Unable to explicitly load view controller from storyboard - ios

I'm loading a view controller from a story board explicitly and have this code:
UIStoryboard *storyboard = [UIStoryboard storyboardWithName:#"Storyboard" bundle:nil];
UIViewController *initViewController = [storyboard instantiateViewControllerWithIdentifier:#"InitialScreen"];
But am getting an error "'Storyboard () doesn't contain a view controller with identifier 'InitialScreen'"
Yet as can be seen from the screenshot, the view controller does have that identifier. I've used this identical way of loading controllers before successfully, but no idea why its not working this time. Any ideas what the issue could be?

I've just found the problem - its an issue with the simulator, I could find absolutely nothing wrong with my code and was 100% sure it was ok, when I've been in that situation in the past I usually find the culprit is Xcode itself. So even though I'd cleaned and rebuilt multiple times I decided to try resetting the contents in the simulator - and bingo it started working. I put it down to a bug in the simulator caching content and not updating to reflect changes made in IB.

Does your storyboard name match the name of the storyboard file you're trying to load the view controller from? Usually the storyboards are named something like MainStoryboard_iPhone
UIStoryboard *storyboard = [UIStoryboard storyboardWithName:#"MainStoryboard_iPhone" bundle:nil];
You should also check to be sure that there are no trailing spaces in the Storyboard ID textfield. Other than that everything else looks like it should work to me.

Related

Scenes - Use dedicated Storyboards depending iPad or iPhone

Apple now wants us to use "scenes" rather than windows and screens to display content in for iPad and iPhone. Now having added the support for scenes I seem to have lost the ability to target iPad or iPhone with Storyboards?
I set my scenes inside plist like this:
This was copied from a new project, as Apple seems to have forgotten to document how to add scenes to an existing app. Another example of Apple not documenting sufficiently!
Now I seem to have lost the ability to use different storyboards for iPad from iPhone.
Whilst I could use the same storyboard for the iPad that I use with the iPhone my app looks better with the dedicated interface I have for the iPad because I use the extra real estate it offers to give a better end user experience. iPhone is fine, the interface is best suited to a small display but looks barren on an iPad.
Help!
Now I seem to have lost the ability to use different storyboards for iPad from iPhone
It's quite simple (and, as you say, not documented). You need two completely separate scene manifest entries in your Info.plist, i.e. UIApplicationSceneManifest and UIApplicationSceneManifest~ipad. They just specify different UISceneStoryboardFile values, and you're all set just as before scenes came along.
There may be a better way to do this, but searching I couldn't see anybody else covering this. Therefore, I'm giving my solution which has been accepted by the App Store here for others to review, use, improve upon, and most importantly, not waste any time on a goose chase looking for a solution that may not exist!
The way I got around this was to add another storyboard and view controller just to handle the decision if it's a iPhone or iPad, and then immediately load up the targeted storyboard. I called this "entry decision". The only issue was when closing the subsequent views you have to ensure that you're doing it correctly or you'll end up back at the "entry decision". And with a blank view, your end user could be stuck. Therefore, to ensure a user can never really be stuck I put buttons in that view so they can manually navigate should it show up if there's a change by Apple further down the line that we don't know about. Best to cover it now.
Step 1, create an new storyboard, "entry decision":
Because I'm a nice person I explain to the user it's an error and apologise. I also give them two buttons, iPad and iPhone. In theory, if all goes well, the end user will never see this, but at no cost to us it's better to cover this possibility.
Step 2, as soon as the view controller is loading get it to move to the right storyboards we actually want.
-(void)viewDidLoad {
// Need to decide which storyboard is suitable for this particular method.
// Loading from class: https://stackoverflow.com/questions/9896406/how-can-i-load-storyboard-programmatically-from-class
if ( [UIDevice currentDevice].userInterfaceIdiom == UIUserInterfaceIdiomPad )
{
UIStoryboard *storyboard = [UIStoryboard storyboardWithName:#"MainStoryboard_iPad" bundle:nil];
ViewController *detailViewController = [storyboard instantiateViewControllerWithIdentifier:#"myViewController"];
[self.navigationController pushViewController:detailViewController animated:YES];
}
else
{
UIStoryboard *storyboard = [UIStoryboard storyboardWithName:#"MainStoryboard" bundle:nil];
ViewController *detailViewController = [storyboard instantiateViewControllerWithIdentifier:#"myViewController"];
[self.navigationController pushViewController:detailViewController animated:YES];
}
}
- (IBAction)pickediPhone:(id)sender {
UIStoryboard *storyboard = [UIStoryboard storyboardWithName:#"MainStoryboard" bundle:nil];
ViewController *detailViewController = [storyboard instantiateViewControllerWithIdentifier:#"myViewController"];
[self.navigationController pushViewController:detailViewController animated:YES];
}
- (IBAction)pickediPad:(id)sender {
UIStoryboard *storyboard = [UIStoryboard storyboardWithName:#"MainStoryboard_iPad" bundle:nil];
ViewController *detailViewController = [storyboard instantiateViewControllerWithIdentifier:#"myViewController"];
[self.navigationController pushViewController:detailViewController animated:YES];
}
There's nothing really special about this as it is a mix of detecting which device and then loading the right storyboards. And for full disclosure, I include a reference back to the original code I used for loading those storyboards.
The additional two methods are just the button presses, shown here for completeness.
Step 3, update the scene configuration inside plist to target Entry Decision instead of Main.
You're targeting a different storyboard, hence this needs updated.
Step 4, returning back to your main screen.
In my app, I have a welcome screen, and then table views or other views depending on which it is. Some types work find without any issues, but as I'm using a navigational controller I need to return correctly. Therefore, this one works best for the final "back" command to the main screen:
[self.navigationController popViewControllerAnimated:YES];
Other options either went back to the Entry Decision (the fault we covered just in case) or did nothing:
[self.navigationController popToRootViewControllerAnimated:YES];
[self dismissViewControllerAnimated:YES completion:NULL];
And that is how I'm able to use my existing storyboards, which have been tweaked perfectly for iPhone and iPad over the years of this app's life, and still be able to support Apple's desire to move to scenes. My app needed to use scenes for another purpose, therefore I had no option but to go this route. I went through many attempts to try and trap the scenes as they're getting loaded, but the initial scene seems to get loaded without you, the programmer, getting any options in how it should be or which one to use. You need this pre-view controller to give you that functionality back, and it is one solution which is active in the App Store now.
Be nice.

