I need to create a modal "flow" within my app. It is made of two "scenes", these are both UITableViewController subclasses.
The user will be able to push and pop between these two table views.
At any point they will be able to press "Done" (in a nav bar) and dismiss the entire modal view to go back to where they were.
This whole modal flow needs to be accessible from several places in the app. I don't really want to create multiple modal segues to this.
My question is, creating this in a storyboard, would you create a whole new storyboard for this flow (I don't like this).
Would you just create multiple modal segues?
Should I create this flow in the same storyboard file but as a separate entity accessible by the identifier?
Or something else?
Sounds like it would be easier to use a single storyboard, but not create multiple segues everywhere. You can programmatically present the view controller pretty easily:
MyViewController *vc = [self.storyboard instantiateViewControllerWithIdentifier:#"MyViewController"];
// set any properties on vc here, if necessary to pass it any data
[self.window.rootViewController presentModalViewController:vc animated:YES];
You could place all this code in a helper method to reuse this code more easily, maybe a class method like this:
#interface MyViewController ...
+ (void)presentNewViewControllerModally;
...
#end
Tapping the done button:
[self.window.rootViewController dismissModalViewControllerAnimated:YES];
Note that if there's a good chance you'll never see this modal view controller, you could place that view controller in a separate xib file instead of in the storyboard, and I think that could make things more efficient (storyboard remains more lightweight). In this case, just replace the instantiteViewControllerWithIdentifier message above with:
[[MyViewController alloc] initWithNibName:#"SomeNib" bundle:nil];
...and the rest of the code is the same. I've used this technique for a "login" view controller that would only occasionally need to be presented.
Related
I am developing an application with iOS 9 based SDK , this is my first time I am working with Storyboards , I have 20 view controllers, each scene has Next / Previous buttons to go back and forward . I have a huge problem with going forward !. If I move from scene 1 to for example to scene 15 I received memory warning and then application crashes . I have searched and it seems there is method called unwind segue but it seems this is for going back ! it's something like dissMiss method .
I connect each scene with line in Interface Builder :
Here is segue's setting :
I would be grateful if you help me out .
EDITED :
I tried to present a view controller programmatically but result was the same ! .
UIStoryboard *mainStoryboard = [UIStoryboard storyboardWithName:#"Main" bundle:nil];
WhatIsDino *vc = (WhatIsDino*)[mainStoryboard instantiateViewControllerWithIdentifier:#"WID"];
[self presentViewController:vc animated:YES completion:nil];
Seems like it's a problem of wrong approach, and not the storyboard.
Let me guess, since before storyboard you used to change your app's rootViewController to the next/previous screen once you tap on the arrow button. So previous screen are released and deallocated from memory once you set a new rootViewController.
And now you're presenting every next view controller modally, which involved creating new UIWindow and loads all the hierarchy of you screen and keeps previous underneath the new one so it holds the memory and you're getting out of memory crash.
Well, you can do rootViewController approach with a storyboard too since it's just another way to manage your screens while development. Storyboard offers additional features like segues, static table view cells, general tint color and so on. [UIStoryboard -instantiateViewControllerWithIdentifier:] is the method you might find interesting.
But I'd rather recommend you to check out the UIPageViewController, it's like a container for the screens. Unfortunately, it cannot have the segues to your scenes (because of the special way segues work) so you have to use -instantiateViewControllerWithIdentifier: method anyway. You can treat inner view controllers of UIPageViewController as you do with rootViewController before.
You can also navigate without segue and Its easy way I think.
If you want to navigate from Class1 to Class 2 then follow these steps.
1) In Class 1, Import Class2.
2) In your button Action, Write this code.
Class2 *next = [self.storyboard instantiateViewControllerWithIdentifier:#"Class2 Identifier name"];
[self.navigationController pushViewController:next animated:YES];
Do not forget to give Identifier name in story board that is "Storyboard ID" in Attribute inspector of particular class.
No need to add Segue,Your storyboard would look clean.
The problem is that you are adding view controller after view controller with modal presentation. That causes each view controller to be added on top of the previous one, and all of them accumulate, using more and more memory.
Using a navigation controller and a push also piles the view controllers on top of each other.
You will have this problem if you use storyboards, nibs, or create the view controllers manually.
If you have a design where the user can move through a large series of view controllers then you probably want to dismiss the previous one before pushing/presenting a new one.
You can probably dismiss the previous view controller without animation and then present the new view controller each time you want to display a new one and avoid the memory issue. i'd have to experiment with it to get the effect I was after, but that's what I would suggest.
I am working with Parse, and one thing I have implemented in my app is their built in PFLogInViewController. This controller will be presented at two times in the application - when the app first starts and the user is not logged in, and when the user taps the "Log out" button of my application (logging out takes them back to the PFLogInViewController, as you are required to sign in to use the app). I would like to set this up using Storyboard, as that is how the rest of my app is laid out. How could I set up a central view controller (a PFLogInViewController) that is accessed at these two times? I have already Subclassed PFLogInViewController and set it up, I just need advice on how to place it in Storyboard and how to connect it to my views. To make this question help as many people as possible, the general theme of my question is how does one establish a central Login/ViewController that can be accessed at different points in the application using Storyboard. Attached is the basic idea of what I'm trying to accomplish. I haven't been able to successfully segue to the initial TabBarController, and I'm not sure how I should make the LoginController the initial ViewController if I can't segue. I am programming in Swift, if it matters.
