I have a delegate method where if I press a button in the tableview, it should segue to another view controller and pass along data but it doesn't seem to work.
func goToVC(uid: String) { //delegate method
performSegue(withIdentifier: "showVC", sender: self) //Do I need this
}
override func tableView(_ tableView: UITableView, didSelectRowAt indexPath: IndexPath) {
performSegue(withIdentifier: "showVC", sender: self)
self.tableView.deselectRow(at: indexPath, animated: true)
}
override func prepare(for segue: UIStoryboardSegue, sender: Any?) {
if segue.identifier == "showVC" {
if let indexPath = tableView.indexPathForSelectedRow {
let guestVC = segue.destination as! GuestViewController
guestVC.ref = userArray[indexPath.row].ref
}
}
class MainViewController: UIViewController {
// set the cell's delegate in the data source
// pass the object to the cell from the data source
func tableView(_ tableView: UITableView, cellForRowAt indexPath: IndexPath) -> UITableViewCell {
cell.mainViewControllerDelegate = self
cell.object = someArray[indexPath.row]
}
// this is the method that gets called by the cell through the delegate
func pushToViewController(object: YourDataObject) {
let destination = SomeViewController()
destination.object = object
navigationController?.pushViewController(destination, animated: true)
}
}
class TheTableViewCell: UITableViewCell {
// create a delegate and a data object
var mainViewControllerDelegate: MainViewController?
var object: YourDataObject?
// this is the method that gets called when the button in the cell is tapped
#objc func buttonAction() {
mainViewControllerDelegate?.pushToViewController(object: object)
}
}
I highly recommend that beginners do not use Interface Builder. The less you use it early, the quicker you will understand more. Interface Builder is fool's gold for beginners.
You dont need delegate method here. Delegate method can be used if you need to pass the value from the child view controller.
What you are doing is exactly right. Make sure you set the segue identifier in the story board correctly.
And one more thing dont set your table IBOutlet as default tableView try setting a name apt for that table like toDoTable, so it will easy to debug.
Related
I want send data between UITableViewCell and UIViewController
I have a list of address, in my cell I have a button (edit) and I want to send all the information about the address in the cell
#IBOutlet weak var address: UILabel!
#IBOutlet weak var rfc: UILabel!
override func awakeFromNib() {
super.awakeFromNib()
}
override func setSelected(_ selected: Bool, animated: Bool) {
super.setSelected(selected, animated: animated)
}
override func prepare(for segue: UIStoryboardSegue, sender: Any?) {
if segue.destination is ContainerVC{
let vc = segue.destination as? ContainerVC
vc.address = self.address.text
}
}
Method does not override any method from its superclass
Let's use segue inside your controller which contains the tableview which uses your UITableViewCell
override func prepare(for segue: UIStoryboardSegue, sender: Any?) {
if segue.identifier == segueIdentifier,
let destination = segue.destination as? ContainerVC,
let selectedIndex = tableView.indexPathForSelectedRow?.row
{
destination.address = self.addresses[selectedIndex].text
self.navigationController?.pushViewController(destination, animated: true) // For example
}
}
To pass data from cell Class to Controller Class use delegate methods on edit action.
Define call back delegate method in UITableViewCell class:
var callBack: ((NSDictionary) -> (Void))?
Use DS as per your need.
On Edit Action call delegate method and pass the data
#IBAction func editAction(_ sender: Any) {
callBack?(dictionary)
}
In cellForRowAt indexPath call delegate method with cell object
cell.callBack = { (currentData : NSDictionary)
in
// Perform Action on data
}
To Pass Data from Controller class to cell class you can simply define a method in cell class and can call in cellForRowAt indexPath.
