What is the difference between Modal and Push segue in Storyboards? - ios

Can someone explain to me what is the exact difference between modal and push segue?
I know that when we use push the segue gets added to a stack, so when we keep using push it keeps occupying memory?
Can someone please show me how these two are implemented?
Modal segues can be created by simply ctrl-click and dragging to destination but when I do that with the push my app crashes.
I am pushing from a button to a UINavigationController that has a UIViewController.

A push Segue is adding another VC to the navigation stack. This assumes that VC that originates the push is part of the same navigation controller that the VC that is being added to the stack belongs to. Memory management is not an issue with navigation controllers and a deep stack. As long as you are taking care of objects you might be passing from one VC to another, the runtime will take care of the navigation stack. See the image for a visual indication:
A modal Segue is just one VC presenting another VC modally. The VCs don't have to be part of a navigation controller and the VC being presented modally is generally considered to be a "child" of the presenting (parent) VC. The modally presented VC is usually sans any navigation bars or tab bars. The presenting VC is also responsible for dismissing the modal VC it created and presented.

Swift 3.0 and XCode 8.2.1 update
1. Push Segue
Push segue has been renamed as Show segue. To create push segue, the parent view controller needs to be embedded in navigation controller. The navigation controller provides navigation bar. Once you connect two view controller with push segue, the child view controller will automatically has navigation bar on top. The child view controller will be added on top of the navigation stack.
Push segue also provides default features. The child view controller will have a back button that gets you back to the parent view controller. You can also swipe right to pop the child view controller. The animation for push segue is like sliding pages horizontally.
While you are allowed to make a push segue from a view controller that is not in a navigation controller, you will lose all the features like navigation bar, animation, gesture etc when you do so. In this case, you should embed your parent view controller inside navigation view controller first and then make push segue to child view controllers.
2. Modal Segue
A modal segue (i.e. present modally), on the other hand, is presenting over the current view controller. The child view controller will not inherit navigation view controller so the navigation bar will be lost if you present modal segue from a view controller with navigation view controller. You have to embed the child view controller in navigation controller again and start a brand new navigation stack if you want it back. If you want to get back to parent view controller, you have to implement this by yourself and call dismiss from code.
Animation for modal segue is that the child view controller will comes up from the bottom of the page. The navigation view controller is also gone in this demo

The push view must be built in a navigationController.
Click on your master view, then in the menu bar choose:
EDITOR->embed in->navigationController

This is pushing controls using custom push and segue methods for storyboard
And Modal is way to navigate through views without using Storyboards.

Related

Navigation bar is empty, created from storyboard

This is my story board:
Whenever I jump to a view controller embedded in navigation controller, the navigation bar is shown but empty, why?
The sequence I created it is:
connect buttons with destination view controllers
embed destination view controllers in navigation view controller
And the segue I use is present modally - cross dissolve.
The First root controllers of a navigation controller won't have any Back button attached to its navigation bar. You should add an additional View Controller next to any root View Controller of Navigation Controller with Push Segue ( or Show Segue for newer IOS ) to navigate between them.
I tested different segue transition methods with test projects, the answer I got is: if you are transitioning by presenting it modally, you don't get the back button, you only get it by push.

Segue from one view controller embedded within UINavigationController to another UINavigationController

I have a UINavigationController as my root controller, but then I segue from one view controller to another UINavigationController.
But when segueing from one view controller which is embedded within a UINavigationController to another UINavigationController the push segue comes from the bottom, presuming it is segueing as a popover. I tried using a show detail segue but still not luck.
Why is this occurring and how can I segue from one to the other using a push/replace segue ?
PS: Is this happening because the UINavigationControllers conflict and overrides the segue as a popover ? The reason I am using two separate navigation controllers is because the style from the previous view overrides the style of the detail view, i posted a separate question about that Cannot change style of UINavigationBar when using scrollViewDidScroll on separate View Controller
Push segue occurs only within one navigation controller. It's how it implements 'show' type segue. Making 'show' segue from navigation controller to another navigation controller is not what Xcode drawing tool considered as 'pushing'. It interprets it as popover by default.

If I have a UITabBarController, how can I pop back to the initial view controller in a tab?

I have a UITabBarController with three tabs. I want to programmatically put the first tab back to its initial view controller. It uses a navigation controller to have hierarchical navigation.
My issue is that I can't simply call popToRootViewController on tabBarController.viewControllers[0] as that view controller could have modally presented more navigation controllers, where it would only bring back to the original modal. At which point I'd need to call dismissViewController, then popToRootViewController again an unknown amount of times.
Is there a way to more or less say tabBarController.popAllViewControllers?

iOS Storyboard Presenting Segues "relationship, embed, push, modal, custom" types

I have a basic idea what push and modal segues do. Push is used for Navigation Controller segues and Modal is the default one I've been using so far for a basic segue into another View Controller. I assume "modal" means nothing else can be going on/interrupting the segue?
Custom segues I guess are the most flexible/customizable/animatable.
I have no idea what "relationship" and "embed" segues do. Please let me know!
Thank you.
A "relationship" segue is the segue between a container view controller and its child or children -- so, the initial controller of a navigation controller, the view controllers in the tabs of a tab bar controller, and the master and detail controllers of a split view controller.
An "embed" segue is the segue between a container view and the controller that's embedded in that container view that you get automatically when you add a container view to a controller's view.
Both of these segues are executed as soon as the parent controller gets instantiated. You do not call them, but you can implement prepareForSegue, and pass information to the destination view controller.

Push segue from a view controller controlled by UITabBarController

Let's assume that a first view controller is connected with a UITabBarController and I want to make a push segue to the second view controller from this first view controller.
From my googling, it seems that a modal segue from a view controller connected with a UITabBarController hides the bottom tab bar, while a push segue doesn't.
However, my push segue is also hiding my tab bar in the second view controller. I have overridden prepareForSegue method in the first view controller.
Below are images of my storybard and the simulator. Anyone has an idea why this is the case? Thank you in advance for your helps.
Your trouble is because your tabViewController is embedded in the navigation stack that you initialise with your login screen.
you need to rearrange things so that each of your tab bar controller tabs opens to a new navigation stack.
What I suggest
your loginscreen should navigate to your tab bar controller with a modal/presenting segue, not a push segue. Remove the navController that encloses the loginscreen, you don't need it (well, even if you keep it, don't use a push segue, use a modal segue, and you won't then be referring back to that navController's viewController stack from inside your tab bar).
embed each of the first viewControllers in your tabViewCOntroller inside a separate navController.
Now you can push segue within your tabViewController's tabs.

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