I think this could be a simple question but I cannot seem to figure it out.
I have a screen which displays questions from an array. When the array has reached the end I want it to display another VC I have created. With all my other VC they are connected in the storyboard using segues between them. However, I only want this screen to display if I have reached the end of my array? Is what I am trying to doing making sense? Or does anyone know of any useful tutorials I could look at to figure it out for myself?
You can "manually" fire a seque with the performSegueWithIdentifier:sender: method using the segue identifier that you set on the segue in the storyboard. When you call that method the system sets up the right information and then executes prepareForSegue:sender: and then actually does the segue -- so the setup looks the same as an automatic segue trigger.
You can "manually" perform any segue with an identifier.
As to creating the segue to perform, you can create a segue from one View Controller to another in the storyboard (i.e. control-drag from the View Controller in the sidebar not from a button or a TableView cell or whatever). This sort of segue will have to be performed "manually".
Your call to do the "NextVCPlease" segue might look like:
if (lastQuestionDone) {
[self performSegueWithIdentifier:#"NextVCPlease" sender:whateverMakesSense]
}
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 2 UIView for my app, one main view, and one detailed view. From the main View, I open a detailed detailed view, where I have a table, with a segue. I want to return to the main view when clicking in one of the cells of this table. As I want to return some data, I set up a segue, but yet I was not able to run the code in the segue, and then return to the main view. It works when adding a button (exit), but not when using the code
I already checked this:
Using delegates to transfer data from one TableView to another
and lots of others, but I didn't found somebody who has the same problem.
Do you have any idea how to solve this?
Thanks a lot,
Alexander
In Storyboard, you can connect an unwind segue from the cell in your detail view to the unwind method you added in your main view controller.
Don't add any code to the detail's didSelectCellAtIndexPath: as it will not run before the segue.
Instead, set any properties you want to return in prepareForSegue.
The unwind segue will be called when the cell is selected, and the main view controller will be able to access those returned properties in its unwind method.
I'm writing an app that uses storyboarding and I want to update the labels in one view by clicking a button in a previous view.
_label.text = variable1;
is the line I would use to change the value of label, which is in the next view, when I click the button. Using this method I can easily change labels in the same view as the button but it does nothing when I go to the next view and see empty labels.
I've tried looking everywhere and found similar issues but couldn't find anything that worked for me so any solution would be very appreciated!
Unfortunately, it is not possible to connect IBOutlets between different scenes in storyboard.
It is difficult to suggest some precise solution because you have to provide more details about the setup which you have. Still, it is possible to outline some possible solutions:
Using prepareForSegue
If the view controller which you want to modify appears after the segue is performed you can customise its appearance in prepareForSegue function.
Using delegation
You can assign the view controller which wants to modify another view controller as its delegate. For example, if ViewController1 wants to modify ViewController2:
#interface ViewController1: UIViewController {}
#property (nonatomic,weak) ViewController2 *controllerThatIWantToModify;
with such setup you can call:
self.controllerThatIWantToModify.label.text = variable1;
You use storyboards, so there must be a segue from your first viewController (with the button) to your second (with labels in it).
If it is the case, you can set up the labels of the second view controller from the prepareForSegue method of your first view controller.
This method is called with a segue object which has a destinationViewController property which is your second view controller.
If you have several segue from this viewController, you should check if it is the right segue and then set it up.
To do that you need to set up outlets that gives you access to the labels from the viewController.
Then you can either write a setUpLabelsWith:(NSString)text1 ... method in your view controller, or directly access the outlets from the first view controller (supposing their are not private).
Yes this supposes your second view controller has a custom class.
I am new to Swift and iOS development.
I am trying to create a demo app which simply shows details of an item in a new scene when clicked.
I tried using Storyboard but I learned that One cannot create segues directly from cells in a storyboard because the CollectionView is populated dynamically through the data source.
So I tried using performSegueWithIdentifier:sender but clicking an item doesn't trigger anything. I have set the Identifier for the Segue in Storyboard. I can't figure out what's wrong (As I am pretty new and don't understand the complete flow yet).
My first class is myFirstViewController.swift and second is mySecondViewController.swift
Please help (Where should I put the prepareForSegue, performSegue function?)
I am using xCode 6 on OS X Yosemite.
Your myFirstViewController class must implement the UICollectionViewDelegate protocol.
In InterfaceBuilder create a segue to your second viewController by ctrl-dragging from the viewController1 icon to the second viewController. Give that segue an identifier name in the property inspector.
In myFirstViewController.swift, implement the collectionView(_:didSelectItemAtIndexPath:), there you can call performSegueWithIdentifier with your segue's identifier name.
You can segue directly from a cell in storyboard. Simply right-click and drag from the cell in the storyboard to the detail view controller that you want to activate.
If you really don't want to do it that way. Then another option would be to right-click and drag from your main view controller to the detail view controller to create a generic segue. Then name the segue. After that, you can call perform segue in your collectionView(collectionView, didSelectItemAtIndexPath) method. (Make sure you connect your view controller to your collection view as a delegate for this method to get called.)
Either way, you need to write a prepareForSegue(segue, sender) method in your main view controller to pass the selected item to the detail view controller.
Good luck on your new learning adventure!
I need to create two Segue's from the same button, and then I want to programatically choice which one to use based on device orientation. The problem I'm having is that you can only seem to create one segue from a button to another view so when I add the second one it just changes the first.
How do you add a segue that either isn't linked to a button etc so I can do programatically or how are you supposed to do this. I want to have two views that get dynamically picked based on orientation rather than moving the objects based via code when rotated as there is alot of objects and custom stuff that would make it much simplier just to have two views.
You'd have to trigger the segue manually. Hook up the button to a method, then make two segues, one from each view controller to the other in your storyboard, then give it an identifier in IB, then in your method you can call "performSegueWithIdentifier:".
Additional Info
To make a manual segue, control-click from the view controller object in IB to another view controller and the box will pop up as "Manual Segue". Just make sure it has an identifier.
I would think you could have the button trigger an IBAction wherein you could make a choice based on orientation and then trigger the appropriate segue programmatically.