Define SetData(dictionary) in cell class
In View Controller
func tableView(_ tableView: UITableView, cellForRowAt indexPath: IndexPath) -> UITableViewCell {
let cell = tableViewOutlet.dequeueReusableCell(withIdentifier: "CellName", for: indexPath) as! CellClassName
cell.SetData(dict)
return cell
}
You need to do this from your UIViewController in which the UITableViewCell is implemented:
Assuming you have an array to populate your UITableView, the code would be something like:
import UIKit
class FirstViewController: UIViewController {
#IBOutlet weak var tableView: UITableView!
var addresses = [String]()
override func prepare(for segue: UIStoryboardSegue, sender: Any?) {
if segue.identifier == "showAddressDetail" {
if let secondViewController = segue.destination as? SecondViewController {
secondViewController.address = sender as! String
}
}
}
}
extension FirstViewController: UITableViewDataSource, UITableViewDelegate {
func tableView(_ tableView: UITableView, numberOfRowsInSection section: Int) -> Int {
return self.addresses.count
}
func tableView(_ tableView: UITableView, cellForRowAt indexPath: IndexPath) -> UITableViewCell {
let cell: YourTableViewCell = tableView.dequeueReusableCell(withIdentifier: "YourTableViewCell", for: indexPath) as! YourTableViewCell
cell.address = self.addresses[indexPath.row]
cell.delegate = self
return cell
}
Since you have to call your function from an action triggered by a button on your UITableViewCell, you can implement a protocol on your cell:
import UIKit
protocol YourTableViewCellDelegate: class {
func selectedAddress(address: String)
}
class YourTableViewCellDelegate: UITableViewCell {
weak var delegate: YourTableViewCellDelegate?
var address: String
}
And in your button action, call your delegate method like this:
#IBAction func selectAddress() {
self.delegate?.selectedAddress(address: self.address)
}
This will trigger the delegate on your UIViewController. To handle the call, don't forget to assign your cell delegate to your view controller and implement your cell delegate in your controller:
extension FirstViewController: YourTableViewCellDelegate {
func selectedAddress(address: String) {
// Do stuff with the selected address
}
}
I've UITableView and I'm passing selected Item from one UIViewController to another. To achieve this I have array of Item objects.
var array = [Item]()
for performing segue I'm passing sender parameter of buttonPressed action as sender of performSegue method.
#IBAction func buttonPressed(_ sender: UIButton) {
performSegue(withIdentifier: "identifier", sender: sender)
}
This button is inside UITableViewCell and has tag equal to indexPath.row which I set in TableView cellForRowAt data source method:
func tableView(_ tableView: UITableView, cellForRowAt indexPath: IndexPath) -> UITableViewCell {
...
cell.myButton.tag = indexPath.row
...
}
Then in ViewController's prepare method I downcast sender as UIButton and then I assign selectedItem variable in destination ViewController as Item from array with button.tag as index.
override func prepare(for segue: UIStoryboardSegue, sender: Any?) {
if segue.identifier == "identifier" {
let button = sender as! UIButton
let destinationVC = segue.destination as! ViewController2
destinationVC.selectedItem = array[button.tag]
}
}
Q: This works just fine, I'm using this for a long time but I have got feeling that this isn't the right solution. Is there any better?
My preference is to use the delegate pattern here.
In this approach, the view controller makes itself the delegate of every tableview cell it creates. It passes the Item to the cell. When the button in the cell is tapped, the cell sends the Item back to the view controller. In this way the view controller knows which Item was selected and should be sent to the next view controller.
To implement, begin by declaring a variable in your tableview cell to hold the Item:
weak var item: Item?
In your view controller, pass the item to the cell:
func tableView(_ tableView: UITableView, cellForRowAt indexPath: IndexPath) -> UITableViewCell {
//...
cell.item = array[indexPath.row]
//...
}
Next, declare a delegate protocol:
protocol ItemSelectionDelegate {
func itemSelected(_ item: Item)
}
Add a variable of this type to your custom table view cell, like so:
weak var delegate: ItemSelectionDelegate?
Make the button in your tableview cell call the delegate when tapped, passing it the item:
#IBAction func buttonPressed(_ sender: UIButton) {
if let item = item {
delegate?.itemSelected(item)
}
}
Now, make your view controller conform to this protocol:
class MyViewController: UIViewController, ..., ItemSelectionDelegate {
func itemSelected(_ item: Item) {
//...
}
}
Make sure to set the view controller as the delegate of each cell:
func tableView(_ tableView: UITableView, cellForRowAt indexPath: IndexPath) -> UITableViewCell {
//...
cell.item = array[indexPath.row]
cell.delegate = self
//...
