UIPageViewController with multiple views - ios

Question

I need a dynamic UIPageViewController, the number of pages depends on the quantity of items of my array.
I have two views for this. One for the first page and another one for the other pages. It will be always more than 2 pages (two items on my array).
I'm trying to test with fixed values. But the paging it's not right. The index is not correct.
1st problem, the presentationCountForPageViewController [_vc count] returns nil;
2nd problem, the pagination it's not right. I get to the last page, and the first view it's gone, so if I go back, goes to second view, always...
Please, help!
- (void)viewDidLoad {
[super viewDidLoad];
FirstViewController *agenda = (FirstViewController*)[self viewControllerAtIndex:0];
[_vc addObject:#"FirstViewController"];
[_vc addObject:#"SecondViewController"];
self.pageViewController = [self.storyboard instantiateViewControllerWithIdentifier:#"PageViewController"];
self.pageViewController.dataSource = self;
NSArray *viewControllers = [NSArray arrayWithObject:agenda];
[self.pageViewController setViewControllers:viewControllers direction:UIPageViewControllerNavigationDirectionForward animated:NO completion:nil];
[self addChildViewController:_pageViewController];
[self.view addSubview:_pageViewController.view];
[self.pageViewController didMoveToParentViewController:self];
UIPageControl *pageControlAppearance = [UIPageControl appearanceWhenContainedIn:[UIPageViewController class], nil];
pageControlAppearance.pageIndicatorTintColor = [UIColor lightGrayColor];
pageControlAppearance.currentPageIndicatorTintColor = [UIColor darkGrayColor];
}
- (UIViewController *)pageViewController:(UIPageViewController *)pageViewController viewControllerBeforeViewController:(UIViewController *)viewController
{
NSUInteger index = [_vc indexOfObject:viewController];
if ((index == 0) || (index == NSNotFound)) {
return nil;
}
index--;
//notice here I call my instantiation method again essentially duplicating work I have already done!
return [self viewControllerAtIndex:index];
}
- (UIViewController *)pageViewController:(UIPageViewController *)pageViewController viewControllerAfterViewController:(UIViewController *)viewController
{
NSUInteger index = [_vc indexOfObject:viewController];
if (index == NSNotFound) {
return nil;
}
index++;
return [self viewControllerAtIndex:index];
}
#pragma mark - Page View Controller Data Source
- (UIViewController *)viewControllerAtIndex:(NSUInteger)index
{
if (index == 0){
FirstViewController *firstController = [self.storyboard instantiateViewControllerWithIdentifier:#"FirstViewController"];
return firstController;
}
else{
SecondViewController *secondController = [self.storyboard instantiateViewControllerWithIdentifier:#"SecondViewController"];
return secondController;
}
}
- (NSInteger)presentationCountForPageViewController:(UIPageViewController *)pageViewController
{
return [_vc count];
}
- (NSInteger)presentationIndexForPageViewController:(UIPageViewController *)pageViewController
{
return 0;
}

Answer 1

As per comments/chat, a few things needed resolving:
You need to instantiate the _vc array
You need to add UIViewControllerobjects to this array, not the strings you currently use
You need to amend the viewControllerBeforeViewController and viewControllerAfterViewController methods to return the relevant element from the _vc array, remembering to test that the index remains within the array's bounds, to prevent swiping beyond the final page, or before the first (agenda) page.