There are a few ways to do this depending upon your application. One way is drop a UIViewController onto the storyboard, but don't wire it up to anything (no segue). Create a storyboard id for it such as "MyLoginVC". Do the necessary subclassing of UIViewController and attach the class to your VC. Then, when you want to display the VC simply do the following or wire this up to your logout button
id destinationVC = [self.storyboard instantiateViewControllerWithIdentifier:#"MyLoginVC"];
[self.navigationController pushViewController:destinationVC animated:YES];
In addition, if you want to show the login VC as the very first VC when you launch your app, then perhaps in your AppDelegate
// Load Root view controller
UIStoryboard *storyboard = [UIStoryboard storyboardWithName:#"Main" bundle:nil];
self.rootVC = [storyboard instantiateInitialViewController];
self.window.rootViewController = _rootVC;
[self.window makeKeyAndVisible];
// Load Login view controller
id initialVC = [storyboard instantiateViewControllerWithIdentifier:#"MyLoginVC"];
[initialVC setModalPresentationStyle:UIModalPresentationFullScreen];
[_rootVC presentModalViewController:initialVC animated:NO];
When you finish with your login VC (i.e. successful login) then within login VC
[self dismissViewControllerAnimated:NO completion:nil];
and alternatively instantiate your first VC with something similar to the following from within login VC. Note, since you loaded the root VC above first, it is already there with the login VC sitting over it. When you dismiss login VC, the underlying root VC should be ready to rock and roll. Otherwise you can do the following:
- (void)prepareForSegue:(UIStoryboardSegue *)segue sender:(id)sender
{
RootTabBarController *tbController = (RootTabBarController *)[self.storyboard instantiateViewControllerWithIdentifier:#"rootTabBarController"];
[self presentViewController:tbController animated:YES completion:NULL];
}
I think what you want is an unwind segue. Here are the instructions I follow for an unwind segue: https://github.com/bradley/iOSUnwindSegueProgramatically
If the link dies, here is what it said:
In your storyboard create two view controllers.
Subclass UIViewController twice, once for each of the view controllers in your storyboard.
Connect these view controllers to the view controllers in your storyboard.
Make a segue between the first view controller and the second by control+dragging from the first to the second.
Click on the segue you created and give it an identifier in the attributes inspector.
Make a button on the first view controller and link it to an IBAction in its UIViewController subclass.
When this button is pressed, the second storyboard should appear. To make this happen (we are doing it programatically) put the following into the implementation of the action you just created:
[self performSegueWithIdentifier:#"nameOfTheSegueBetweenOneAndTwo" sender:self];
Create a second method in the implemention of the first view controller with the following:
- (IBAction)returnToStepOne:(UIStoryboardSegue *)segue {
NSLog(#"And now we are back.");
}
This method will work to unwind any view controller back to this view controller. Notice that we implement the method in the view controller we wish to return to.
Go back to the storyboard. Focus in on the second view controller. If it is active, you should see a dark bar beneath it with 3 symbols on it. One of these is orange and when hovered over will show the name of the UIViewController subclass that this view controller represents. Control drag from this symbol woth the green symbol that means 'Exit'. You should see all available segue unwinds, which XCode automatically enumerates when you create segue unwind implementations inside UIViewController subclasses that you have shown on your stroryboard. Hence, you should see the segue 'returnToStepOne' as an option. Select it.
In your storyboard's document outline, find the section for the second view controller. You should see an item listed below it with a grey symbol that says something like "Unwind segue from ... to Exit." Click on this item.
Important and easily missed step follows!
On the right side of your storyboard, in the attributes inspector, you should see two fields. One for 'Identifier' and one for 'Action'. In most cases, the 'Action' field will have the text 'returnToStepOne:', which is what we want, but the 'Identifier' field will be blank. Fill this field with the text: 'returnToStepOne' (note that we leave out the colon).
Create a button on the second view controller and link it to an IBAction in its UIViewController subclass.
In the implementation for the method you just created, put the following code:
[self performSegueWithIdentifier:#"returnToStepOne" sender:self];
Run the application. You should now be able to unwind from the second view controller to the first.
One of the things I don't like about WYSIWYG/visual programming, is when you get to a point where you need to step outside of the box, you're left scratching your head. I'm at such a point right now along my iOS learning curve.
I have a custom UICollectionView thing. In two places (create and edit points), I need to present a list to the user to enable/disable (select/deselect) items from a list. So I go to the storyboard and whip up something like this:
In the past, following tutorials, I would control-drag a link from some control to the NavigationController show in the middle, I would tell it was a modal segue, tune a couple of methods, and get an arrow connecting the two for my efforts.