}
Call your segue, but pass the Item instead of a button:
class MyViewController: UIViewController, ..., ItemSelectionDelegate {
func itemSelected(_ item: Item) {
performSegue(withIdentifier: "identifier", sender: item)
}
}
Now pass this to your next view controller:
override func prepare(for segue: UIStoryboardSegue, sender: Any?) {
if segue.identifier == "identifier" {
let destinationVC = segue.destination as! ViewController2
destinationVC.selectedItem = sender as? Item
}
}
This is definitely more work to set up, so use only if it makes sense to you.
If I don't get wrong, you had to get selected index path row in prepareForSegue:
if segue.identifier == "identifier" {
guard let destinationVC = segue.destination as? ViewController2 else { return }
guard let selectedIndexPath = self.tableView.indexPathForSelectedRow else { return }
destinationVC.selectedItem = selectedIndexPath.row
}
i'm a beginner in swift, but I do have a decent background in HTML,CSS, and some Java. I made this account to literally just ask this question, so i'll get straight to the point.
I really enjoy swift, but i've literally spent a f*cking week writing this same code over and over again, reviewing countless tutorials, books, guides, etc. To no avail; and i'm not going to lie, i'm getting reaaaaally tired of seeing 10+ errors stack up in my compiler as I keep trying to figure this out.
I have a ViewController, and I have a TableViewController - the ViewController being my home screen. On said viewController, I have two buttons, one is for BuildingItems, the other is BuildingBlocks. Both of which are segues.
on my TableViewController, I have buildBlocks and buildItems, both of which have their arrays defined.
What i'm trying to do, is depending on the button the user chose, I want that to then be the data that's used to populate my tableview. I can populate the tableview specifically by using the normal cell.textLabel?.text = arrayNameHere[indexPath.row] but obviously that doesn't solve my problem.
I hope that you're able to help me out here. I apologize for the crappy grammar and formatting, i've literally spent 4-5 hours a day this passed week trying to get this to work, and i've ended up just getting angry and deleting my entire project three different times. I'll include the code below. Again, excuse the formatting. I dont know why I can't seem to figure out swift, I keep trying every variation of delegate to try and pass something over that will let it work, but nothing is working.
ViewController:
#IBAction func BuildItems (_sender: Any) {
}
#IBAction func BuildBlocks (_sender: Any) {
}
In TableViewController:
let buildItems = ["these are all my", "arrays for this"]
let buildBlocks = ["same thing here","just saving time"]
class TableViewController: UITableViewController {
var myIndex = 0
override func tableView(_ tableView: UITableView, numberOfRowsInSection: Int) -> Int {
return buildItems.count
}
override func tableView(_ tableView: UITableView, cellForRowAt indexPath: IndexPath) -> UITableViewCell {
let cell = tableView.dequeueReusableCell(withIdentifier: "cell" for: indexPath)
cell.textLabel?.text = buildItems[indexPath.row]
return cell
}
override func tableView(_ tableView: UITableView, didSelectRowAt indexPath: IndexPath) {
myIndex = indexPath.row
}
}
You only need 1 segue: from the ViewController to the TableViewController.
In your ViewController make a variable for which button is pressed:
var category = ""
Change the value when a button is pressed, then segue:
#IBAction func BuildItems (_sender: Any) {
category = "BuildItems"
self.performSegue(withIdentifier: "segue", sender: self)
}
#IBAction func BuildBlocks (_sender: Any) {
category = "BuildBlocks"
self.performSegue(withIdentifier: "segue", sender: self)
}
Then in prepare:
override func prepare(for segue: UIStoryboardSegue, sender: Any?) {
if segue.identifier == "segue" {
let vc = segue.destination as! TableViewController
// Assuming you created a variable called sentCategory in the TableViewController
vc.sentCategory = category
}
}
In your TableViewController create an empty array:
let data = [String]()
In viewDidLoad:
if sentCategory == "BuildItems" {
data = buildItems
} else {
data = buildBlocks
}
Populate your TableView with the data variable.
A couple comments:
Keep everything in your class scope, unless you have a good reason not to.
You don't need delegates in this scenario. Pass data with a prepare function as shown above.
