I have the following UI elements:
A table view cell with an associated segue
A save button that shows an alert if data is missing
A table view cell's segue does not run until the user lets go of the button. So they can do the following:
Tap and hold the cell
While holding cell, tap the save button
Let go of cell
This brings up the alert and performs the segue behind it! Seems like iOS should not run the segue, but at least on iOS 10 it allows this behavior. How can I fix this issue?
Add the following code to your view controller:
override func shouldPerformSegue(withIdentifier identifier: String, sender: Any?) -> Bool {
return presentedViewController == nil
}
This will prevent any segue when a modal view controller is presented.
Related
my Storyboard looks like:
User can go directly from the 1st screen to the 4th. The fourth screen contains tableView, with XIB cell design. I want user to be able to tap on a cell and get to the 3rd screen and send some data with that. I know this should be done in didSelectRowAt. But is it even possible?
Yes it is possible.
Create a segue. In your storyboard, ctrl-drag from the first button on top of your 4th screen to anywhere on your second screen. You should see a new segue created in your storyboard.
Give the segue an id. Click on the newly created segue, in the right panel, set the indentifier attribute under the Indentity Inspector tab.
Perform the segue. In your didSelectRowAt, add the following line:
self.performSegue(withIdentifier: "THE_ID_YOU_ASSIGNED_IN_STEP_2")
Send data to the destination segue. In your screen 4 view controller, add the following function:
override func prepare(for segue: UIStoryboardSegue, sender: Any?) {
if segue.identifier == "THE_ID_YOU_ASSIGNED_IN_STEP_2" {
if let destinationVC = segue.destination as? YOUR_SCREEN_3_VC {
// Send data to your VC, such as assigning values
}
}
}
I have this two controller liked by segue:
My problem is that:
when I tap on selected table view'cell in general I have to follow the segue and so go to other controller , but if a specific condition is true I have to show ad alert view and so I don't follow the segue and so don't go to those controller.
In this way when I tap on selected cell I go always on the other controller.
How do I solve this problem?
if you override this function segue wont continue if you return false, this gives you the oportunity to show a warning under certain conditions, after that you can performSegueWithIdentifier("segueidentifier", sender: self), and your good to go.
override func shouldPerformSegueWithIdentifier(identifier: String!, sender: AnyObject?) -> Bool {
if identifier == "segueidentifier" {
//show warning and perform segue with this identifier on the accept button listener.
return false
}
}
return true
}
You can add a segue from one controller to another without specifying exact view which triggers the segue. Then just check your condition in didSelectRow method and call performSegue method if you need to show new view controller:
if condition {
performSegue(withIdentifier: "MySegueIdentifier", sender: nil)
}
else {
//show ad here
}
To add a segue between controllers just drag with right mouse button from one controller to another and pick "Show".
Then select segue and add a string identifier for it:
Make sure you use the same string in the code when you call performSegue method.
I have simple app. My tableViews contains some words; I post data in post screen and I want to get back to the first tableView screen. I have use a segue for this. The problem is that each time after posting, clicking the post button opens a new tableView over the post screen. I want to return to the original.
Table View Screen -> Post Screen -> New Table View Screen
But I want
Table Vievscreen <-> Post Screen
I had the same issue.It is resolved now. Please let me know if this helps.
I already have a segue linked from table view cell to another view with name DynamicSuperView
func tableView(_tableView: UITableView, didSelectRowAt indexPath: IndexPath)
{
//Remove the below line from this function as it will perform segue.
//performSegue(withIdentifier: "DynamicSegue", sender: self)
}
override func prepare(for segue: UIStoryboardSegue, sender: AnyObject?) {
// This will actually perform your segue
var DestViewController = segue.destination as! DynamicSuperView
let selectedRow = tableView.indexPathForSelectedRow?.row
DestViewController.labelText = names[selectedRow!]
}
Hope this helps to somebody.
We need a LOT more information to what is provided. However this may get you started in the right way.
If you are using a navigation controller, put this in your posting view code:
navigationController!.popViewControllerAnimated(true)
If you are NOT using navigationController but instead showing the view modally, then use the following in your posting view code:
dismissViewControllerAnimated(true, completion: nil)
Most segues create a new instance of a view controller and display it on top of existing view controllers.
If you are adding a view controller to a navigation stack with a push, you want to do a pop as described in JAL's comment.
If your segue is modal, you want to do a dismissViewController:animated:
You could also set up an unwind segue, although that might be overkill for this simple case.
I'm getting the same issue here, but I realize that I just did wrong on control+click, I dragged from cell, the correct must be from tableview
I hope this help some one
I have a TableViewController and I would like to trigger a segue within its navigation bar. I created the segue in the storyboard to my new ViewController. However if I click the bar button item, the view does not appear.
Instead the bar button item becomes inactive (greyed out) and the app freezes. There is no error message and the app does also not crash. The prepareForSegue method in my TableViewController also gets called
override func prepareForSegue(segue: UIStoryboardSegue, sender: AnyObject?) {
print("prepare for segue called")
print("destination view controller = \(segue.destinationViewController.description)")
}
I did the following things:
created a custom view Controller class for the second screen (in my storyboard and as a .swift file). I assigned the respective ViewController in the storyboard to my custom view controller in the Identity inspector
created an IBAction for a click event on the button and triggered
the segue programatically. The result remains the same.
prepareForSegue is called. The destionationViewController is correct
but does not show up. I removed this IBAction afterwards.
My destination view controller looks like this
class EnterUserDataViewController : UIViewController {
override func viewDidLoad() {
super.viewDidLoad()
print("EnterUserDataViewController viewDidLoad called")
}
}
viewDidLoad never gets called even though the right segue has been triggered.
Can someone please give me a hint on why this happens?
You wouldn't happen to have a rogue breakpoint set somewhere would you?
If I put a breakpoint somewhere in the view loading cycle it recreates the exact symptoms you are describing.
I have a navigation controller, with a table view. When I press a cell, the detail view controller opens.
In my root view controller I have :
override func prepareForSegue(segue: UIStoryboardSegue, sender: AnyObject?) {
if segue.identifier == "detailview" {
var destination:DetailViewController = segue.destinationViewController as DetailViewController
destination.delegate=self
}
}
In my detail view controller I have a back button :
#IBAction func back() {
self.navigationController?.popViewControllerAnimated(true)
}
The issue is, after 2 go to and return, my app crashes when I go back on the root view controller pressing back button. The console doesn't give me errors. It just crashes.
I think I have forgotten to unwind the segue.
So in my detail view controller I added :
#IBAction func unwindToViewController(segue: UIStoryboardSegue) {
println("unwind function")
}
I connect this function to my back button with "exit" in my storyboard.
When I run my app, If I press on the back button, the console doesn't display my print "unwind function", so unwindToViewController isn't called. Why ?
And my app still crashes...
Your unwindToViewController method should be placed in your root viewController, then ctrl-drag from the button in the detailViewController to the Exit icon in InterfaceBuilder. Choose that method in the popup menu.
Another approach would be to declare a protocol with a function in the rootViewController that is called from the detailViewController. You already set the rootViewController as the delegate of the detailViewController. Within that function you call dismissViewController.
Swift answer...
I had a similar problem.
The func: "segueForUnwindingToViewController(toViewController: UIViewController, fromViewController: UIViewController, identifier: String?) -> UIStoryboardSegue" was never called.
Solution:
since I didn't have a "UINavigationController", because I simply embeded the app in a Navigation Controller, I created a UINavigationController subclass for the Navigation Controller and added the function named above on it. Now the app calls "segueForUnwindingToViewController"