I'm implementing a navigation hierarchy in a storyboard. For part of my navigation, I am drilling down through a tree of data, so I have a couple view controllers in a row with the exact same look but different data management so they need separate controllers. To avoid duplication I did the layout for those views in a XIB, made a VC class for the XIB to handle setting up the views, and then I extend that class for each VC in the storyboard to handle the UITableViewDataSource stuff.
Now the navigation is working fine, but I want to have a button on the XIB views that triggers an unwind segue back to the beginning. I have the segues set up with identifiers in the storyboard from my VCs with a XIB layout to the home screen, but no matter what I do, when I call performSegueWithIdentifier I always get the has no segue with identifier error.
I think what's going on is that everything extra added to the view controller in the storyboard is removed when the XIB is loaded. I found that that was happening with my navigation item in these views and I had to create the navigation item in code since there's no way to add one in a XIB. I suspect something related is happening with the segues, but I can't figure out a workaround. Is it just not possible to have a VC in a storyboard with its layout in a XIB and then perform a segue from it? Is there a programmatic way to do an unwind segue without setting it up in the storyboard?
Unwinding is only available if you are using storyboard. So in your case you have to use UINavigationController.popViewControllerAnimated or UIViewController.dismissViewControllerAnimated:completion:.
Related
I need to navigate inside folders and files in directory (from server). The problem is that I don't know the number of folders so it's not possible to use performSegueWithIdentifier statically. How can I use navigation controller with dynamically number of view controllers in swift? I want to "push" a new view controller every time a user tap on a folder in order to list files/folders inside it and I want to do it with UINavigationController so the user have the possibility to go back with "previous" button.
Both storyboard and programmatically approaches are ok.
Thanks you
Storyboards and segues are just a crutch. Think about how you would do this without them. At each level, to go down a level, you would just instantiate a new view controller and push it onto the navigation controller stack with pushViewController:animated:.
https://developer.apple.com/library/ios/documentation/UIKit/Reference/UINavigationController_Class/#//apple_ref/occ/instm/UINavigationController/pushViewController:animated:
And in fact it takes only one view controller class to do this, since any instance can create and push another instance of its own class. The display of one folder is exactly like the display of any other.
So if you wanted to configure this notion in a storyboard, you would have a circular segue, that is, the view controller would have a push / show segue leading to itself.
I agree with #matt's answer, just create the controller and push it. For sake of completeness, you can do this in a Storyboard with a segue.
Here's how:
So that you can call the segue programmatically, add an additional prototype cell to your tableView. (You do this because you don't want the segue to be automatically triggered when the tableViewCell is selected. By using an additional prototype cell, the segue can be wired up, but it will never be triggered automatically since this prototype cell will never actually be instantiated.)
Control-drag from this prototype cell to the viewController icon at the top of the tableViewController. Select "Show" from the pop-up.
Find this segue in the Document Outline View and give it an identifier such as "showFolderSegue" in the Attributes Inspector.
Now, when you want to trigger the segue, call: self.performSegueWithIdentifier("showFolderSegue", sender: self)
You can use prepareForSegue to set up the new tableViewController as you normally would.
This method too works with a single tableViewController.
I have a ProductDescription ViewController that gets called from a ProductTable UITableView that I have placed in many ViewControllers.
It doesn't seem very efficient to ctrl+drag a segue for each tableView in the Storyboard, as I have approx 20 of them.
How does one do this programmatically?
You have several options within UIKit to programmatically show a view controller without using a segue:
Push a view controller onto the navigation stack:
pushViewController:animated:
showViewController:sender:
Present a view controller modally:
presentViewController:animated:completion:
The real answer here is to use storyboard references. You shouldn't have the same thing in twenty different spots all trying to link to the same view controller to the point of asking this question.
So, let's create Product.storyboard, a storyboard which simply has two view controllers:
ProductTableViewController
ProductDescriptionViewController
And the appropriate segue between the two controllers.
Now, everywhere else in any of your other storyboards that want to use these controllers with this relationship, simply add a storyboard reference, add a container view controller, and add an embed segue between the container view and the appropriate view controller in the product storyboard.
You can accomplish this same effect even without using storyboard references. Ultimately, the main point is to use container views and make embed segues from everywhere you need this relationship to the first of these two controllers, and then there's just a single relationship created between the two product view controllers.
I know there is the common practice in iOS development of having one UIViewController presented on the screen whose view is loaded from a XIB which will contain all the UIView subclasses in it.
While I was working on a pretty complex widget for an app, I decided to make the widget subclass a UIViewController instead of a UIView. This was because I thought a UIViewController was essentially a UIView with some helper methods around it. Then I could create a XIB for it (I know UIViews can have their own XIBs too), load the views it contains, place ITS view in the presented parent VC's view, and lay it out.
This works fine so far, but I'm wondering if this is bad practice and if I should just subclass a UIView instead and give it a normal NSObject controller. I am seeing some problems with this and I was wondering if anybody could address concerns I have with this approach?