Create bool var in your tableView controller maybe and helpArray
var dataArray:[String] = []
var isBuildItem:Bool = false
In your first controller implement prepareForSegue method like this:
override func prepare(for segue: UIStoryboardSegue, sender: Any?) {
if let vc = segue.destination as? TableViewController {
//set true or false it depends of which button you click
vc.isBuildItem = //true or false
}
}
Then in viewDidLoad in your TableViewController check bool variable
if(isBuildItem:Bool){
dataArray = buildItems
}
else{
dataArray = buildBlocks
}
In all your tableView delegate methods change buildItems array with dataArray
in your ViewController:
import UIKit
var segueName = ""
class ViewController: UIViewController {
override func viewDidLoad() {
super.viewDidLoad()
// Do any additional setup after loading the view, typically from a nib.
}
override func didReceiveMemoryWarning() {
super.didReceiveMemoryWarning()
// Dispose of any resources that can be recreated.
}
override func prepare(for segue: UIStoryboardSegue, sender: Any?)
{
segueName = segue.identifier!
print(segueName)
}
}
TableViewController:
import UIKit
class TableViewController: UITableViewController
{
let animals = ["Cat","Dog","Mouse"]
let colors = ["White","Blue","Red"]
var arrayResult = [""]
override func viewDidLoad()
{
super.viewDidLoad()
if segueName == "seguebuttonA"
{
arrayResult = animals
}
else if segueName == "seguebuttonB"
{
arrayResult = colors
}
}
override func didReceiveMemoryWarning()
{
super.didReceiveMemoryWarning()
// Dispose of any resources that can be recreated.
}
// MARK: - Table view data source
override func numberOfSections(in tableView: UITableView) -> Int
{
// #warning Incomplete implementation, return the number of sections
return 1
}
override func tableView(_ tableView: UITableView, numberOfRowsInSection section: Int) -> Int
{
// #warning Incomplete implementation, return the number of rows
return arrayResult.count
}
override func tableView(_ tableView: UITableView, cellForRowAt indexPath: IndexPath) -> UITableViewCell
{
let cell = tableView.dequeueReusableCell(withIdentifier: "cellTest", for: indexPath) as! TableViewCell
// Configure the cell...
cell.titleLabel.text = arrayResult[indexPath.row]
return cell
}
}
Add segue name:
The complete example is in the link below, I hope I have helped, if you have any questions let me know.
https://github.com/cwilliams26/viewSegueTabelview/tree/master
I'm trying to do maybe one of the simplest and more confusing things for me until now
I wanna develop my own App , and in order to do it I need to be able to passing some information depending of which row user click (it's Swift lenguage)
We have a RootViewController(table view) and a DetailViewController (with 1 label and 1 image)
(our view)
Here is the code:
#IBOutlet weak var tableView: UITableView!
var vehicleData : [String] = ["Ferrari 458" , "Lamborghini Murcielago" , "Bugatti Veyron", "Mercedes Benz Biome"]
override func viewDidLoad() {
super.viewDidLoad()
// Do any additional setup after loading the view, typically from a nib.
var nib = UINib(nibName: "TableViewCell", bundle: nil)
tableView.registerNib(nib, forCellReuseIdentifier: "cell")
}
func tableView(tableView: UITableView, numberOfRowsInSection section: Int) -> Int {
return vehicleData.count
}
func tableView(tableView: UITableView, cellForRowAtIndexPath indexPath: NSIndexPath) -> UITableViewCell {
let cell:TableViewCell = self.tableView.dequeueReusableCellWithIdentifier("cell") as TableViewCell
cell.lblCarName.text = vehicleData[indexPath.row]
cell.imgCar.image = UIImage(named: vehicleData[indexPath.row])
return cell
}
func tableView(tableView: UITableView, didSelectRowAtIndexPath indexPath: NSIndexPath) {
performSegueWithIdentifier("DetailView", sender: self)
}
override func prepareForSegue(segue: UIStoryboardSegue, sender: AnyObject?) {
if(segue.identifier == "DetailView") {
var vc = segue.destinationViewController as DetailViewController
}
}
func tableView(tableView: UITableView, heightForRowAtIndexPath indexPath: NSIndexPath) -> CGFloat {
return 100
}
Custom TableViewCell class (has a xib File with cell)
class TableViewCell: UITableViewCell {
#IBOutlet weak var lblCarName: UILabel!
#IBOutlet weak var imgCar: UIImageView!
override func awakeFromNib() {
super.awakeFromNib()
// Initialization code
}
override func setSelected(selected: Bool, animated: Bool) {
super.setSelected(selected, animated: animated)
// Configure the view for the selected state
}
class DetailViewController: UIViewController {
#IBOutlet weak var lblDetail: UILabel!
