Swift prepareForSegue object is nil - ios

I'm trying to pass the event Object into DetailViewController, but it crashes and says: "fatal error: unexpectedly found nil while unwrapping an Optional value". I'm positive the error is in my prepare(for segue:) function, but I've been at this for hours and I can't find out how to fix it. Any help would be appreciated. Thanks!
Here is my code:
class MainViewController: UIViewController, UITableViewDataSource, UITableViewDelegate {
#IBOutlet weak var textView: UITextView!
#IBOutlet weak var tableView: UITableView!
var events = [Event]()
override func viewDidLoad() {
super.viewDidLoad()
// Do any additional setup after loading the view.
tableView.delegate = self
tableView.dataSource = self
parseCSV()
}
override func didReceiveMemoryWarning() {
super.didReceiveMemoryWarning()
// Dispose of any resources that can be recreated.
}
#IBAction func logOutAction(sender: AnyObject) {
if FIRAuth.auth()?.currentUser != nil {
do {
try FIRAuth.auth()?.signOut()
let vc = UIStoryboard(name: "Main", bundle: nil).instantiateViewController(withIdentifier: "SignUp")
present(vc, animated: true, completion: nil)
} catch let error as NSError {
print(error.localizedDescription)
}
}
}
func parseCSV() {
let path = Bundle.main.path(forResource: "eventData", ofType: "csv")
do {
let csv = try CSV(contentsOfURL: path!)
let rows = csv.rows
for row in rows {
let eventTitle = row["Title "]!
let eventLoc = row[" Location "]!
let eventStart = row[" Start_Time "]!
let eventEnd = row [" End_Time"]!
let event = Event(title: eventTitle, loc: eventLoc, start: eventStart, end: eventEnd)
events.append(event)
}
} catch let err as NSError {
print(err.debugDescription)
}
}
func tableView(_ tableView: UITableView, cellForRowAt indexPath: IndexPath) -> UITableViewCell {
if let cell = tableView.dequeueReusableCell(withIdentifier: "eventCell", for: indexPath) as? EventCell{
let event = events[indexPath.row]
cell.updateUI(event: event)
return cell
} else {
return UITableViewCell()
}
}
func tableView(_ tableView: UITableView, numberOfRowsInSection section: Int) -> Int {
return events.count
}
func tableView(_ tableView: UITableView, didSelectRowAt indexPath: IndexPath) {
let event = events[indexPath.row]
performSegue(withIdentifier: "detailSegue", sender: event)
}
override func prepare(for segue: UIStoryboardSegue, sender: Any?) {
if segue.identifier == "detailSeque" {
if let detailVC = segue.destination as? DetailViewController {
if let event = sender as? Event {
detailVC.event = event
}
}
}
}
}
My DetailViewController class:
class DetailViewController: UIViewController {
var event: Event!
#IBOutlet weak var eventTitle: UILabel!
override func viewDidLoad() {
super.viewDidLoad()
eventTitle.text = event.title // error here. says event is nil.
}
}

Since the segue is connected from your cell, it already performed automatically when you tap the cell. Performing it programmatically is resulting in your segue being performed twice: once with the value passed correctly and once without.
You can either change your segue to be connected from the view controller instead of the cell in which case your current code would work, or update your code to do all of the logic in prepareForSegue and remove your implementation of didSelectRowAt:
override func prepare(for segue: UIStoryboardSegue, sender: Any?) {
if segue.identifier == "detailSeque" {
if let detailVC = segue.destination as? DetailViewController {
let row = tableView.indexPathForSelectedRow!.row
detailVC.event = events[row]
}
}
}

Related

Swift: Show data from tableView to another ViewController (JSON, Alamorife, AlamofireImage)

