Table View is empty when I switch Tab Bar controller screens - ios

Question

I have a Tab bar Controller to manage all the views. The problem I'm having is when I call a function in searchViewController (doAThing()) from HomeViewController which reloads the tableView in searchViewController, the tableView is empty when the Tab bar controller switches views.
Why does calling the doAThing method in my searchViewController not refresh my tableView?
How can I fill my tableView with values.
HomeViewController.swift
import UIKit
class HomeViewController: UIViewController, UICollectionViewDelegate, UICollectionViewDataSource, UISearchBarDelegate{
#IBOutlet weak var productCollectionView: UICollectionView!
#IBOutlet weak var storesCollectionView: UICollectionView!
#IBOutlet var searchQ: UISearchBar!
#IBOutlet weak var scrollView: UIScrollView!
func collectionView(_ collectionView: UICollectionView, numberOfItemsInSection section: Int) -> Int {
if(collectionView == storesCollectionView) {
return storesImages.count
}
return productsImages.count
}
func collectionView(_ collectionView: UICollectionView, cellForItemAt indexPath: IndexPath) -> UICollectionViewCell {
if(collectionView == storesCollectionView) {
let cell2 = storesCollectionView.dequeueReusableCell(withReuseIdentifier: "storesCell", for: indexPath) as! StoreCollectionViewCell
cell2.compstoreImage.image = UIImage(named: storesImages[indexPath.row])
return cell2
}
else{
let cell = productCollectionView.dequeueReusableCell(withReuseIdentifier: "productsCell", for: indexPath) as! ProductCollectionViewCell
cell.pillImage.image = UIImage(named: productsImages[indexPath.row])
return cell
}
}
var productsImages:[String] = ["pcPic", "picturePC"]
var storesImages:[String] = ["newarkStore", "compeStore"]
override func viewDidLoad() {
super.viewDidLoad()
searchQ.delegate = self
scrollView.contentSize = CGSize(width: self.view.frame.width, height: self.view.frame.height)
// searchQ.delegate = self
// Do any additional setup after loading the view.
}
override func viewWillAppear(_ animated: Bool) {
super.viewWillAppear(animated)
//self.tabBarController?.tabBar.isHidden = false
}
func searchBarSearchButtonClicked(_ searchQ: UISearchBar)
{
print("*********")
let storyBoard : UIStoryboard = UIStoryboard(name: "Main", bundle:nil)
let resultViewController = storyBoard.instantiateViewController(withIdentifier: "SearchViewController") as! searchViewController
// resultViewController.searchQuery = searchQ
resultViewController.doAthing(searchQ)
self.tabBarController?.selectedIndex = 3
// NotificationCenter.default.post(name: NSNotification.Name(rawValue: "load"), object: nil)
resultViewController.resultsView.reloadData()
}
// func searchBarSearchButtonClicked(_ searchBar: UISearchBar) {
//
// print("*********")
//
// let secondViewController = self.storyboard?.instantiateViewController(withIdentifier: "SearchViewController") as! searchViewController
// secondViewController.doAthing(searchBar)
// self.navigationController!.pushViewController(secondViewController, animated: true)
//
//
//
// //let titles: Elements = try doc.select("a[product-thumb]")
// //let titles: String = try doc.select("a").attr("product-thumb")
//
// // print(titles
//
// hideKeyboardWhenTappedAround()
//
// }
/*
// MARK: - Navigation
// In a storyboard-based application, you will often want to do a little preparation before navigation
override func prepare(for segue: UIStoryboardSegue, sender: Any?) {
// Get the new view controller using segue.destination.
// Pass the selected object to the new view controller.
}
*/
}
searchViewController.swift
import UIKit
import SwiftSoup
class searchViewController: UIViewController{
#IBOutlet weak var segmentedControl: UISegmentedControl!
#IBOutlet weak var resultsView: UITableView!
#IBOutlet var searchQuery: UISearchBar!
// let content = try! String(contentsOf: URL(string: "https://www.locally.com/search/all/activities/depts?q=bottle")!)
