I have a TabViewController setup in my iOS app with 4 tabs. Some of the tabs go to static ViewControllers while a few go to a navigation controller that the user can then dive deeper into.
My problem is this, in the app delegate, I implement the "didReceiveRemoteNotification" method, when I receive a remote notification I display a drop down notification using a library similar to this https://github.com/terryworona/TWMessageBarManager
I would like the simplest and cleanest way to add a callback to one of these drop down messages such that when clicked I display a particular index in the tab view regardless of where I am in the app.
I have thought of possibly having the app delegate broadcast a notification that the currently displayed view controller would listen too, then have the currently displayed view controller unwind if it is nested in a navigation controller to the top level, i.e. the level where the TabViewController would be displayed and then change the tab view controller's index. Or if the TabViewController was currently displayed, it would capture the notification and simply change index. But this seems conceptually intrusive because now my ViewControllers themselves must have knowledge about where they are in the UI hierarchy, and all ViewControllers (which there are many) must implement functionality to deal with the notification so they can decide to unwind + set tab index OR simply set tab index.
I would subclass the TabBarController, and you could add a method like -(void) receiveMessageBarNotification:(NSNotification*)notification. The TabBarController already has references to your view controllers and so can handle all the logic of 'navigation controller stack vs static VC'. Then it would call the unwind segue on the view controller (if necessary) and change its own index.
The notification registration could all be handled by the AppDelegate.
Related
Is it possible to launch an app to a specific level of a navigation stack using a storyboard?
I'm looking to recreate the model employed by Mail.app, where the app launches into the Inbox, but this is actually one level down the navigation stack, and tapping the back button takes you to the root...
I understand how this can be done via code, i.e. instantiating the navigation controller within the app delegate and then manually pushing the view controller(s) to create the desired stack, but I'd really like to know if there's a way to achieve the same using storyboards.
Unfortunately I don't think there is because you need to instantiate your navigation controller at some point that will house your view controllers, and if you do this through storyboards the best you can do is set the navigation controller to be the entry point.
However, it is pretty straightforward to do from code. If your navigation controller has two view controllers where ViewControllerOne pushes to ViewControllerTwo, then you can just can just push to the second one without an animation as follows:
navigationController.pushViewController(secondViewController, animated: false)
And the user will be one level deep in the navigation controller.
In my app, things start off with a registration flow, including profile creation, mobile verification, and some further customization which all happens inside separate UIViewControllers managed by a UINavigationController.
However, when registration is completed, I want to leave the UINavigationController and have my final registration View Controller segue to the main TabBarController of the application.
How can I do this?
When you are using a navigation controller that controls more than one UIViewController, you use push push segues. When you want to leave that navigation controller, you will have to use a modal segue. I'm assuming that you are using the Storyboard. When you click and drag from one UIViewController to the next, you choose modal instead of push.
Segues are useful for prototyping, but for a real app I would avoid using segues and control the display of view controllers programmatically.
In your case, you could make the TabBarController the main entry point, and then detect whether the user has registered, and if not, display the registration sequence (modally) on top of this, and when the user completes the sequence, just dismiss it and you'll be back to TabBarController.
Or you could make your initial view controller a blank screen which then decides whether to display the registration sequence or the TabBarController.
I am developing an iOS app that I have already developed for Android.
The problem is I don't know how to organize my UIViewControllers considering the following scheme of my app pages:
The scheme is simple: there is a login page which leads to the main page. From this main page, there are four buttons which all lead to a specific view hierarchy but at the very bottom of each, the user will be able to go back directly to the main page. Each page accessed by the main page will also have a custom back button (an image of my own)
The question is: is there any benefit in using a UINavigationController (obviously with the main page as its root) in my case? Or can I simply create each Controller and using only Modal Segues?
If your view controllers have a navigation relationship so using UINavigationController is the way to go:
In 'push' segue, you are basically pushing your ViewController into an
already setup "navigation stack". Well, of course, this is under the
assumption that the ViewController that performs the 'pushing'
operation belongs to the same navigation stack as the ViewController
is pushed into. Generally, you push a ViewController if the pushed
ViewController has some sort of a relationship with the pushing
ViewController. This is very common in applications that has a
NavigationController in its system. A good example for a push segue is
a system where you are displaying a list of contacts. And on tap of a
particular contact, you are pushing a VC that has the corresponding
details of the contact.