I'm trying to do an app in which the data were obtained from JSON.
In the picture below you can see the project:
Project
If we click on the photo opens the details page. The problem is because I do not know how to pick up the data shown in the details page. Please help me.
Here is the code
import UIKit
import Alamofire
import AlamofireImage
import SwiftyJSON
class ViewController: UIViewController ,UITableViewDelegate,UITableViewDataSource,UISearchBarDelegate {
#IBOutlet weak var searchbarValue: UISearchBar!
weak open var delegate: UISearchBarDelegate?
#IBOutlet weak var tableView: UITableView!
var albumArray = [AnyObject]()
var url = ("https://jsonplaceholder.typicode.com/photos")
override func viewDidLoad() {
super.viewDidLoad()
// Do any additional setup after loading the view, typically from a nib.
self.searchbarValue?.delegate = self
Alamofire.request("https://jsonplaceholder.typicode.com/photos").responseJSON { (responseData) -> Void in
if((responseData.result.value) != nil) {
let swiftyJsonVar = JSON(responseData.result.value!)
if let resData = swiftyJsonVar[].arrayObject {
self.albumArray = resData as [AnyObject]; ()
}
if self.albumArray.count > 0 {
self.tableView.reloadData()
}
}
}
}
public func searchBarTextDidEndEditing(_ searchBar: UISearchBar) // called when text ends editing
{
callAlamo(searchTerm: searchbarValue.text!)
}
func callAlamo(searchTerm: String)
{
Alamofire.request("https://jsonplaceholder.typicode.com/photos").responseJSON { (responseData) -> Void in
if((responseData.result.value) != nil) {
let swiftyJsonVar = JSON(responseData.result.value!)
if let resData = swiftyJsonVar[].arrayObject {
self.albumArray = resData as [AnyObject]; ()
}
if self.albumArray.count > 0 {
self.tableView.reloadData()
}
}
}
}
func tableView(_ tableView: UITableView, numberOfRowsInSection section: Int) -> Int {
return albumArray.count
}
func tableView(_ tableView: UITableView, cellForRowAt indexPath: IndexPath) -> UITableViewCell {
let cell = tableView.dequeueReusableCell(withIdentifier: "cell", for: indexPath) as? CostumTableViewCell
let title = albumArray[indexPath.row]
cell?.titleLabel?.text = title["title"] as? String
//cell?.url?.image = UIImage(data: title as! Data)
let imageUrl = title["thumbnailUrl"] as? String
//print(imageUrl)
let urlRequest = URLRequest(url: URL(string: imageUrl!)!)
Alamofire.request(urlRequest).responseImage { response in
if let image = response.result.value {
// print("image downloaded: \(title["url"])")
cell?.url?.image = image
}
}
return cell!
}
func tableView(_ tableView: UITableView, didSelectRowAt indexPath: IndexPath) {
performSegue(withIdentifier: "showDetails", sender: self)
}
override func prepare(for segue: UIStoryboardSegue, sender: Any?) {
let indexPath = self.tableView.indexPathForSelectedRow?.row
let vc = segue.destination as! DetailsViewController
//here should be the code
}
override func didReceiveMemoryWarning() {
super.didReceiveMemoryWarning()
// Dispose of any resources that can be recreated.
}
}
Also you can see the DetailsViewController code:
import UIKit
class DetailsViewController: UIViewController {
var image2 = UIImage()
var title2 = String()
#IBOutlet var mainImageView: UIImageView!
#IBOutlet var songTitle: UILabel!
override func viewDidLoad() {
songTitle.text = title2
mainImageView.image = image2
}
}
You can easily pass value from tableview to detail view using the below code :
override func prepare(for segue: UIStoryboardSegue, sender: Any?) {
let indexPath = self.tableView.indexPathForSelectedRow
let cell : CostumTableViewCell = self.tableView.cellForRow(at: indexPath!) as! CostumTableViewCell
let vc = segue.destination as! DetailsViewController
vc.image2 = cell.url.image!
vc.title2 = cell.titleLabel.text!
}
class ViewController: UIViewController ,UITableViewDelegate,UITableViewDataSource,UISearchBarDelegate {
var customArr = [CustomElement]()
var arr = [Any]()
// In viewDidLoad , you can append element to customArr
func tableView(_ tableView: UITableView, didSelectRowAt indexPath: IndexPath) {
var image = customArr[indexpath.row].image
var title = customArr[indexpath.row].title
arr.append(image)
arr.append(title)
performSegue(withIdentifier: "showDetails", sender: arr)
}
override func prepare(for segue: UIStoryboardSegue, sender: Any?) {
let indexPath = self.tableView.indexPathForSelectedRow?.row
if segue.identifier = "showDetails" {
if let vc = segue.destination as! DetailsViewController {
vc.arr = sender
}
}
//here should be the code
}
}
class DetailsViewController: UIViewController {
var arr = [Any]()
}

How do i navigate to another view from search results displayed in table view?

