Why the property does not pass to another view Controller? - swift

extension ReservationViewController: UITableViewDelegate {
func tableView(_ tableView: UITableView, didSelectRowAt indexPath: IndexPath) {
if let vc = storyboard?.instantiateViewController(withIdentifier: "restaurantDetail") as? RestaurantViewController {
vc.restaurantNametxt = searchRestaurant[indexPath.row].restaurantName
print(searchRestaurant[indexPath.row].restaurantName)
}
print(indexPath.row)
print(searchRestaurant[indexPath.row].restaurantID ?? "")
restaurantsTableView.deselectRow(at: indexPath, animated: true)
performSegue(withIdentifier: "restaurantDetail", sender: self)
}
}
class RestaurantViewController: UIViewController {
#IBOutlet weak var restaurantName: UILabel!
#IBOutlet weak var reserverButton: UIButton!
var restaurantNametxt: String = ""
override func viewDidLoad() {
super.viewDidLoad()
restaurantName.text = restaurantNametxt
print(restaurantNametxt)
}
#IBAction func reserverButtonPressed(_ sender: UIButton) {
performSegue(withIdentifier: "FinalStep", sender: self)
self.navigationItem.hidesBackButton = true
}
}
When the user performs didSelectRow at I want to pass searchRestaurant[indexPath.row].restaurantName to another vc which is RestaurantViewController but on UILabel is still "".
vc.restaurantNametxt contains the real restaurantName because it is printing the value.

Your approach fails because you do not use the vc you instantiated. With performSegue you create a new ViewController that gets presented. And its property is empty as you already discovered.
Try:
self.presentViewController(vc, animated: true, completion: nil)
and remove:
performSegue(withIdentifier: "restaurantDetail", sender: self)

Related

Passing access from tableViewController to another view controller

I have spent a fair bit of time on this and still can't seem to figure out what I'm doing wrong.
I would like to run the reloadData() function in my own function on another view controller than the tableViewController but I get the error Type 'HomeViewController' has no member 'reloadData'.
HomeViewController:
import UIKit
import CoreData
class HomeViewController: UIViewController, UITableViewDelegate, UITableViewDataSource {
var index = ""
var item : [ListItem] = [] //listName
var listName = [""]
override func viewDidLoad() {
super.viewDidLoad()
self.homeListsTableView.delegate = self
self.homeListsTableView.dataSource = self
homeListsTableView.reloadData()
//List Names
//List Items - Within a list Name
let listItem1 = ListItem()
listItem1.name = "" //Update so names are updated via append the ListItem Array
listItem1.location = ""
item.append(listItem1)
let listItem2 = ListItem()
listItem2.name = ""
listItem2.location = ""
item.append(listItem2)
}
#IBOutlet weak var homeListsTableView: UITableView!
#IBAction func templatesButton(_ sender: Any) {
tabBarController?.selectedIndex = 2
}
override func viewWillAppear(_ animated: Bool) {
if let context = (UIApplication.shared.delegate as? AppDelegate)?.persistentContainer.viewContext {
if let coreDataListItems = try? context.fetch(ListName.fetchRequest()) as? [ListName] {
print(coreDataListItems)
}
}
}
func tableView(_ tableView: UITableView, numberOfRowsInSection section: Int) -> Int {
return listName.count
}
func tableView(_ tableView: UITableView, cellForRowAt indexPath: IndexPath) -> UITableViewCell {
let cell = tableView.dequeueReusableCell(withIdentifier: "cell", for: indexPath)
cell.textLabel?.text = listName[indexPath.row]
return cell
}
func tableView(_ tableView: UITableView, didSelectRowAt indexPath: IndexPath) {
// performSegue(withIdentifier: "goToItems", sender: self)
}
override func prepare(for segue: UIStoryboardSegue, sender: Any?) {
let vc = segue.destination as! ListNameViewController
vc.homeListsTableViewVC = homeListsTableView
}
}
ListName View Controller:
import UIKit
import CoreData
class ListNameViewController: UIViewController, UITableViewDelegate {
// var listName = [""]
let context = (UIApplication.shared.delegate as? AppDelegate)?.persistentContainer.viewContext
var homeListsTableViewVC = HomeViewController.self
override func viewDidLoad() {
super.viewDidLoad()
}
#IBOutlet weak var listNameValue: UITextField!
#IBOutlet weak var locationOption: UITextField!
#IBOutlet weak var createButtonChange: UIButton!
#IBAction func createButton(_ sender: Any) {
let newList = ListName(context: context!)
newList.listName = listNameValue.text
// let location = locationOption.text!
//tabBarController?.selectedIndex = 0
//performSegue(withIdentifier: "home", sender: nil)
}
func saveList() {
do {
try context!.save()
} catch {
print("Error saving context \(error)")
}
homeListsTableViewVC.reloadData()
}
}
I'm trying to use the prepare for segue function to pass the homeListsTableView data to then use the reloadData() function. Could someone tell me what I'm doing wrong?
Thanks!
You can use delegate or closure to update your tableview.. here is pointers of how you can use closure in your classes to update view
class ListNameViewController: UIViewController, UITableViewDelegate {
var callback: (()->())?
//....
func saveList() {
do {
try context!.save()
} catch {
print("Error saving context \(error)")
}
callback?()
}
}
And while creating ListNameViewController
class HomeViewController: UIViewController, UITableViewDelegate, UITableViewDataSource {
override func prepare(for segue: UIStoryboardSegue, sender: Any?) {
let vc = segue.destination as! ListNameViewController
vc.callback = { [weak self] in
self?.homeListsTableView.reloadData()
}
}
}