Example is real world: list of products => product details => product reviews
If you want to temporary present a view controller and the main focus is your view controller but you need to present another view controller to perform a task like "filter" , "login", adjust "settings" then modal segue is the way to go
In 'modal' segue, there is no stack as such. You are presenting a VC
'modally' over the presentee VC, if that makes sense. This can happen
across any ViewController without any relationship rules. The
presenter should take care of dismissing the VC it presented. A good
example for modal segue is login. On tap of login, you are modally
presenting a VC that has no relationship with the presenter.
If your view controllers are not related to each other, but each view controller has his own navigation stack then UITabBarController is the way to go
Storyboards (Xcode): What is the difference between a push and modal segue?
I would say if each of the additional view controllers from the main "home" view controller don't have any children view controllers, then you can just have each button present a view controller modally.
The main difference is if you are using a navigation controller, you can "pushing" a vc onto the navigation stack of view controllers, whereas presenting it modally can be thought of a "one time" action where the user does something on the new screen and has no where to advance to logically (like adding information to a new contact).
You can see this post for a more detailed answer:
What is the difference between Modal and Push segue in Storyboards?
Deciding whether to use a Modal segue vs a Show (push) depends entirely on purpose and context of the user's experience. If you are leading the user down a path which is linear, where each successive VC is diving deeper in to a singular idea, then use Show segues and NavigationControllers. Examples include, Settings app, where you can drill into all the specifics. Most e-commerce app will use a NavigationController to lead the user through a purchase.
If you want to present the user with a single concept, which the user can respond to, or close it to continue using the rest of the app. Then use a modal presentation. Adding a contact in the iPhone is a fine example of this.
Visually, the difference is that a Show segue presents the VC from the right side of the app, sliding onto the previous VC. (If the user has Arabic language turned on, a right to left language, the Show segue will come from the left hand side of the VC) A modal comes from the bottom of the app.
From looking at your drawing, but not know anything else about your app, I think you want to use NavigationControllers. You may also want to consider a TabBarController. If each of these buttons lead the user on various ways of using the app, like mini apps within one big one, then a TabBarController is appropriate.
i'm curious about what's the best way to plan the controllers for my app.
i want my main screen to have 3 button.
1) should open a nav controller with details view
2) should open a controller with other buttons that lead to others controllers
3) should open a tab bar with 2 pages ( or eventually use a switch to change page instead of the tab bar)
this is the schema of what i want
http://i59.tinypic.com/2rrvrd4.png
Is it a correct schema or i should use my controllers differently? will apple reject an apple with such schema?
thanks
As #Fogmeister pointed out in the comments, going for a UITabBarController as the main interface for your app actually seems to be a more appropriate solution here.
However, you can go with the interface that you described, but then you should keep in mind that with your current setup, you are not only using UINavigationController in the first case, but your whole navigation system is still built upon UINavigationController in the following way:
Your app has one instance of UINavigationController.
Your initial UIViewController (the one with the three buttons), is the rootViewController of your UINavigationController.
You can navigate to the other view controllers using [self.navigationController pushViewController:newViewController] (or performSegue if you prefer using Storyboards).
In the case of your third view controller, you are pushing a UITabBarController onto the navigation controller's view controller stack, this UITabBarController needs to be initialized with the two view controllers that it is going to display before it gets pushed onto the stack.
So recently I had to reorganize my tab bar and remove one the tabs for a view controller that I still need to access at the end of the app. I am using NSNotifications which triggers a method in the app delegate which basically switches the tab [self.myTabBar setSelectedIndex:REC_TAB];
Worked like a charm. Now that I can no longer select the tab, I'm finding I'm having trouble pushing/popping/presenting a view controller from the app delegate.
I'm new to this so any help would be appreciated.
There's no reason that you have to do it from the app delegate -- you can if you want to, but there's no need. From any view controller, you can access the window's root view controller with self.view.window.rootViewController, and change it to whatever you want. Another way is to just present a modal view controller with presentViewController:animated: from any view controller.