#IBOutlet weak var imgDetail: UIImageView!
override func viewDidLoad() {
super.viewDidLoad()
}
The question is:
if user click Ferrari 458 , the lblDetail in DetailViewController would show: Ferrari 458 is a super car which is able to reach 325 km/ h ...... (whatever we want)
and imgDetail would be able to show an image (whatever we want) of the car
If user click Bugatti Veyron now the lblDetail show us: Bugatti Veyron is a perfect and super sport machine. It's one of the fastest car in the world....
imgDetail show us an image of this car
Same thing with all cars depending which row we have clicked
I know the work is around prepareForSegue func in first View Controller but i was trying a lot of different ways to make it possible and anything runs ok
How we can do this???
Here is the example for you:
var valueToPass:String!
func tableView(tableView: UITableView!, didSelectRowAtIndexPath indexPath: NSIndexPath!) {
println("You selected cell #\(indexPath.row)!")
// Get Cell Label
let indexPath = tableView.indexPathForSelectedRow!
let currentCell = tableView.cellForRowAtIndexPath(indexPath)! as UITableViewCell
valueToPass = currentCell.textLabel.text
performSegueWithIdentifier("yourSegueIdentifer", sender: self)
}
override func prepareForSegue(segue: UIStoryboardSegue, sender: AnyObject?){
if (segue.identifier == "yourSegueIdentifer") {
// initialize new view controller and cast it as your view controller
var viewController = segue.destinationViewController as AnotherViewController
// your new view controller should have property that will store passed value
viewController.passedValue = valueToPass
}
}
But don't forget to create a passedValue variable into your DetailViewController.
This is just an example of passing data from one viewController to another and you can pass data with this example as you need.
And for more info refer this links.
Passing values between ViewControllers based on list selection in Swift
Use didSelectRowAtIndexPath or prepareForSegue method for UITableView?
Swift: Pass UITableViewCell label to new ViewController
https://teamtreehouse.com/forum/help-swift-segue-with-variables-is-not-working
May be this will help you.
Swift 3.0
var valueToPass:String!
func tableView(_ tableView: UITableView, didSelectRowAt indexPath: IndexPath) {
print("You selected cell #\(indexPath.row)!")
// Get Cell Label
let indexPath = tableView.indexPathForSelectedRow!
let currentCell = tableView.cellForRow(at: indexPath)! as UITableViewCell
valueToPass = currentCell.textLabel?.text
performSegue(withIdentifier: "yourSegueIdentifer", sender: self)
}
func prepareForSegue(segue: UIStoryboardSegue, sender: AnyObject?){
if (segue.identifier == "yourSegueIdentifer") {
// initialize new view controller and cast it as your view controller
var viewController = segue.destination as! AnotherViewController
// your new view controller should have property that will store passed value
viewController.passedValue = valueToPass
}
}
This may be another solution, without much code in didSelectRowAtIndexPath method.
Note that while it may look cleaner, and we do not need an extra variable valueToPass, it may not be a best practice, because the sender argument inside performSegue method is supposed to be the actual object that initiated the segue (or nil).
// MARK: UITableViewDelegate methods
func tableView(_ tableView: UITableView, didSelectRowAt indexPath: IndexPath) {
tableView.deselectRow(at: indexPath, animated: true)
performSegue(withIdentifier: "goToSecondVC", sender: indexPath)
}
// MARK: UIViewController methods
override func prepare(for segue: UIStoryboardSegue, sender: Any?) {
if segue.identifier == "goToSecondVC" {
if segue.destination.isKind(of: CarDetailsController.self) {
let secondVC = segue.destination as! CarDetailsController
let indexPath = sender as! IndexPath
secondVC.passedValue = carsArray[indexPath.row]
}
}
}
If you drag a segue from the prototype cell (in the Interface Builder) to your next View Controller and set its segue identifier to "Your Segue Identifier", you can also do it with this shortcut:
override func prepare(for segue: UIStoryboardSegue, sender: Any?) {
if segue.identifier == "Your Segue Identifier" {
let cell = sender as! YourCustomCell
let vc = segue.destination as! PushedViewController
vc.valueToPass = cell.textLabel?.text // or custom label
}
}
And you also don't need the performSegueWithIdentifier() in the didSelectRowAtIndexPath(), nor this Table View method.