Unit Testing Initialising storyboard

There are quite a few resources on unit testing whether just purely logical or application level, I am currently working trying to test a UITableViewCell that has IBOutlets within a storyboard and as a few posts have confirmed if i wish to instantiate the storyboard and then the view controller that contains the cell. So you have to go through a few steps to make sure the storyboard and following elements load properly with their IBOutlets like so
UIStoryboard *storyboard = [UIStoryboard storyboardWithName:#"Main" bundle:nil];
self.vc = [storyboard instantiateViewControllerWithIdentifier:#"testTableViewController"];
[self.vc performSelectorOnMainThread:#selector(loadView) withObject:nil waitUntilDone:YES];
followed by this code to get a UITableViewCell from the UITableViewController
[self.vc setTableViewData:#[#1].mutableCopy];
[self.vc.tableView reloadData];
[self.vc.tableView layoutIfNeeded];
SUT = [self.vc.tableView dequeueReusableCellWithIdentifier:#"More Menu Cell"
forIndexPath:[NSIndexPath indexPathForRow:0 inSection:0]];
and this produces a cell however for me the first breakpoint i have inside the system under test, seems to indicate that the IBOutlets have loaded, however when i actually go to assert anything, they all of a sudden disappear one me...
either references are disappearing for no reason or I'm doing something wrong.
So I have made a few discoveries which i will share here, one of them was a solution to my issue whereas originally this question was one small symptom I was attempting to fix of a larger problem.
The larger problem was, I was testing some UITableViewCells, but unfortunately their IBOutlets which where connected from the storyboard where always nil, which led me to attempt messing with how the system under test should be initialised.
I also found mixed results for using [self.vc performSelectorOnMainThread:#selector(loadView) withObject:nil waitUntilDone:YES]; as sometimes i would still have to call view or viewDidLoad for it to initialise properly. So then i did away with it entirely nd just call view and it seems to work fine.
However my cells still had nil outlets, despite my changes above. After rummaging around the internet a bit i discovered that, you should only be using [self.tableView registerClass:[MyTableViewCell class]forCellReuseIdentifier:#"MytableViewcell"]; if it hasent been created created in a storyboard as a prototype cell. It looks like it already does this for you and attempting to do it again breaks the IBOutlets.
Another small discovery was attempting to test a UIViewController of mine by setting it up like such
MyViewController *SUT = [MyViewController new];
[SUT view];
now although this initialises, again there seems to be some missing steps since this class exists in the storyboard, therefore i recommend the following
UIStoryboard *storyboard = [UIStoryboard storyboardWithName:#"Main" bundle:nil];
SUT = [storyboard instantiateViewControllerWithIdentifier:#"My Table VC"];
[SUT view];