PerformSegue from long press on a a custom UiTableViewCell

maybe the question has been asked several times, but can't find it.
I'm a newbie.
I have a UITableView with a custom UITableViewCell.
in the cell there are 3 different labels.
I added the gesture recognizer on the custom cell, so that if long press is done on a label :
- label 1 should show another UiViewController
- label 2 should do a call
- label 3 should create a mail
for labels 2 and 3 i had no problem
but how to perform the segue to open the view controller ?
This is the storyboard
This is the custom tableviewcell
import UIKit
import MessageUI
class OfficeCell: UITableViewCell, MFMailComposeViewControllerDelegate {
#IBOutlet weak var lbOffice: UILabel!
#IBOutlet weak var lbAddress: UILabel!
#IBOutlet weak var lbPhone: UILabel!
#IBOutlet weak var lbMail: UILabel!
override func awakeFromNib() {
super.awakeFromNib()
// Initialization code
}
override func setSelected(_ selected: Bool, animated: Bool) {
super.setSelected(selected, animated: animated)
self.setupLabelTap()
// Configure the view for the selected state
}
func setupLabelTap() {
let lbAddressTap = UILongPressGestureRecognizer(target: self, action: #selector(self.longPressReconizer(_:)))
self.lbAddress.isUserInteractionEnabled = true
self.lbAddress.addGestureRecognizer(lbAddressTap)
let lbAddressTap2 = UILongPressGestureRecognizer(target: self, action: #selector(self.longPressReconizer(_:)))
self.lbMail.isUserInteractionEnabled = true
self.lbMail.addGestureRecognizer(lbAddressTap2)
let lbAddressTap3 = UILongPressGestureRecognizer(target: self, action: #selector(self.longPressReconizer(_:)))
self.lbPhone.isUserInteractionEnabled = true
self.lbPhone.addGestureRecognizer(lbAddressTap3)
}
#objc func longPressReconizer(_ sender: UITapGestureRecognizer) {
print("labelTapped")
let etichetta :UILabel = sender.view as! UILabel
print (etichetta.text!)
switch etichetta.tag {
case 0:
self.performSegue(withIdentifier: "moveToMaps", sender: self)
case 1:
let telNumber = etichetta.text!.replacingOccurrences(of: " ", with: "")
if let phoneCallURL = URL(string: "telprompt://\(telNumber)") {
let application:UIApplication = UIApplication.shared
if (application.canOpenURL(phoneCallURL)) {
application.open(phoneCallURL, options: [:], completionHandler: nil)
}
}
case 2:
if MFMailComposeViewController.canSendMail() {
let mail = MFMailComposeViewController()
mail.mailComposeDelegate = self
mail.setToRecipients([etichetta.text!])
mail.setSubject("Informazioni")
self.window?.rootViewController?.present(mail, animated: true)
} else {
// show failure alert
}
default:
print("default")
}
}
func mailComposeController(_ controller:MFMailComposeViewController, didFinishWith result: MFMailComposeResult, error: Error?) {
controller.dismiss(animated: true)
}
}
but Xcode give me this error
Value of type 'OfficeCell' has no member 'performSegue'
on
self.performSegue(withIdentifier: "moveToMaps", sender: self)
how to achieve what i need ?
Thanks in advance
Fabrizio
you need to implement delegate and perform segue from main class because cell class can't perform segue ... in storyBoard attach "moveToMaps" segue from main controller
protocol CellDelegate {
func didTapAddressButton()
}
class OfficeCell: UITableViewCell, MFMailComposeViewControllerDelegate {
var delegate: CellDelegate?
}
In your main View controller class
override func tableView(_ tableView: UITableView, cellForRowAt indexPath: IndexPath) -> UITableViewCell {
let cell = tableView.dequeueReusableCell(withIdentifier: "OfficeCell", for: indexPath) as! OfficeCell
cell.delegate = self
return cell
}
extension MainController: CellDelegate {
func didTapAddressButton(){
self.performSegue(withIdentifier: "moveToMaps", sender: self)
}
}

