Segue between UIViewControllers without Storyboard OR XIB - objective-c

Question

I have a nifty project I downloaded from GitHub (here) and I am playing around with it. The project has no storyboard or xibs whatsoever, and only one viewController, which is defined with just a viewController.h file and a viewController.m file.
Perhaps a noob question, but can I have viewController1.h/m programmatically segue to viewController2.h/m without using ANY xibs or storyboards? I found a lot of code on SO and elsewhere allowing one to segue programmatically from one view to another within a Storyboard, from one xib to another or from a scoreboard to a xib (though not the opposite) but nothing on how to segue from one totally code-based vc to another. All the code I found requires that you define the view in terms of the bundle location of the storyboard or xib file, but I want to use neither.
Note: I accepted the answer I did because of its ingenuity/interesting-ness, but for the sake of simplicity I personally ended up opting with this answer to the same question (mine was a duplicate it appears): iOS: present view controller programmaticallly

Answer 1

You can use [viewController presentViewController:anotherController animated:YES completion:nil]; to present the view controller modally.
Another alternative is to use a UINavigationController and do [viewController.navigationController pushViewController:anotherController animated:YES];
The second method will only work if viewController is in the stack of a navigationController

Answer 2

Here is my Context class which changes view controllers. It works with either your own view classes or storyboard view classes.
Specific to your question look at the open function. If there is no root controller when I call open, I assign it as the root view controller. Otherwise I present it from the root view controller.
import Foundation
import UIKit
private let _StoryBoard = UIStoryboard(name: "Main", bundle: nil)
private let _RootWindow = UIWindow(frame: UIScreen.mainScreen().bounds)
public var ROOT_VIEW_CONTROLLER:UIViewController = C_RootViewController()
//abstract base of context classes
class Context:NSObject
{
class var STORYBOARD:UIStoryboard
{
return _StoryBoard
}
class var ROOTWINDOW:UIWindow
{
return _RootWindow
}
var _currentController:Controller!
class func reassignRootViewController(controller:UIViewController)
{
Context.ROOTWINDOW.rootViewController = controller
ROOT_VIEW_CONTROLLER = controller
}
func initController(controllerName:String)->Controller
{
return Context.STORYBOARD.instantiateViewControllerWithIdentifier(controllerName) as Controller
}
func initControllerFromStoryboard(storyboardName:String,controllerName:String)->Controller
{
var storyboard:UIStoryboard = UIStoryboard(name: storyboardName, bundle: nil)
return storyboard.instantiateViewControllerWithIdentifier(controllerName) as Controller
}
func open(controller:UIViewController)
{
if(Context.ROOTWINDOW.rootViewController == nil)
{
Context.ROOTWINDOW.rootViewController = ROOT_VIEW_CONTROLLER
Context.ROOTWINDOW.makeKeyAndVisible()
}
ROOT_VIEW_CONTROLLER.presentViewController(controller, animated: true, completion: {})
}
func close(controller:UIViewController)
{
ROOT_VIEW_CONTROLLER.dismissViewControllerAnimated(true, completion: nil)
}
}