The following code is my viewController code. The words from the json file are displayed in a tableView on click of a word it is taken to another page where elements associated with that word are displayed. However i am not able to navigate to that page when the search results are displayed in table view.
class ViewController: UIViewController, UITableViewDelegate, UITableViewDataSource, UISearchResultsUpdating{
#IBOutlet weak var mainTableView: UITableView!
var words = [wordStats]()
var filteredArray = [wordStats]()
var searchController = UISearchController()
var resultsController = UITableViewController()
override func viewDidLoad() {
super.viewDidLoad()
// Do any additional setup after loading the view, typically from a nib.
getJson {
self.mainTableView.reloadData()
}
mainTableView.delegate = self
mainTableView.dataSource = self
searchController = UISearchController(searchResultsController: resultsController)
mainTableView.tableHeaderView = searchController.searchBar
searchController.searchResultsUpdater = self
resultsController.tableView.delegate = self
resultsController.tableView.dataSource = self
}
func updateSearchResults(for searchController: UISearchController) {
filteredArray = words.filter({ (words: wordStats) -> Bool in
if words.word.contains(searchController.searchBar.text!){
return true
}else{
return false
}
})
resultsController.tableView.reloadData()
}
func tableView(_ tableView: UITableView, numberOfRowsInSection section: Int) -> Int {
if tableView == resultsController.tableView{
return filteredArray.count
}else{
return words.count
}
}
func tableView(_ tableView: UITableView, cellForRowAt indexPath: IndexPath) -> UITableViewCell {
let cell = UITableViewCell(style: .default, reuseIdentifier: nil)
if tableView == resultsController.tableView{
cell.textLabel?.text = filteredArray[indexPath.row].word.capitalized
}else{
cell.textLabel?.text = words[indexPath.row].word.capitalized
}
//cell.textLabel?.text = words[indexPath.row].word.capitalized
return cell
}
func tableView(_ tableView: UITableView, didSelectRowAt indexPath: IndexPath) {
performSegue(withIdentifier: "wordDetails", sender: self)
}
override func prepare(for segue: UIStoryboardSegue, sender: Any?) {
if let destination = segue.destination as? HeroViewController{
destination.word = words[(mainTableView.indexPathForSelectedRow?.row)!]
}
}
func getJson(completed: #escaping () -> ()){
let path = Bundle.main.path(forResource: "week_14", ofType: "json")
let url = URL(fileURLWithPath: path!)
let data = try! Data(contentsOf: url)
do {
self.words = try JSONDecoder().decode([wordStats].self, from: data)
DispatchQueue.main.async{
completed()
}
}catch{
print("JSON error")
}
}
}
Initially after getting the data from the JSON file the data is displayed in mainTableView but after searching when i click on the item app crashes. Can someone help me out please?
struct wordStats:Decodable{
let word: String
let synonym: String
let meaning: String
let example: String
let video: String
}
this is the wordStats
Post the crash log. My guess based on what little we have here is that you are crashing in prepareForSegue on this:
destination.word = words[(mainTableView.indexPathForSelectedRow?.row)!]
It's probably an index error when using the filtered results. This might address it:
override func prepare(for segue: UIStoryboardSegue, sender: Any?) {
if let destination = segue.destination as? HeroViewController{
if tableView == resultsController.tableView {
destination.word = filteredArray[(mainTableView.indexPathForSelectedRow?.row)!]
} else {
destination.word = words[(mainTableView.indexPathForSelectedRow?.row)!]
}
}
}
This is what worked in the end
override func prepare(for segue: UIStoryboardSegue, sender: Any?) {
if let destination = segue.destination as? HeroViewController {
if let indexPath = mainTableView.indexPathForSelectedRow{
if isFiltering(){
destination.word = filteredArray[indexPath.row]
}else{
destination.word = words[indexPath.row]
}
}
}
}