// let doc: Document = try! SwiftSoup.parse(content)
var products: [String] = []
//let products = ["Computer", "PC", "Laptop"]
let stores = ["Computer Central", "Fry's Electronics", "Best Buy"]
//var stores: [String] = []
let into = ["Custom PC with high performanc. Perfect for gaming and streaming. Great condition", "Custom PC with high performanc. Perfect for gaming and streaming. Great condition", "Custom PC with high performanc. Perfect for gaming and streaming. Great condition"]
var dollars: [String] = []
//let dollars = [100, 220, 129, 100, 220, 129]
let likes = [10, 24, 24, 24 , 456, 46, 46]
//let miles = ["3.2 mi", "4.1 mi", "6.3 mi", "3.2 mi", "4.1 mi", "6.3 mi"]
var miles: [String] = []
// let names = ["Central Computers", "CompE", "geekStore", "Central Computers", "CompE", "geekStore"]
var names: [String] = []
let numbers = ["510-329-0172", "510-456-7345", "510-329-0172", "510-329-0172", "510-456-7345", "510-329-0172"]
var images: [UIImage] = []
var categories: [String] = []
var descriptions: [String] = []
var stars: [String] = []
var ratings: [Double] = []
var ratingImage: [[UIImage]] = [[]]
var phones: [String] = []
var cities: [String] = []
//var webCounter:Int = 0
var x:Double = 0
var y:Int = 0
override func viewDidLoad() {
super.viewDidLoad()
NotificationCenter.default.addObserver(self, selector: #selector(loadList), name: NSNotification.Name(rawValue: "load"), object: nil)
searchQuery.delegate = self
resultsView.delegate = self
resultsView.dataSource = self
//set the height of each row in tableview
self.resultsView.rowHeight = 200.0
// Do any additional setup after loading the view.
}
#objc func loadList(notification: NSNotification) {
//load data here
self.resultsView.reloadData()
}
func searchBarSearchButtonClicked(_ searchBar: UISearchBar) {
//searchBar.inputViewController?.dismissKeyboard()
searchBar.inputViewController?.dismiss(animated: true)
doAthing(searchBar)
self.searchQuery.endEditing(true)
self.resultsView.keyboardDismissMode = .onDrag
hideKeyboardWhenTappedAround()
}
func doAthing(_ searchBar: UISearchBar) {
do {
let alert = UIAlertController(title: nil, message: "Please wait...", preferredStyle: .alert)
let loadingIndicator = UIActivityIndicatorView(frame: CGRect(x: 10, y: 5, width: 50, height: 50))
loadingIndicator.hidesWhenStopped = true
loadingIndicator.style = UIActivityIndicatorView.Style.medium
loadingIndicator.startAnimating();
alert.view.addSubview(loadingIndicator)
present(alert, animated: true, completion: nil)
print("reached here")
let html = try String(contentsOf: URL(string: "https://www.locally.com/search/all/activities/depts?q=" + searchBar.text!)!)
