UIPageViewController and different view controllers

Question

I am trying to implement a UIPageViewController. I have done this before but using the same UIViewController and changing the images etc when paging. I want to page between different UIViewController now. I'm trying to code the method that creates the UIViewController based on what is in an array that contains the storyboard ID for the UIViewControllers. For example I have this array:

self.controllerIdentifiers=[NSArray arrayWithObjects:@"ViewControllerTypeA",@"ViewControllerTypeB", nil];

Now trying to implement :

- (UIViewController *)pageViewController:(UIPageViewController *)pageViewController viewControllerBeforeViewController:(UIViewController *)viewController
{
    if (self.controllerIndex==0) return nil;

    self.controllerIndex--;
    NSString *id = self.controllerIdentifiers[self.controllerIndex];

    //If I knew the controller type I would do something like this..

    ViewControllerTypeA *typeA = [self.storyboard instantiateViewControllerWithIdentifier:@"ViewControllerTypeA"];

    return typeA;
}

The problem is I'm not sure how to tell the code what type of UIViewController it is. Do I need to case some logic for every possible index and just initiate a UIViewController that way?

possible duplicate of [How to implement UIPageViewController that utilizes multiple ViewControllers](http://stackoverflow.com/questions/21641373/how-to-implement-uipageviewcontroller-that-utilizes-multiple-viewcontrollers) — Quentin Hayot, May 25 '15 at 13:24

score 2 · Accepted Answer · edited May 23 '17 at 12:05

2

I use this template to achieve this. It comes from a (possible duplicate) question with two interesting answers that you can find there.

EDIT:
TL;DR the idea is to use storyboard identifiers for your different view controllers to instantiate them when needed, using the PageViewControllerDataSource protocol methods.

edited May 23 '17 at 12:05

Community

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answered May 25 '15 at 13:23

Quentin Hayot

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Hey, just took a look at this github example. It seems that all the UIViewControllers in this are of the class UIViewController. My UIViewControllers are all different types i.e use different class files so I'm not sure how to initiate it if i don't know its type. – Kex May 25 '15 at 13:54
It doesn't matter. Since it's instantiated from a storyboard, iOS will do the work for you. The root viewController doesn't need to be aware of the different page classes. – Quentin Hayot May 25 '15 at 13:56
would I initiate it with UIViewController *controller = [self.storyboard instantiateViewControllerWithIdentifier:@"SomeID"]; then? – Kex May 25 '15 at 13:58
Have a look at BaseContentViewController. He subclasses all his pages from it. – Quentin Hayot May 25 '15 at 14:01
Yeah, see that. Just don't get why you don't have to cast the UIViewController or anything. e.g we have UIViewController *previousViewController = [self viewControllerAtIndex:index - 1]; but the previous view controller may be a Page2ViewController class.. – Kex May 25 '15 at 14:07
You don't have to cast because you don't have to use class specific methods/properties there. Only your page's viewController needs to be aware of it's own subclass. For the rootViewController, as long as your pages are UIViewController subclasses, it doesn't matter. – Quentin Hayot May 25 '15 at 14:10
I got it now! Thanks for you help. Much appreciated. – Kex May 25 '15 at 14:16

UIPageViewController and different view controllers

1 Answers1