My data got delayed 1 time when I want to pass the data in my tableview and pass it to another viewcontroller
i'm using prepare for segue.
now, in order to get the right data i need go back to the table view and press the same row
override func prepare(for segue: UIStoryboardSegue, sender: Any?) {
if segue.identifier == "toRequestCorrection"{
let destinationVC = segue.destination as! RequestCorrectionViewController
if let indexPath = tableView.indexPathForSelectedRow{
destinationVC.Shift = self.correction["Shift"].stringValue
destinationVC.LogDate = self.correction["LogDate"].stringValue
destinationVC.logIn = self.correction["ActualLogIn"].stringValue
destinationVC.logOut = self.correction["ActualLogOut"].stringValue
destinationVC.breakEnd = self.correction["ActualBreakEnd"].stringValue
destinationVC.breakStart = self.correction["ActualBreakStart"].stringValue
destinationVC.overTimeIn = self.correction["ActualOverTimeIn"].stringValue
destinationVC.overTimeOut = self.correction["ActualOverTimeOut"].stringValue
destinationVC.transactionStatusID = self.correction["TransactionStatusID"].intValue
}
}
}
it's should pass the data on the row right after i pressed the row
Additionally, you do not have to use segue, you can instantiate your view controller inside didSelectRowAt method with following code without prepareForSegue.
EDIT: You didn't indicate it's an async task. So, I am using Alamofire with completion handler. I think it will be useful for you.
typealias yourCompletionHandler = (Data?, _ message: String?, _ errorStatusCode: Int?) -> Void
func yourAsyncTask(handler: #escaping yourCompletionHandler) {
let parameters: [String: Any] = ["unitId": 4124]
let url = ""
Alamofire.request(url, method: .get, parameters: parameters)
.responseObject { (response: DataResponse<BaseListResponseParser<YourModel>>) in
switch response.result {
case .success:
if let result = response.result.value {
handler(result.listItems, nil, nil)
}
case .failure(let error):
print(error)
}
}
}
yourAsyncTask { [weak self] (yourModel, error, _) in
DispatchQueue.main.async {
guard let destination = UIStoryboard(name: "Main", bundle: nil)
.instantiateViewController(withIdentifier: "ViewControllerId") as? RequestCorrectionViewController else { return }
destination.Shift = yourModel.shift
navigationController?.pushViewController(destination, animated: true)
}
}
Using that way you do not need to create segue or prepareForSegue method.
You should implement tableVew(_:willSelectRowAt:) method of UITableViewDelegate in your viewController and set your correction property to selected row's value.
class YourSourceViewController: UITableViewDelegate{
var correction: Correction!
func tableView(_ tabelView: UITableView, willSelecRowAt indexPath: IndexPath) -> IndexPath?{
correction = correctionList[indexPath.row]
return indexPath
}
func prepare(for segue: UIStoryBoardSegue, sender: Any?){
//passing data to RequestCorrectionViewController.
//And also you don't need to check if indexPath is nil.
//Because this block will called only any row of tableView is selected.
}
}
Also note that you could do same thing in tableView(_:didSelectRowAt:) method but this method works after performing segues and cause the problem you are encountered too.
Edit
If you think using willSelectRowAt: method is a misusing, you can set your segue's source your viewController (instead of template cell) and set identifier on Storyboard and call it programmatically. like #vadian's said
func tableView(_ tabelView: UITableView, didSelecRowAt indexPath: IndexPath){
correction = correctionList[indexPath.row]
performSegue(withIdentifier "mySegueIdentifier", sender: self)
}
Related
The prepare(for segue: ) function runs, but the data is not sent to my destination ViewController. I am getting following error when loading that VC's collection view which has to receive the data:
Unexpectedly found nil while unwrapping an Optional value
I have confirmed that the segue type is a selection segue, the segue identifier is correct, and that the views work as far as displaying dummy data.
First view controller (DrawerVC):
let realm = try! Realm()
var allDrawers: Results<Drawer>?
override func tableView(_ tableView: UITableView, didSelectRowAt indexPath: IndexPath) {
print("goToTool segue")
performSegue(withIdentifier: "goToTool", sender: self)
}
override func prepare(for segue: UIStoryboardSegue, sender: Any?) {
if segue.identifier == "goToTool" {
print("Prepare for segue from drawerVC ran") // this runs!
let destinationVC = segue.destination as! ToolVC
if let indexPath = tableView.indexPathForSelectedRow {
destinationVC.selectedDrawer = allDrawers?[indexPath.row]
print("Selected drawer set to index path") // doesn't run :(
}
} else if segue.identifier == "goToEditCategory" {
_ = segue.destination as! EditCategoryVC
}
}
Destination view controller (ToolVC):
let realm = try! Realm()
var allTools: Results<Tool>?
var selectedDrawer: Drawer? {
didSet{
// doesn't run since selectedDrawer was never set :(
print("The selected drawer changed from \(oldValue) to \(selectedDrawer?.title)")
loadTools()
}
}
func loadTools() {
allTools = selectedDrawer?.tools.sorted(byKeyPath: "title", ascending: false)
toolCollectionView.reloadData() // this is where I get the optional value error
}
You are making a very common mistake.