//let doc: Document = try SwiftSoup.parse(html)
guard let titles: Elements = try? SwiftSoup.parse(html).getElementsByClass("product-thumb ") else {return}//select("a") else {return}
guard let prices: Elements = try? SwiftSoup.parse(html).getElementsByClass("product-thumb-price dl-price") else {return}
guard let Stores: Elements = try? SwiftSoup.parse(html).getElementsByClass("filter-label-link") else {return}
guard let Images: Elements = try? SwiftSoup.parse(html).getElementsByClass("product-thumb-img") else {return}
products = []
miles = []
dollars = []
names = []
images = []
stars = []
for title: Element in titles.array() {
print("title" + String(titles.size()))
products.append(try! title.attr("data-product-name"))
guard let url: URL = try? URL(string: "https://www.locally.com/" + String(try! title.attr("href")))
else
{
miles.append("-")
continue
}
let html1 = try String(contentsOf: url)
guard let distances: Element = try? SwiftSoup.parse(html1).getElementsByClass("conv-section-distance dl-store-distance").first()
else
{
miles.append("-")
continue
}
print(try! distances.ownText())
miles.append(try! distances.ownText())
guard let K: Array<String> = try? SwiftSoup.parse(html1).getElementsByClass("breadcrumbs container").eachText() else {return}
let str = (try! K.last!.components(separatedBy: "/") )
categories.append(str[str.count - 2])
print(str[str.count - 2])
guard let desc: Array<String> = try? SwiftSoup.parse(html1).getElementsByClass("pdp-information").eachText() else {return}
guard let s:String = try? desc[1]
else {
return
}
descriptions.append( String( s.suffix(s.count - 19) ) )
print( String( s.suffix(s.count - 19) ) )
guard let star: Element = try? SwiftSoup.parse(html1).getElementsByClass("stars").first()
else
{
print("no reviews")
ratings.append(0)
continue
}
print(try! star.attr("data-rating"))
//ratings.append(try! star.attr("data-rating")) ?? ()
let x = Double(try! star.attr("data-rating")) ?? 0
print("y: " + String(Int(x)))
ratings.append(x)
guard let locations: Element = try? SwiftSoup.parse(html1).getElementsByClass("conv-section-store-address section-subtitle dl-store-address js-store-location").first()
else
{
print("cant find city")
return
}
let string = locations.ownText()
print("location: " + String(string.prefix(string.count - 10)) )
cities.append(try! String(string.prefix(string.count - 10)))
guard let phoneNums: Element = try? SwiftSoup.parse(html1).getElementsByClass("selected-retailer-info-link btn-action-sm tooltip").first()
else
{
print("link not found")
return
}
guard let urls:URL = try? URL(string: "https://www.locally.com/" + phoneNums.attr("href") )
else
{
return
}
let html2 = try String(contentsOf: urls )
guard let storePage:Element = try? SwiftSoup.parse(html2).getElementsByClass("landing-page-phone-label").first() else {
print("Phone Number not found")
return
}
let sp = try? storePage.ownText
if let s = sp {
phones.append(try! s())
}
else {
phones.append("N/A")
}
print(try! storePage.ownText())
//
// let html1 = try String(contentsOf: url)
}
for price: Element in prices.array() {
print("prices" + String(prices.size()))
print(String(try! price.ownText()))
dollars.append(try! price.ownText())
}
for store: Element in Stores.array() {
print("Stores" + String(Stores.size()))
names.append(try! store.ownText()) ?? names.append("N/A")
}
for image: Element in Images.array() {
guard let url = URL(string: try! image.attr("src") ) else { return }
let data = try? Data(contentsOf: url)
if let imageData = data {
images.append( UIImage(data: imageData)! )
}
else {
images.append(UIImage(named: "pcPic")!)
}
//images.append(try! image.downloaded(from: image.attr("src")))
}
dismiss(animated: false, completion: nil)
resultsView.reloadData()
//let titles: Elements = try doc.select("a[product-thumb]")
//let titles: String = try doc.select("a").attr("product-thumb")
// print(titles)
} catch Exception.Error(type: let type, Message: let message) {
print(type)
print(message)
} catch {
print("")
}
}
// override func viewWillAppear(_ animated: Bool) {
// super.viewWillAppear(animated)
// self.tabBarController?.tabBar.isHidden = false
// }
//When user changes segment, tableview is reloaded
#IBAction func segmentChanged(_ sender: Any) {
resultsView.reloadData();
}
/*
// MARK: - Navigation
// In a storyboard-based application, you will often want to do a little preparation before navigation
override func prepare(for segue: UIStoryboardSegue, sender: Any?) {
// Get the new view controller using segue.destination.
// Pass the selected object to the new view controller.