TextFields don't get updated with values in unwind function Swift

I have textfields that should get a value displayed once returning from a TableViewController where user selects a cell. I get that value in unwindfunction, but textfieldsdon't get updated. When printing the value it prints correctly on unwinding, so unwindshould be set correctly, but it just don't get displayed in it's textfield. I also tried prepare(for unwind:in TableViewControllerbut with same results. Can you see what I'm doing wrong?
As always many thanks.
unwind function:
#IBAction func unwindToDetailsVc(segue: UIStoryboardSegue) {
//Insert function to be run upon dismiss of VC2
print("unwindSegue triggered")
if let vc = segue.source as? CityTableViewController {
print("segue source is city vc : \(String(describing: vc.city!))")
self.cityTextField.text = vc.city
}
if let vc = segue.source as? RegionTableViewController {
print("segue source is region vc : \(String(describing: vc.region!))")
self.regionTextField.text = vc.region
}
if let vc = segue.source as? CountryTableViewController {
print("segue source is country vc : \(String(describing: vc.country!))")
self.countryTextField.text = vc.country
}
}
didSelect in TableView:
func tableView(_ tableView: UITableView, didSelectRowAt indexPath: IndexPath) {
let cell = tableView.cellForRow(at: indexPath) as! CityTableViewCell
self.city = cell.cityLabel.text ?? ""
performSegue(withIdentifier: "unwindSegue", sender: self)
// self.dismiss(animated: true, completion: nil)
}
prepare for unwind:
override func prepare(for unwind: UIStoryboardSegue, sender: Any?) {
if unwind.identifier == "unwindSegue" {
if let detailsVc = unwind.destination as? ShopDetailsTableViewController {
detailsVc.cityTextField.text! = city
}
}
}
textfield delegate function:
func textFieldDidBeginEditing(_ textField: UITextField) {
print("Editing textfield")
if textField.accessibilityIdentifier == "city" {
print("Editing city textfield")
performSegue(withIdentifier: "citySegue", sender: self)
} else if textField.accessibilityIdentifier == "region" {
print("Editing regio textfield")
performSegue(withIdentifier: "regionSegue", sender: self)
} else if textField.accessibilityIdentifier == "country" {
print("Editing country textfield")
performSegue(withIdentifier: "countrySegue", sender: self)
}
}
You can simply use a closure to solve this kind of problem statement,
class ViewController: UIViewController {
#IBOutlet weak var textField: UITextField!
#IBAction func openTableVC(_ sender: UIButton) {
if let controller = UIStoryboard.init(name: "Main", bundle: nil).instantiateViewController(withIdentifier: "TableViewController") as? TableViewController {
controller.handler = {[weak self](city) in
DispatchQueue.main.async {
self?.textField.text = city
}
}
self.navigationController?.pushViewController(controller, animated: true)
}
}
}
class TableViewController: UITableViewController {
var handler: ((String)->())?
override func tableView(_ tableView: UITableView, didSelectRowAt indexPath: IndexPath) {
let city = "Delhi"
self.handler?(city)
self.navigationController?.popViewController(animated: true)
}
}
The above code is generic and will work in every case from where you want to open TableViewController.
I finally found out what I was doing wrong, I was calling the functions loading from CoreDatauser details and displaying them in viewWillAppear. Once I moved them in saveButtonafter the saving to CoreDatafunction call, it all works as expected. Textfield get updated with select values from tableviews.
Many thank to #PGDev for sharing a more convenient way of coding this, without all the if elsestatements and unwinds. Great example of higher level coding.