Xcode is very laggy with lots of View Controllers

My project contains over 60 View Controllers and Xcode is very laggy when loading the storyboard.
How can I resolve this without switching to xibs? I am using Xcode 5.1 and iOS 7.x
Problem
Putting all of your ViewControllers in one Storyboard will significantly slow down Xcode (which renders XML to show your ViewControllers) if the number of the ViewControllers is above 10. Storyboard is not the place to put all of your views, because as its name suggests a board of a specific story.
Solution
Make multiple Storyboards with 5 or 6 ViewControllers each, where you can avoid rendering hell of multiple ViewControllers. You can divide your Application on different boards named by group functionality like LoginStoryboard, UserProfileStoryboard, etc.
You can instantiate a storyboard and present a specific controller by the code below:
UIStoryboard *storyBoard = [UIStoryboard storyboardWithName:#"Your Storyboard Name" bundle:nil];
UIViewController *viewController = [storyBoard instantiateViewControllerWithIdentifier:#"Your Controller ID"];
[self presentViewController:viewController animated:true completion:nil];
Keep views in more than one storyboard. It's not the problem if not every controllers are connected with segues. There is no good way to keep a large number of views in a storyboard, in addition to working on a better computer.

iOS iPad storyboard is not being selected

It seems that Xcode 5 is not choosing to use my iPad storyboard for the iPad device even though i specified it.
This is how i told Xcode 5 to use iPad storyboard:
I went to project settings under General
Selected Devices: Universal
Then i clicked on iPad
And wrote MainStoryboard-iPad.storyboard in Main Interface
But for some reason even though i make changes to my MainStoryboard-iPad storyboard its not being showed when i try to run it on an iPad.
I only have two storyboards in my project
MainStoryboard-iPad.storyboard
and
MainStoryboard.storyboard
Any ideas what could be wrong here?
Oh by the way, when i selected Universal the first time i got a box asking me something about copying (i never read it that carefully). I just hit Yes. Not sure what that box actually did.
EDIT
Code that runs in my AppDelegate.m
- (void)applicationDidBecomeActive:(UIApplication *)application {
AppDelegate *app = [[UIApplication sharedApplication] delegate];
UIStoryboard *storyboard = [UIStoryboard storyboardWithName:#"MainStoryboard" bundle:nil];
UIViewController *ivc = [storyboard instantiateViewControllerWithIdentifier:#"mainStoryBoard"];
UINavigationController *nvc = (UINavigationController*)self.window.rootViewController;
app.window.rootViewController = ivc;
}
I just encountered this a while ago.
These are the steps you need to do:
make sure the "Deployment Info" -> Devices is "Universal"
Create a storyboard for iPad (e.g) MainStoryboard_iPad.storyboard
now go to your Infor.plist
add row for "Main storyboard file base name (iPad)" and use MainStoryboard_iPad as the value of the string
Now you are good to go!
Your code is overriding the default storyboard for the device type. You are grabbing MainStoryboard, instantiating a view controller from it and setting it as the root. This is normally handled by the storyboard itself. It uses the view controller that you have picked as the root. Try removing all of that code to manually set the storyboard.
Check this project on github for an example of storyboard switching without code: https://github.com/danielmackenzie/StoryboardSelection
Xcode project points to each storyboard per device type and the appropriate board is automatically chosen on launch.
You'll need an entry for the iPad in your app's info.plist
Look in your Supporting Files group for the info.plist for your app.
You'll see an entry for the iPhone's storyboard, but not one for the iPad.
The iPhone entry should look like this:
Main storyboard file base name
and it should have the name of your iPhone's storyboard (sans file extension) as the string value for it. Something like this:
iPhone-Storyboard
Add a new entry into the pList and enter this string as the key:
Main storyboard file base name (iPad)
Make sure the data type is string.
You can now select the iPad storyboard that you want from the app's General Settings on your Target.
I JUST ran into this as well and thought you'd like a clear explanation and solution.
Sometimes, Xcode is rather maddening, isn't it? Hope this helps.
// Override point for customization after application launch.
if (<your implementation>) {
UIStoryboard *mainStoryboard = [UIStoryboard storyboardWithName:#"Main"
bundle: nil];
YourViewController *yourController = (YourViewController *)[mainStoryboard
instantiateViewControllerWithIdentifier:#"YourViewControllerID"];
self.window.rootViewController = yourController;
}
return YES;
Your logic is not taking into account your device. AFAIK, there is no method that looks at your naming postfix ("-iPad") and automatically selects the right storyboard file.
To fix it, simply replace the call to instantiate your storyboard with some logic to pick the right one based on device.
UIStoryboard* storyboard;
if (UI_USER_INTERFACE_IDIOM() == UIUserInterfaceIdiomPad)
{
storyboard = [UIStoryboard storyboardWithName:#"MainStoryboard-iPad" bundle:nil];
} else
{
storyboard = [UIStoryboard storyboardWithName:#"MainStoryboard" bundle:nil];
}