EDIT NOTE: The widget VC does NOT relate to the VC view it is in and is reusable on ANY screen. So the answer is not subclassing the widget VC with the parent VC. The widget is INSIDE the parent VC, but it is NOT a parent VC.
EDIT NOTE 2: I am NOT using Storyboard. Only Autolayout, XIBs, and ARC.
Why can't we have VC's in VC's?
1) Can VC's be simply dropped into ANOTHER VC's XIB and be loaded easily as a subview?
2) I read here: When to use a UIView vs. a UIViewController on the iPhone?
The top answer explains how the VC controls rotation of the screen and laying out the subviews again, so if you add another VC, then the system will automatically think that THAT is the main VC and will attempt to rotate it instead, causing problems. Is this true? Or is he just talking about if you somehow got into a state where 2 VC's were "presented"? I wasn't sure if his answer applied to VC views that were SUBVIEWS of other VC views.
3) In general is this good practice? It certainly seemed more reasonable as it made loading the subview VC's view much easier.
Thanks!
It's absolutely fine. The answer to your problem is ContainerView.
Container View defines a region within a view controller's view subgraph that can include a child view controller. Create an embed segue from the container view to the child view controller in the storyboard.
You almost got it right. Yes, it's good to make a view controller for what you needed. But you shouldn't just add it's view to the parent view, you should also add the view controller as a child view controller of the first view.
You can add many views controllers as child view controllers of a view controller.
You can learn more about this here.
I have a storyboard that uses a UITabBarController with 3 tabs.
I want to use SWRevealViewController to add the sliding menu functionality.
Opening the menu will slide the hole UITabBarController.
Did anyone managed to implement this kind of behaviour with storyboards UITabBarController and SWRevealViewController?
Thank you
Managed to integrate it. Below are the steps to do it:
Add a new UIViewController to the storyboard.
Remove the content view from the newly added UIViewController
Make sure "Is Initial View Controller" is checked in IB for the newly added UIViewController
Set the custom class for the newly added UIViewController to SWRevealViewController
Connect it to a view controller that you intend to be the rear view controller - give the segue "sw_rear" identifier in IB. This must be a reveal controller segue type.
Connect it to the UITabBarController - give the segue "sw_front" identifier in IB. This must be a reveal controller segue type.
You should use a navigation controller before tab bar controller(sw_front > navigation controller > tab bar controller).
gfdx answered his own question, but make sure to also look at this tutorial for more insight on how to hook up everything else correctly.
Because I'm using Core Data and I was told that calling
[[NSApp delegate]managedObjectContext];
is not a good idea, I pass in my data controller class to the views in AppDelegate.m. Since I'm now using the SWRevealViewController instead of my subclass of UITabBarController, I had to make some modifications.
SWRevealViewController performs some interesting behaviors on load, one of which is loading the dependent view controllers by calling the segues. Be aware that if you make changes in your subclassed prepareForSegue:sender: method, make sure to always, always call the super's method, otherwise you'll end up with a black, blank application.
I have a storyboard with a navigation controller that leads to an UIVIewController that I want to reuse. That UIVIewController has a ParentUIViewController that has all the basic functionalities for all the UIVIewControllers that I am reusing.
Currently I am copying and pasting (meh) and then I change the class of the UIViewController to the ChildUIVIewController that I want to use (ChildUIViewController extends ParentUIViewController).
But this sounds like a bad solution. Everytime I want to change the ParentViewController visually I need to update, manually, all other ChildViewControllers.
I have tried to create a xib for the ParentViewController but the xib isn't loaded because I need a xib with the name of the ChildViewController. I have created it and then said the class is the ParentViewController but it crashes in the segue.
EDIT
I have created an example of the status of my problem
https://github.com/tiagoalmeida/storyboardexample
Note that the ParentViewController has a set of logic way more complicated that is not illustrated there. Also note that I am also using a TableView. I hope that this can illustrate the problem.
Keep the logic on the parentViewController and the UI Part on the child UIViewControllers. If you need to create a new UIViewController, you will create a child that will have a corresponding XIB (or get rid of XIBs and create the interface by hand).
Have you considered looping back into the same UIViewController via a "phantom button"?
Have a look at this: UIStoryboard Power Drill, Batteries included
Essentially you can drag a Bar Button Item into the little black bar under the View Controller in Storyboard (the 1 with View Controller, First Responder, and Exit icons; sorry, I don't recall what this is called exactly), then you can control+drag from that button back into the UIViewController for a Push segue. This should create a loop segue in your Storyboard. All you need to do next is give that segue an identifier, programmatically call it from your code using [self performSegueWithIdentifier:], then implement -(void)prepareForSegue: and use [segue destinationViewController] to conditionally set the title and perhaps some flags so you can identify when to use different kinds of fetches (or other code variations) in the same Class code.