throw + 44 2 CoreFoundation 0x01f54386 -[__NSPlaceholderArray initWithObjects:count:] + 390 3 CoreFoundation 0x01f66dc2 +[NSArray arrayWithObjects:count:] + 66 4 Garage 0x000a38ac -[ViewPagerController setActiveContentIndex:] + 316 5 Garage 0x000a5b5e -[ViewPagerController selectTabAtIndex:] + 94 6 Garage 0x000a9624 -[ViewPagerController defaultSetup] + 8660 7 Garage 0x000a0939 -[ViewPagerController viewWillAppear:] + 137 8 Garage 0x00055682 -[DirectoryViewController viewWillAppear:] + 98 9 UIKit 0x0087e28a -[UIViewController _setViewAppearState:isAnimating:] + 419 10 UIKit 0x0087e695 __52-[UIViewController _setViewAppearState:isAnimating:]_block_invoke + 325 11 CoreFoundation 0x0201d05d __53-[__NSArrayI enumerateObjectsWithOptions:usingBlock:]_block_invoke + 61 12 CoreFoundation 0x0201cf92 -[__NSArrayI enumerateObjectsWithOptions:usingBlock:] + 258 13 CoreFoundation 0x01f9a0a5 -[NSArray enumerateObjectsUsingBlock:] + 53 14 UIKit 0x0087e444 -[UIViewController _setViewAppearState:isAnimating:] + 861 15 UIKit 0x0087e798 -[UIViewController __viewWillAppear:] + 114 16 UIKit 0x0088f310 -[UIViewController(UIContainerViewControllerProtectedMethods) beginAppearanceTransition:animated:] + 199 17 UIKit 0x00894b8e -[UINavigationController _startCustomTransition:] + 1062 18 UIKit 0x008a1757 -[UINavigationController _startDeferredTransitionIfNeeded:] + 688 19 UIKit 0x008a2349 -[UINavigationController __viewWillLayoutSubviews] + 57 20 UIKit 0x009db39d -[UILayoutContainerView layoutSubviews] + 213 21 UIKit 0x007d1dd7 -[UIView(CALayerDelegate) layoutSublayersOfLayer:] + 355 22 libobjc.A.dylib 0x01a0681f -[NSObject performSelector:withObject:] + 70 23 QuartzCore 0x0043472a -[CALayer layoutSublayers] + 148 24 QuartzCore 0x00428514 _ZN2CA5Layer16layout_if_neededEPNS_11TransactionE + 380 25 QuartzCore 0x00428380 _ZN2CA5Layer28layout_and_display_if_neededEPNS_11TransactionE + 26 26 QuartzCore 0x00390156 _ZN2CA7Context18commit_transactionEPNS_11TransactionE + 294 27 QuartzCore 0x003914e1 _ZN2CA11Transaction6commitEv + 393 28 QuartzCore 0x00391bb4 _ZN2CA11Transaction17observer_callbackEP19__CFRunLoopObservermPv + 92 29 CoreFoundation 0x01f6853e __CFRUNLOOP_IS_CALLING_OUT_TO_AN_OBSERVER_CALLBACK_FUNCTION + 30 30 CoreFoundation 0x01f6848f __CFRunLoopDoObservers + 399 31 CoreFoundation 0x01f463b4 __CFRunLoopRun + 1076 32 CoreFoundation 0x01f45b33 CFRunLoopRunSpecific + 467 33 CoreFoundation 0x01f4594b CFRunLoopRunInMode + 123 34 GraphicsServices 0x02f399d7 GSEventRunModal + 192 35 GraphicsServices 0x02f397fe GSEventRun + 104 36 UIKit 0x0076794b UIApplicationMain + 1225 37 Garage 0x00026e32 main + 130 38 libdyld.dylib 0x06559725 start + 0 ) libc++abi.dylib: terminating with uncaught exception of type NSException

To test in your app, you can make below change

pragma mark - ViewPagerDataSource

• (NSUInteger)numberOfTabsForViewPager:(ViewPagerController *)viewPager { return 0; }

return 0; is the change.

Also as an future, you can add also below point (as per our email conversation).

If some tab is selected, text of that tab get's changed.

[pplant]

@fparkar a bit late but you can simply fix this issue by inserting

self.view.userInteractionEnabled = self.tabCount > 0;

under

self.tabCount = [self.dataSource numberOfTabsForViewPager:self]; in defaultSetup