In the destination view controller you are accessing the table view in loadTools() which is not connected yet at the moment you assign the selected drawer. Therefore the table view is nil and causes the crash.
A solution is to remove the didSet observer
var selectedDrawer: Drawer?
and load the data in viewDidLoad
func viewDidLoad() {
super.viewDidLoad()
if let drawer = selectedDrawer {
allTools = drawer.tools.sorted(byKeyPath: "title", ascending: false)
toolCollectionView.reloadData()
}
}
And if the segue is connected from the cell to the destination view controller remove the didSelectRowAt method.
I have two ViewControllers in the first I created a tableView where I can insert just a text into a cell.
In the SecondViewController I also have a tableView with the same function, bu HOW can I make it that when I click a cell in the first tableView, I can get into a separate SecondTableView (Array).
So I'm this far, but I think the categorize function must be in the didSelectRowAt, when I click a Row.
FirstViewController:
todos: This is a String Array (I want this as the Category)
override func prepare(for segue: UIStoryboardSegue, sender: Any?) {
if segue.identifier == "hhh"{
//let destination = segue.destination as? UINavigationController
let vc = segue.destination as? SecondViewController
}
}
func tableView(_ tableView: UITableView, didSelectRowAt indexPath: IndexPath) {
let vc = storyboard?.instantiateViewController(withIdentifier: "SecondViewController") as? SecondViewController
//label name
vc?.name = todos[indexPath.row]
self.present(vc!, animated: true, completion: nil)
tableView.deselectRow(at: indexPath, animated: true)
self.performSegue(withIdentifier: "hhh", sender: indexPath)
let indexpath = todos[indexPath.row]
print("indexpath:\(indexpath)")
print("row: \(indexPath.row)")
}
}
In the SecondViewController I have a SecondArray=[String]() these are actually the Todos.
On both ViewControllers I can insert a cell with text but don't know how to pass the data back:=?
In the comments I suggested using a UISplitViewController, as this works well with any kind of master/detail type of app. (In fact, it's an Xcode project type.)
But in case you require using a UINavigationController, here's what I to to "toggle" between two views this way:
FirstViewController:
#IBAction func showFrameVC() {
updateMaskImage()
self.performSegue(withIdentifier: "ShowSecondView", sender: self)
}
override func prepare(for segue: UIStoryboardSegue, sender: Any?) {
if segue.identifier == "ShowSecondView" {
if let vc = segue.destination as? FrameViewController {
vc.someValue = someValue
vc.firstVC = self
}
}
}
Basically, pass the instance of the first view controller along with any data you need to pass.
SecondViewController:
var someValue:String!
weak var subjectVC:FirstViewController!
override func viewWillDisappear(_ animated: Bool) {
super.viewWillDisappear(animated)
if isMovingFromParentViewController {
firstVC.someValue = someValue
}
}
Here you let the navigation controller do it's thing, which is pop the second view controller off the stack after passing back the data it changed. Since you are maintaining a weak value of the first view controller, you free up that memory when the second controller is released.
In your code, you are presenting your SecondViewController in 2 ways in same function.
self.present(vc!, animated: true, completion: nil)
and
self.performSegue(withIdentifier: "hhh", sender: indexPath)
intention of both lines are same, But 2 way of implementation.
if my thinking is right you don't have to perform segue (second line of code mentioned above and also No prepare for segue method).
I have two UITableView connected through segue. I am performing segue to pass data from my firstTableView to secondTableView using tableViewCell swipe action method and saving the passed data using NSUserDefaults code works ok. But, Every time when I passed data it calls segue(I know it supposed to) and pushing to my secondTableView..I want to pass data without pushing my firstTableView to secondTableView when passing data and I have action button to access my secondController directly from mainViewController.
func tableView(_ tableView: UITableView, editActionsForRowAtIndexPath indexPath: IndexPath) -> [UITableViewRowAction]? {
let shareAction = UITableViewRowAction(style: UITableViewRowActionStyle.normal, title: "xxxxxxxxxx") { (UITableViewRowAction, NSIndexPath) -> Void in
self.performSegue(withIdentifier: "shareSegue", sender: indexPath)
// self.dismiss(animated: true, completion: nil)
}
return shareAction
}
override func prepare(for segue: UIStoryboardSegue, sender: Any?) {
if (segue.identifier == "shareSegue") {
// initialize new view controller and cast it as your view controller
let viewController = segue.destination as! ViewController
// your new view controller should have property that will store passed value
viewController.labelcell = (sendSelectedData as String as String)
}
//// I also tried the following method with no segue but the results pretty much same....
let storyboard = UIStoryboard(name: "Main", bundle: nil)
let secondVC = storyboard.instantiateViewControllerWithIdentifier("secondTableView")
self.presentViewController(secondVC, animated: true, completion: nil)
Thanks in advance!!!