Blank labels after data passing in Swift 4?

I am currently trying to pass data from my table view controller to a second view controller but my labels and image are appearing as blank in the second view controller.
This is my main event view controller:
class EventsTableViewController: PFQueryTableViewController {
override func queryForTable() -> PFQuery<PFObject> {
let query = PFQuery(className: "Events")
//query.order(byAscending: "location")
query.order(byAscending: "date")
return query
}
override func viewDidLoad() {
super.viewDidLoad()
self.title = "Upcoming Events"
// Do any additional setup after loading the view.
}
override func didReceiveMemoryWarning() {
super.didReceiveMemoryWarning()
// Dispose of any resources that can be recreated.
func prepare(for segue: UIStoryboardSegue, sender: Any?) {
if segue.identifier == "MasterToDetail" {
let detailVC = segue.destination as! DetailViewController
detailVC.myEventCell = sender as? EventCell
}
}
}
override func tableView(_ tableView: UITableView, cellForRowAt indexPath: IndexPath, object: PFObject?) -> PFTableViewCell? {
let cell = tableView.dequeueReusableCell(withIdentifier: "cell", for: indexPath) as! EventCell
cell.dateLabel.text = object?.object(forKey: "date") as? String
cell.locationLabel.text = object?.object(forKey: "location") as? String
cell.nameLabel.text = object?.object(forKey: "name") as? String
let imageFile = object?.object(forKey: "image") as? PFFile
cell.eventImage.image = UIImage(named: "download")
cell.eventImage.file = imageFile
cell.eventImage.loadInBackground()
return cell
}
override func tableView(_ tableView: UITableView, didSelectRowAt indexPath: IndexPath) {
performSegue(withIdentifier: "MasterToDetail", sender: EventCell())
}
#IBAction func reloadTable(_ sender: Any) {
self.loadObjects()
}
#IBAction func onSignOutTapped(_ sender: Any) {
let firebaseAuth = Auth.auth()
do {
try firebaseAuth.signOut()
performSegue(withIdentifier: "signOutSegue", sender: nil)
} catch {
print (error)
}
}
}
and my second view controller:
class DetailViewController: UIViewController {
#IBOutlet weak var detailImageView: UIImageView!
#IBOutlet weak var detailNameLabel: UILabel!
#IBOutlet weak var detailDescriptionLabel: UILabel!
#IBOutlet weak var detailLocationLabel: UILabel!
var myEventCell: EventCell?
override func viewDidLoad() {
super.viewDidLoad()
setUI()
}
func setUI () {
detailNameLabel.text = myEventCell?.nameLabel.text
detailImageView.image = myEventCell?.eventImage.image
detailLocationLabel.text = myEventCell?.locationLabel.text
}
}
As you send an empty cell here
performSegue(withIdentifier: "MasterToDetail", sender: EventCell())
You need
let cell = tableView.cellForRow(at:indexPath)
performSegue(withIdentifier: "MasterToDetail", sender:cell)

