Fixing Apple's UIPageViewControllerDatasource mess

gistfile1.m

-(BOOL)gestureRecognizerShouldBegin:(UIGestureRecognizer *)gestureRecognizer{
    if ([gestureRecognizer isKindOfClass:[UIPanGestureRecognizer class]]){

        NSLog(@"Velocity: %f",[(UIPanGestureRecognizer*)gestureRecognizer velocityInView:self.pageViewController.view].x);
        
        if ([(UIPanGestureRecognizer*)gestureRecognizer velocityInView:self.pageViewController.view].x > 0.0) {
                return [self isThereAPrevArticle];
        }
        else if ([(UIPanGestureRecognizer*)gestureRecognizer velocityInView:self.pageViewController.view].x < 0.0) {
                return [self isThereANextArticle];
        }
    }
    
    return YES;
}