In PushedViewController.swift (the next View Controller):
var valueToPass: String!
override func viewDidLoad() {
super.viewDidLoad()
yourLabel.text = valueToPass
}
It's important to set the label's value after it initialized from the Storyboard. That means, you can't set the label in the previous View Controller's prepareForSegue() directly, therefore needing to pass it with valueToPass.
Its simple, am adding one statement to above answer.
To get the selected car name in detail view label,
lblDetail.text = passedValue
you can add this code of line in viewDidLoad() func of your detailed view. passedValue contains the name of car which user selected(assign in prepareForSegue) then you can assign to your detailedView label.
Hope it helps!!
I am passing data from a table view controller to a detail view. I tried using indexPath.row directly in my prepareForSegue method, however it displays an error of
use of unresolved identifier 'indexPath'
So, after searching the web, I set up the variable indexOfSelectedPerson which is assigned the value of indexPath.row. The problem when I run the app in the simulator is that prepareForSegue is getting the initial value of indexOfSelectedPerson (0), then getting the value of the selected row only after I click it. So, when I hit the back button in the Simulator and select a different row, the detail view shows the info of the row I selected the previous time.
import UIKit
class MasterTableViewController: UITableViewController {
var people = []
var indexOfSelectedPerson = 0
override func viewDidLoad() {
super.viewDidLoad()
people = ["Bob", "Doug", "Jill"]
}
override func numberOfSectionsInTableView(tableView: UITableView?) -> Int {
return 1
}
override func tableView(tableView: UITableView?, numberOfRowsInSection section: Int) -> Int {
return people.count
}
override func tableView(tableView: UITableView!, cellForRowAtIndexPath indexPath: NSIndexPath!) -> UITableViewCell! {
let cell = tableView!.dequeueReusableCellWithIdentifier("personCell", forIndexPath: indexPath) as UITableViewCell
cell.text = "\(people[indexPath.row])"
return cell
}
override func tableView(tableView: UITableView!, didSelectRowAtIndexPath indexPath: NSIndexPath!)
{
indexOfSelectedPerson = indexPath.row
}
override func prepareForSegue(segue: UIStoryboardSegue!, sender: AnyObject!) {
if let mySegue = segue.identifier {
if mySegue == "personDetails" {
let detailsVC: DetailTableViewController = segue.destinationViewController as DetailTableViewController
detailsVC.selectedPersonName = "\(people[indexOfSelectedPerson])"
}
}
}
}
So, selecting Doug when the app first starts in the simulator displays the details for Bob because indexPathOfSelectedPerson is 0. Hitting the back button and then selecting Jill displays the details for Doug because indexPathOfSelectedPerson became 1 when I clicked on Doug the previous time. I'm guessing the problem stems from the order in which the methods are called.
The best way to do this kind of thing is not to use the delegate.
Updated Swift 4+
override func prepare(for segue: UIStoryboardSegue, sender: Any?) {
let selectedIndex = tableView.indexPath(for: sender as! UITableViewCell)
// Do your stuff with selectedIndex.row as the index
}
Original Answer
override func prepareForSegue(segue: UIStoryboardSegue!, sender: AnyObject!) {
let selectedIndex = self.tableView.indexPathForCell(sender as UITableViewCell)
// Do your stuff with selectedIndex.row as the index
}
Swift 3 update:
override func prepare(for segue: UIStoryboardSegue, sender: Any?) {
let selectedIndex = tableView.indexPath(for: sender as! UITableViewCell)!
// Do your actual preparing here...
}
//In didSelectRowAtIndexPath, you use this code:
func tableView(tvMain: UITableView, didSelectRowAtIndexPath indexPath: NSIndexPath) {
self.performSegueWithIdentifier("yourSegueName", sender: nil)
}
//And prepareForSegue to get IndexPath and send your value
override func prepareForSegue(segue: UIStoryboardSegue,
sender: AnyObject!){
let indexPath : NSIndexPath = self.yourTableView.indexPathForSelectedRow()!
//make sure that the segue is going to secondViewController
let detailsVC = segue.destinationViewController as DetailTableViewController
detailsVC.selectedPersonName = "\(people[indexPath.row])"
}