}
*/
func imageWithImage(image: UIImage, scaledToSize newSize: CGSize) -> UIImage {
UIGraphicsBeginImageContext(newSize)
image.draw(in: CGRect(x: 0 ,y: 20 ,width: newSize.width ,height: newSize.height))
let newImage = UIGraphicsGetImageFromCurrentImageContext()
UIGraphicsEndImageContext()
return newImage!.withRenderingMode(.alwaysOriginal)
}
}
extension searchViewController: UITableViewDelegate, UITableViewDataSource, UISearchBarDelegate {
func tableView(_ tableView: UITableView, numberOfRowsInSection section: Int) -> Int {
print("reached here")
switch segmentedControl.selectedSegmentIndex {
case 0:
return products.count
case 1:
return stores.count
case 2:
return (products.count + stores.count)
default:
break
}
return 0
}
func tableView(_ tableView: UITableView, cellForRowAt indexPath: IndexPath) -> UITableViewCell {
let cell = tableView.dequeueReusableCell(withIdentifier: "resultsTableViewCell") as! resultsTableViewCell
switch segmentedControl.selectedSegmentIndex {
case 0:
cell.titleLabel?.text = products[indexPath.row]
cell.productImage?.image = images[indexPath.row]
// cell.descriptionLabel?.text = into[indexPath.row]
// cell.descriptionLabel?.numberOfLines = 0
cell.price?.text = String(dollars[indexPath.row])
cell.distance?.text = miles[indexPath.row]
cell.storeName?.numberOfLines = 0
cell.storeName?.text = names[indexPath.row]
cell.phoneNumber?.text = phones[indexPath.row]
let ratNumber = ratings[indexPath.row]
if( ratNumber == 0 )
{
cell.rating?.text = "No Reviews"
}
else
{
cell.rating?.text = String(ratNumber)
}
if(ratNumber > 4.5)
{
cell.star1.image = UIImage(named: "regular_5")
}
else if(ratNumber > 4.0)
{
cell.star1.image = UIImage(named: "regular_4_half")
}
else if(ratNumber == 4.0)
{
cell.star1.image = UIImage(named: "regular_4")
}
else if(ratNumber > 3.0)
{
cell.star1.image = UIImage(named: "regular_3_half")
}
else if(ratNumber == 3.0)
{
cell.star1.image = UIImage(named: "regular_3")
}
else if(ratNumber > 2.0)
{
cell.star1.image = UIImage(named: "regular_2_half")
}
else if(ratNumber == 2.0)
{
cell.star1.image = UIImage(named: "regular_2")
}
else if(ratNumber > 1.0)
{
cell.star1.image = UIImage(named: "regular_1_half")
}
else if(ratNumber == 1.0)
{
cell.star1.image = UIImage(named: "regular_1")
}
else
{
cell.star1.image = UIImage(named: "regular_0")
}
cell.rating?.numberOfLines = 0
// cell.phoneNumber?.text = numbers[indexPath.row]
case 1:
cell.titleLabel?.text = stores[indexPath.row]
cell.productImage?.image = imageWithImage(image: UIImage.init(named: "pcPic")!, scaledToSize: CGSize(width: 400, height: 300))
// cell.descriptionLabel?.text = into[indexPath.row]
// cell.descriptionLabel?.numberOfLines = 0
cell.price?.text = String(dollars[indexPath.row])
cell.distance?.text = miles[indexPath.row]
cell.storeName?.text = names[indexPath.row]
cell.phoneNumber?.text = numbers[indexPath.row]
case 2:
var all = products + stores
all.shuffle()
let alls = into + into
cell.titleLabel?.text = all[indexPath.row]
cell.productImage?.image = imageWithImage(image: UIImage.init(named: "pcPic")!, scaledToSize: CGSize(width: 400, height: 300))
// cell.descriptionLabel?.text = alls[indexPath.row]
// cell.descriptionLabel?.numberOfLines = 0
cell.price?.text = String(dollars[indexPath.row])
cell.distance?.text = miles[indexPath.row]
cell.storeName?.text = names[indexPath.row]
cell.phoneNumber?.text = numbers[indexPath.row]
default:
break
}
return cell
}
func tableView(_ tableView: UITableView, didSelectRowAt indexPath: IndexPath) {
// let vc = self.storyboard?.instantiateViewController(withIdentifier: "ShopViewController") as! ShopViewController
// self.present(vc, animated: true, completion: nil)
let storyboard = UIStoryboard(name: "Main", bundle: nil)
let destinationVC = storyboard.instantiateViewController(withIdentifier: "ProductViewController") as! ProductViewController
destinationVC.ktitle = products[indexPath.row]
destinationVC.kprice = dollars[indexPath.row]
// destinationVC.kdescription = [indexPath.row]
destinationVC.kimage = images[indexPath.row]
// destinationVC.klikes = likes[indexPath.row]
destinationVC.kcategory = categories[indexPath.row]
destinationVC.kdescription = descriptions[indexPath.row]
destinationVC.kname = names[indexPath.row]
destinationVC.kmiles = miles[indexPath.row]
destinationVC.klocation = cities[indexPath.row]
self.present(destinationVC, animated: true, completion: nil)
}
}
extension UIViewController {
func hideKeyboardWhenTappedAround() {
let tap: UITapGestureRecognizer = UITapGestureRecognizer(target: self, action: #selector(UIViewController.dismissKeyboard(_:)))
tap.cancelsTouchesInView = false
view.addGestureRecognizer(tap)
}
#objc func dismissKeyboard(_ sender: UITapGestureRecognizer) {
view.endEditing(true)
if let nav = self.navigationController {
nav.view.endEditing(true)
}
}
}

Answer 1

First, it's probably not a good idea to switch to a different tab in that manner. Users understand that tapping a tab-bar icon/button takes them to a new tab. If you're jumping around in the tabs via code, it can be very confusing for the user.
