Modal View Disappears when using Custom transition - ios

Question

I'm trying to build a custom transition in iOS 7. The transition occurs fine, but then when transition context complete transition the modal screen disappears from the view entirely. I've followed several tutorials and I don't see what I am doing wrong. In addition, if I don't call "complete transition" then the view stays, but will not receive any touch events. I checked in Reveal App and there is no view sitting on top of it. Any ideas?
Here is the method where I initiate the transition
- (IBAction)settingsButtonClicked:(id)sender
{
UINavigationController *navigationController =[[self storyboard] instantiateViewControllerWithIdentifier:#"SettingsNavigationViewController"];
navigationController.transitioningDelegate = self;
[self presentViewController:navigationController animated:YES completion:nil];
}
Here is the code for the custom transition:
- (void)animateTransition:(id<UIViewControllerContextTransitioning>)transitionContext
{
UIViewController *fromViewController = [transitionContext viewControllerForKey:UITransitionContextFromViewControllerKey];
UIViewController *toViewController = [transitionContext viewControllerForKey:UITransitionContextToViewControllerKey];
UIView *containerView = [transitionContext containerView];
[containerView addSubview:toViewController.view];
CGRect sourceRect = [transitionContext initialFrameForViewController:fromViewController];
CGRect initialTargetFrame = [transitionContext initialFrameForViewController:toViewController];
CGRect initialFrame = CGRectMake(sourceRect.size.width + initialTargetFrame.size.width, 0, initialTargetFrame.size.width, initialTargetFrame.size.height);
CGPoint destinationPoint = CGPointMake(sourceRect.size.width - 500, 0);
CGAffineTransform translate = CGAffineTransformMakeTranslation(initialFrame.origin.x, initialFrame.origin.y);
toViewController.view.transform = translate;
[UIView animateWithDuration:PRESENT_DURATION delay:0 options:UIViewAnimationOptionCurveEaseOut
animations:^{
toViewController.view.transform = CGAffineTransformMakeTranslation(destinationPoint.x, destinationPoint.y);
}
completion:^(BOOL completed) {
if (completed) {
[transitionContext completeTransition:!transitionContext.transitionWasCancelled];
}
}];
}

Answer 1

So I found out what I was doing wrong. I was changing the modalPresentationStyle to custom on the view controller that was being popped onto the navigation controller when I should have been setting it on the navigation controller itself. I added this line to the settingsButtonClicked method above and it worked properly.
navigationController.modalPresentationStyle = UIModalPresentationCustom;