But in this case, I don't have obvious points to start that action from. I do have a + button. But it needs to do some other things first, and if all is well, then programmatically initiate the open, and somehow get notified of the state when it returns. Same for the individual cells, they might want to configure my table controller, and then open it, and be notified when it closes.
So I'm looking for a recipe of how one does this, what the key methods I should be looking for are. Apple's docs are great for reference, but I find figuring out how to do something from scratch difficult.
After creating a segue in your storyboard, you can initiate a segue any time programmatically by calling
[self performSegueWithIdentifier:#"segueID" sender:person];
Where "segueID" is a string you set for your segue in interface builder in the Identifier field in the identity inspector (right menu panel, 4th tab).
The segue does not need to be created from a control, you can just create one directly from one view controller to another. I usually do this on the right side menu by right-clicking on one view controller object and dragging to another one. This way, it acts as a segue that you can initiate programmatically any time you want.
As for getting notified when you come back to a view controller, (unless I'm misunderstanding your question) you can use either:
(void)viewWillAppear:(BOOL)animated
(void)viewDidAppear:(BOOL)animated
Create a UINavigationController programmatically with a desired view controller set as a root view controller. Here is an example of what you could put in a method invoked when user taps the plus button:
UIViewController *vc = [[UIStoryboard storyboardWithName:#"YourStoryboardName" bundle:nil] instantiateViewControllerWithIdentifier:#"YourViewControllerID"];
UINavigationController *nc = [[UINavigationController alloc] initWithRootViewController:vc];
[self presentViewController:nc
animated:YES completion:nil];
To get a state, or information about the selected items you can use Delegation and declare a protocol. Example:
#protocol YourSampleDelegate <NSObject>
- (void)didSelectItem:(NSObject *)item;
#end
Then, your view controller (the one with the plus sign) should implement this protocol:
#interface ViewController : UIViewController<YourSampleDelegate>
...
#end
#implementation ViewController
...
#pragma mark - YourSampleDelegate conformance
- (void)didSelectItem:(NSObject *)item;
{
// Do something with the item.
}
#end
You also have to create a delegate property in a view controller with collection view and set the view controller with a plus as a delegate. There are tons of examples on the Internet. I hope this shows you the right direction.
I have App with single storyboard, and two view in same story board. First one is controlled by ViewController and second one is controlled by View.(Two different class files, one inherits UIViewController and another UIView). App loads the first story board which is linked to UIViewController.
Now, I want to check some conditions in NSUserDefaults and skip the first view on app load if the condition is true. Skip first view can also be automatically load second view, this what I am trying to accomplish.
I have searched a lot and all of them were about the Navigation Controller, My views/controllers are not navigation controller, also I dnt want to use that because of the automatic navigation bar which I dont want.
Please help! Thanks.
remember to import the secondView,
and in storyboard you have to give the identifier "SecondView" to secondViewController
if ([[NSUserDefaults standardUserDefaults]boolForKey:#"Yes"]) {
SecondViewController *sv = (SecondViewController *)[self.storyboard
istantiateViewControllerWithIdentifier:#"SecondView"];
sv.modalTransitionStyle = UIModalTransitionStyleCrossDissolve;
[self presentViewController:sv animated:YES completion:Nil];
}
Okay, so far I've two view controllers in my storyboard. One with "login" elements and other as "User's home" sort of thing. I am intending to do the following : When user clicks on login, there's a bit of processing and then it should show to user's home screen..
When I do it via storyboard, i mean = control drag "login" button to user's home view it works fine. But I cant use that as I've to process the login data. It also shows some animation meanwhile. So, I've to do this shift programmatically. I wrote following code in the login button's IBAction ::
HomeViewController *homeView = [[HomeViewController alloc] init];
[self presentViewController:homeView animated:YES completion:NULL] ;
Now, this takes user to the intended view. However, the elements in the homeview (say a label, navigation bar are not being shown. And thats what my worry is.
(In theory, I can build entire view programatically but i think thats not the proper way of doing this, is it ? I want to make use of storyboard functionality in full i.e. design maximum UI in storyboard and use them from the backend how you want them to work.)
How do I do it ?
Cheers.
PS : I intend to add few more view controllers so at the moment i didn't think of navigation controller. not sure, if i should use it.
Using storyboards you should be using:
UIViewController *homeView = [self.storyboard instantiateViewControllerWithIdentifier:#"someID"];
[self presentViewController:homeView animated:YES completion:NULL] ;
Then set the ID to the view controller in storyboard like so:
Additionally, if you wish to there is absolutely nothing wrong with designing your UI entirely in code. Personally I prefer it. It gives you much more flexibility than interface builder.
In addition to NSPostWhenIdle's suggestion of instantiateViewControllerWithIdentifier, you can also define a segue between the two view controllers (not between the button and the second controller, but between the two view controllers):
Then give the segue a unique identifier, and then have your IBAction method do a performSegueWithIdentifier. This way your storyboard will continue to visually represent the various relationships between your view controllers.