But... it's your app.
The reason your code does not "refresh my tableView" is because you never actually reference that view controller.
In your code:
func searchBarSearchButtonClicked(_ searchQ: UISearchBar)
{
print("*********")
let storyBoard : UIStoryboard = UIStoryboard(name: "Main", bundle:nil)
// here you create a NEW instance of searchViewController
let resultViewController = storyBoard.instantiateViewController(withIdentifier: "SearchViewController") as! searchViewController
// you call a func in that instance
resultViewController.doAthing(searchQ)
// you switch to tab index 3, which holds an OLD instance of searchViewController
self.tabBarController?.selectedIndex = 3
// you tell resultsView in the NEW instance to reloadData()
resultViewController.resultsView.reloadData()
// as soon as you exit this func, the NEW instance is deleted
}
You could do something like this:
func searchBarSearchButtonClicked(_ searchQ: UISearchBar)
print("*********")
// get a reference to the searchViewController that is already
// part of the tab bar controller
if let tb = self.tabBarController,
let controllers = tb.viewControllers,
let resultVC = controllers[3] as? searchViewController {
// call the func
resultVC.doAthing("new")
tb.selectedIndex = 3
}
}
However, that's really not a great approach... Just for one example, Suppose you change the order of the tabs at some point?
You're better off using either a custom tab bar controller class, or using a "data manager" class.
I'd suggest you head over to google (or your favorite search engine) and search for swift pass data between tab bar view controllers -- you'll find plenty of discussions, articles, examples, etc.
Edit -- comment
In HomeViewController replace your func searchBarSearchButtonClicked with this:
func searchBarSearchButtonClicked(_ searchQ: UISearchBar)
{
print("1 - searchBarSearchButtonClicked")
guard let btnTitle = searchQ.largeContentTitle else {
print("2 - FAILED to get searchQ.largeContentTitle")
return
}
print("2 - got btnTitle", btnTitle)
if let tb = self.tabBarController {
print("3 - got a tab bar controller reference")
if let controllers = tb.viewControllers {
print("4 - got controllers reference")
if controllers.count == 4 {
print("5 - we have 4 controllers")
if let resultVC = controllers[3] as? searchViewController {
print("6 - got a reference to searchViewController")
// if we have not yet selected the 4th tab,
// the view will not yet have been loaded
// so make sure it is
resultVC.loadViewIfNeeded()
// call the func, passing the button title
resultVC.doAthing(searchQ)
// switch to the 4th tab
tb.selectedIndex = 3
print("7 - we should now be at searchViewController")
} else {
print("6 - FAILED TO GET a reference to searchViewController")
}
} else {
print("5 - FAILED TO GET a reference to searchViewController")
}
} else {
print("4 - FAILED TO GET a reference to searchViewController")
}
} else {
print("3 - FAILED TO GET a reference to searchViewController")
}
}
Then see what messages get printed to the debug console.