How to load a scene in a storyboard from a view controller

I am developing an application that loads a web page (using UIWebView) using Storyboard (I do know nothing about previous xib neither). I have already created a view controller for that UIWebView and everything works fine. The thing is: since previous versions of iOS don't allow to upload files, I need to make a new view (scene I thought it is called) that allows the user to pick and post a picture. I am able to develop both views separately and they work as expected but now I need to connect them based on event triggered when user wants to post a picture to the server. Using shouldStartLoadWithRequest I can catch that action, then I need to redirect to new view (which contains image picker and a button in order to upload the selected image) if iOS version is below 6.0 but I am really lost when it comes to load the new controller to show that view. Using buttons it is trivial but I don't know how to called inside the code. So far, I have a view controller linked to that scene and I have tried these ways:
WritePostViewController *postViewController = [[WritePostViewController alloc] init];
[self.navigationController pushViewController:postViewController animated:YES];
And even calling the storybard:
UIStoryboard *sb = [UIStoryboard storyboardWithName:#"MainStoryboard" bundle:nil];
[sb instantiateInitialViewController];
UIViewController *vc = [sb instantiateViewControllerWithIdentifier:#"WritePostView"];
vc.modalTransitionStyle = UIModalTransitionStyleFlipHorizontal;
[self presentViewController:vc animated:YES completion:NULL];
The first approach does nothing and second one shows this error log:
* WebKit discarded an uncaught exception in the webView:decidePolicyForNavigationAction:request:frame:decisionListener: delegate: Storyboard () doesn't contain a view controller with identifier 'WritePostView'*
I have been browsing and reading a lot but nothing solves my problem. For sure this a problem with my not-so-large knowledge about iOS but I am really stuck. I will thank any help.
By the way, I need to come back after posting the file but I could imagine it is the same way opposite direction, right?
If your code is inside a view controller (which it seems to be), you can get the current storyboard with self.storyboard. You also don't need instantiateInitialViewController because, if all your UI is coming from the same storyboard, it has already gone through the loading of the initial controller.
As for the actual error, it's complaining that #"WritePostView" isn't a recognized name for any view controller in the storyboard. Note that what it looks for here is not the class name for the controller but the Storyboard ID for the controller. (Which makes sense since you could have different "scenes" with the same type of controllers.)
Ok, it seems is solved. I just have added a segue between scenes
and then I just need to add this one:
[self performSegueWithIdentifier:#"writePostViewSegue" sender:self];
and it works!. Anyway, I am not sure if it is the way to do it, so if someone knows better, please let me know.
Cheers

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