I want to move from one view controller to another and send userId:
func collectionView(collectionView: UICollectionView, didSelectItemAtIndexPath indexPath: NSIndexPath) {
self.performSegueWithIdentifier("chosenPerson", sender: self)
}
override func prepareForSegue(segue: UIStoryboardSegue, sender: AnyObject?) {
if segue.identifier == "chosenPerson" {
let chosenPerson = segue.destinationViewController as? chosenPersonViewController
let indexPaths = self.collectionView!.indexPathsForSelectedItems()!
let indexPath = indexPaths[0] as NSIndexPath
chosenPerson!.userID = self.usersArray[indexPath.row].userId
}
by clicking I get: "fatal error: unexpectedly found nil while unwrapping an Optional value"
what I do wrong?
If you have given segue in StoryBoard DON'T Call this self.performSegueWithIdentifier("chosenPerson", sender: self) method in didSelectItem
If you have given segue in storyboard override func prepareForSegue - this method calls first after that didSelectItem calls
Please refer storyBoard once (below Image for Sample)
I think problem is in self.usersArray[indexPath.row].userId May this returns nil
Swift2:
self.performSegueWithIdentifier("chosenPerson", sender: self)
Swift3:
self.performSegue(withIdentifier: "chosenPerson", sender: self)
Swift2:
override func prepareForSegue(segue: UIStoryboardSegue, sender: AnyObject?) {
if segue.identifier == "chosenPerson" {
let chosenPerson = segue.destinationViewController as? chosenPersonViewController
let indexPaths = self.collectionView!.indexPathsForSelectedItems()!
let indexPath = indexPaths[0] as NSIndexPath
chosenPerson!.userID = self.usersArray[indexPath.row].userId //May it found nil please re - check array values
}
Swift3:
override func prepare(for segue: UIStoryboardSegue, sender: Any?) {
if segue.identifier == "chosenPerson" {
let chosenPerson = segue.destination as! chosenPersonViewController
if let indexPath = collectionView.indexPathForSelectedItem {
chosenPerson!.userID = self.usersArray[indexPath.row].userId //May it found nil please re - check array values
}
}
}
When performing the segue, pass the indexPath as the sender and try using this switch statement. If you see "unknown segue" printed out when you select a cell, the destination controller is not of type chosenPersonViewController.
func collectionView(collectionView: UICollectionView, didSelectItemAtIndexPath indexPath: NSIndexPath) {
performSegueWithIdentifier("chosenPerson", sender: indexPath)
}
override func prepareForSegue(segue: UIStoryboardSegue, sender: AnyObject?) {
switch (segue.destinationViewController, sender) {
case (let controller as chosenPersonViewController, let indexPath as NSIndexPath):
controller.userID = usersArray[indexPath.row].userId
default:
print("unknown segue")
break
}
}
One possible issue could be that in your storyboard you have not set the identifier for your segue to be "chosenPerson". To fix this first make sure you have a segue between your first and second view controllers, which can be created by control dragging one from one view controller to another.
Then make sure the segue has an identifier, specifically: "chosenPerson". To do this: click on the segue between the first two view controllers, then navigate to the attributes tab, and then set the identifier box to be "chosenPerson". Save the storyboard with your changes and now you should be able to call prepareForSegue with that identifier and not experience a fatal error.
I get an error trying to set indexPath: initializer for conditional binding must have optional type
override func prepareForSegue(segue: UIStoryboardSegue,
sender: AnyObject?) {
if segue.identifier == "toStation" {
let detailViewController = segue.destinationViewController
as! toStation
if let indexPath = tableView.indexPathForSelectedRow! {
detailViewController.selectedStation = stationNameArray[indexPath.row]
}
}
}
if let indexPath = tableView.indexPathForSelectedRow!
You are binding indexPathForSelectedRow to indexPath view an if let statement to unwrap the optional indexPathForSelectedRow. This is a good approach. But at the same time you are using the bang statement ! to unwrap the optional. Effectively you are unwrapping the optional twice. Either use ! or an if let statement.
You receive this error because tableView.indexPathForSelectedRow! is no longer an optional value (you've unwrapped it). To fix this error, try removing the force unwrap operator ! at the end of if let.
if let indexPath = tableView.indexPathForSelectedRow { ... }
According to your question subject, I think you are trying to pass Indexpath into prepareForSegue, in your case, you can use didSelectRowAtIndexPath to pass a sender:
func tableView(tableView: UITableView, didSelectRowAtIndexPath indexPath: NSIndexPath) {
self.performSegueWithIdentifier("toStation", sender: indexPath);
}
then in prepareForSegue :
override func prepareForSegue(segue: UIStoryboardSegue!, sender: AnyObject!) {
if (segue.identifier == "toStation") {
let detailViewController = segue.destinationViewController
as! toStation
let row = (sender as! NSIndexPath).row; //we know that sender is an NSIndexPath here.
detailViewController.selectedStation = stationNameArray[row]
}
}
Hope this solve your problem.