unabe to Reload data in tableview via userdefault

I am a newbie and learning ios programming. I have made a custom table view cell. I am trying to append data in it via user defaults but its not storing the data, every time i go back the app refreshes making the table view blank screen.
// data sent from here
class ViewController: UIViewController {
#IBOutlet weak var textfield: UITextField!
override func viewDidLoad() {
super.viewDidLoad()
// Do any additional setup after loading the view, typically from a nib.
}
#IBAction func submit(_ sender: AnyObject) {
performSegue(withIdentifier: "move", sender: nil)
}
override func prepare(for segue: UIStoryboardSegue, sender: Any?) {
let destination = segue.destination as? secondviewcontroller
destination?.list.append(textfield.text!)
let defaults = UserDefaults.standard
defaults.set(destination?.list, forKey: "listarray")
UserDefaults.standard.synchronize()
}
}
// here i want to retreive
class secondviewcontroller: UIViewController {
#IBOutlet weak var tblView: UITableView!
var list = ["fahad","Ali","tahir"]
var abc = ""
override func viewDidLoad() {
super.viewDidLoad()
tblView.dataSource = self;
tblView.delegate = self;
let storedarray = UserDefaults.standard.object(forKey: "listarray")
print("hi\(storedarray)")
}
override func viewDidAppear(_ animated: Bool) {
tblView.register(TableViewCell.self, forCellReuseIdentifier: "TableViewCell")
tblView.reloadData()
}
#IBAction func backbtn(_ sender: AnyObject) {
dismiss(animated: true, completion: nil)
}
}
import UIKit
class secondviewcontroller: UIViewController {
#IBOutlet weak var tblView: UITableView!
var list = ["fahad","Ali","tahir"]
var abc = ""
override func viewDidLoad() {
super.viewDidLoad()
tblView.dataSource = self;
tblView.delegate = self;
}
override func viewDidAppear(_ animated: Bool) {
tblView.register(TableViewCell.self, forCellReuseIdentifier: "TableViewCell")
let storedarray = UserDefaults.standard.object(forKey: "listarray")
print("hi\(storedarray)")
tblView.reloadData()
}
#IBAction func backbtn(_ sender: AnyObject) {
dismiss(animated: true, completion: nil)
}
}
extension secondviewcontroller : UITableViewDataSource , UITableViewDelegate{
func numberOfSections(in tableView: UITableView) -> Int {
return 1;
}
func tableView(_ tableView: UITableView, numberOfRowsInSection section: Int) -> Int {
print (list)
return list.count;
}
func tableView(_ tableView: UITableView, cellForRowAt indexPath: IndexPath) -> UITableViewCell {
var cell = tableView.dequeueReusableCell(withIdentifier: "TableViewCell", for: indexPath) as! TableViewCell;
cell.textlabel.text = list[indexPath.row];
return cell;
}
}
// my custom table view
import UIKit
class TableViewCell: UITableViewCell {
#IBOutlet weak var textlabel: UILabel!
override func awakeFromNib() {
super.awakeFromNib()
}
}
My UI storyboardgetting this error
you must subclass the UITableViewDelegate and UITableViewDataSource methods and implement the required methods for it to display the data in your custom view.
refer to this: http://clean-swift.com/refactoring-table-view-data-source-and-delegate-methods/
try adding the code for stored array into the viewwillappear method..
These lines recreates the same list with an new element without considering the saved items:
destination?.list.append(textfield.text!)
let defaults = UserDefaults.standard
defaults.set(destination?.list, forKey: "listarray")
UserDefaults.standard.synchronize()
You should instead:
let newEntry = textfield.text!
let defaults = UserDefaults.standard
if destination?.list.count == 3 { //3 because you hardcoded 3 items in next controller
destination?.list.append(newEntry)
} else {
let obj = defaults.object(forKey: "listarray") as? [String] ?? [String]()
destination?.list = obj.append(newEntry)
}
defaults.set(destination?.list, forKey: "listarray")
UserDefaults.standard.synchronize()