SideNavigationController - Replace rootViewController of NavigationController

Question

I'm using the Material Framework by CosmicMind. Currently I'm trying to replace the ViewController once a row is selected in the SideNavigationController. Unfortunately I can't figure out how to do this. There're similar question here on StackOverflow (#1) unfortunately the solutions don't work for me.

Following my code in the AppDelegate.swift class:

func application(application: UIApplication, didFinishLaunchingWithOptions launchOptions: [NSObject: AnyObject]?) -> Bool {

    let storyboard = UIStoryboard(name: "Main", bundle: nil)
    let myViewController = storyboard.instantiateViewControllerWithIdentifier("MyViewController")

    let navigationController: NavigationController = AppNavigationController(rootViewController: myViewController)

    let sideNavigationController: SideNavigationController = SideNavigationController(rootViewController: navigationController, leftViewController: AppLeftViewController())

    // further code

    return true
}

With this code everything works fine. The ViewController (MyViewController) is shown.
Now I'm trying to replace the MyViewController with MySecondViewController however this doesn't work. Following the code I've been using:

sideNavigationController?.transitionFromRootViewController(MySecondViewController())

The result is that the Toolbar disappears and I can't close the SideNavigationController anymore. So I've tried the following:

let navigationController: NavigationController = AppNavigationController(rootViewController: MySecondViewController())
sideNavigationController?.transitionFromRootViewController(navigationController)

With this code the Toolbar is visible once again but the problem with the SideNavigationController remains -> means: It can't be closed.

tl;dr
How do I replace the rootViewController of the NavigationController properly?

CosmicMind · Accepted Answer · 2016-04-16T03:56:52.193

1

The NavigationController is a subclass of UINavigationController. So changing the rootViewController is as iOS made it. For example:

navigationController?.pushViewController(MySecondViewController(), animated: true)

The SideNavigationController offers the ability to transition its rootViewController. This is different, as the SideNavigationController uses child UIViewControllers and swaps them when asked. For example:

sideNavigationController?.transitionFromRootViewController(MySecondViewController())

Sometimes, people use the sideNavigationController to early. For example, you instantiate a new UIViewController, and place the sideNavigationController code in the videDidLoad method. This won't work since the new UIViewController was not yet added to the sideNavigationController view hierarchy. To solve this, use the viewWillAppear method.

The last situation to consider is when you want to load a new UIViewController in the rootViewController of the NavigationController from the sideNavigationController. In order to do this, and let's consider that the sideNavigationController's rootViewController is the NavigationController, you would need to do this:

(sideNavigationController?.rootViewController as? NavigationController)?.pushViewController(MySecondViewController(), animated: true)

This should help you out :)

edited Apr 16 '16 at 03:56

answered Apr 07 '16 at 17:39

CosmicMind

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Thanks for the quick and comprehensive answer. The problem is if I use the `pushViewController` approach I end up having a "back caret" in my Toolbar and the previously visible ViewController isn't replaced but put on the backstack and that's obviously not the expected behaviour when something is selected from the SideNavigationController, isn't it? – user3420815 Apr 07 '16 at 18:19
1

Yes, I wouldn't expect that the backButton appear when an item is selected from the SideNavigationController. Here is how I would look at it. NavigationController is a subclass of UINavigationController, which is a subclass of UIViewController. This means that it is nothing more than a UIViewController at the end of the day, withs some extras for navigation. There isn't a rule that says "you cannot use multiple Navigation stacks". Meaning, if you are going to instigate a navigation flow from your SideNavigationController, it could easily launch a new NavigationController with its own stack. – CosmicMind Apr 07 '16 at 19:22
Ok so you're basically saying that I should create a new `NavigationController` with a rootViewController (e.g. *MySecondViewController*) and call `sideNavigationController?.transitionFromRootViewController(newNavController)`? – user3420815 Apr 07 '16 at 21:49
Yes :) It will also help you organize your application into modular parts. – CosmicMind Apr 08 '16 at 02:13

SideNavigationController - Replace rootViewController of NavigationController

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