Parse from TableVC to textView in other viewController swift

I am new in programming, and have problem. I am using parse for my array in tableview. When the row is selected i want to segue on another view controller to textView. The tableview works good but i can't get text to textView.
tableVC:
import UIKit
import Parse
class ThirdTableVC: UITableViewController {
#IBOutlet weak var refresherQuotes: UIRefreshControl!
#IBOutlet var quoteTable: UITableView!
var selectedQuote: PFObject?
var quoteItems = [PFObject]()
override func viewDidLoad() {
super.viewDidLoad()
}
#IBAction func updateQuotesResults(_ sender: UIRefreshControl) {
fetchQuotesData()
}
override func viewWillAppear(_ animated: Bool) {
super.viewWillAppear(animated)
loadQuoteTexts(selectedQuote: selectedQuote)
}
override func didReceiveMemoryWarning() {
super.didReceiveMemoryWarning()
}
// MARK: - Table view data source
override func numberOfSections(in tableView: UITableView) -> Int {
return 1
}
override func tableView(_ tableView: UITableView, numberOfRowsInSection section: Int) -> Int {
return quoteItems.count
}
func fetchQuotesData() {
let quotesQuery = PFQuery(className: "TotalTest")
quotesQuery.whereKey("Subcategory", equalTo: selectedQuote ?? nil)
quotesQuery.findObjectsInBackground { (objects, error) in
if let realCategoryObjects = objects {
self.quoteItems = realCategoryObjects
self.tableView.reloadData()
self.refresherQuotes.endRefreshing()
}
}
}
override func tableView(_ tableView: UITableView, cellForRowAt indexPath: IndexPath) -> UITableViewCell {
let quoteCell = tableView.dequeueReusableCell(withIdentifier: "quoteCell", for: indexPath)
let quoteItem = quoteItems[indexPath.row]
let quoteUserTitle = quoteItem.object(forKey: "TextQuote") as? String
quoteCell.textLabel?.text = quoteUserTitle
return quoteCell
}
override func prepare(for segue: UIStoryboardSegue, sender: Any?) {
if segue.identifier == "showQuoteDetail" {
if let indexPath = tableView.indexPathForSelectedRow {
let quoteobject = quoteItems[indexPath.row] as? NSDate
let quoteController = (segue.destination as! UINavigationController).topViewController as! DetailViewController
quoteController.detailItem = quoteobject
quoteController.navigationItem.leftBarButtonItem = splitViewController?.displayModeButtonItem
quoteController.navigationItem.leftItemsSupplementBackButton = true
}
}
}
override func tableView(_ tableView: UITableView, didSelectRowAt indexPath: IndexPath) {
print("Row tapped: \(indexPath.row)")
let selectedQuotes: PFObject = quoteItems[indexPath.row]
let FourthVC = self.storyboard?.instantiateViewController(withIdentifier: "FourthViewController") as! FourthViewController
FourthVC.fourthTextView.text = quoteItems[indexPath.row] as? String
self.navigationController?.pushViewController(FourthVC, animated: true)
}
func loadQuoteTexts(selectedQuote: PFObject!) {
let quoteQuery = PFQuery(className: "TotalQuote")
quoteQuery.whereKey("QuoteSubs", equalTo: selectedQuote ?? nil)
quoteQuery.includeKey("QuoteSubs")
quoteQuery.findObjectsInBackground { (result: [PFObject]?, error) in
if let searchQuoteResults = result {
self.quoteItems = searchQuoteResults
self.quoteTable.reloadData()
}
}
}
}
How can I change this?
viewController with textView:
import UIKit
import Parse
class FourthViewController: UIViewController {
var getQuote: PFObject?
#IBOutlet weak var fourthTextView: UITextView!
#IBOutlet weak var fourthLabel: UILabel!
override func viewDidLoad() {
super.viewDidLoad()
fourthLabel.text! = getQuote as! String
fourthTextView.text! = getQuote as! String
}
}
Please help me to passing texts
If you use pushViewController do it like that , in did selectRowAt
let MainStory: UIStoryboard = UIStoryboard(name: "Main", bundle: nil)
let desVC = MainStory.instantiateViewController(withIdentifier: "FourthViewController") as! FourthViewController
and now pass your text
desVC.getText = "here goes your text u want to pass"
FourthViewController
set up your var
var getText = String()
so you can finally use
self.navigationController?.pushViewController(desVC, animated: true)
so it will pass all parameters you previous add with desVC.getSomething
in FourthViewController you just need to use getText.
The problem is that you are changing from a view to another with pushViewController, by doing that your prepareForSegue won't be executed.
On your didSelectRow you need to call performSegue(withIdentifier:sender:).
You can lookup this question for more information on how to do it.

Passing data back to previous view controller after selecting table view cell

I'm having trouble passing data after selecting a table view cell to the previous view controller. I'm pretty much trying to change a label from the previous view controller after selecting a table view cell. Could anyone help me go about this? I'm trying to change the UITextField after selecting a cell.
UIViewController:
class WhoToOdds: UIViewController, sendBack,UITextFieldDelegate{
#IBOutlet var chosenContact: UITextField!
#IBOutlet var oddsTextBox: UITextView!
var friend: String?
override func viewWillAppear(animated: Bool) {
super.viewWillAppear(animated)
navigationController?.setNavigationBarHidden(false, animated: true)
}
func sendNameToPreviousVC(selectedfriendName: String) {
friend = selectedfriendName
chosenContact.text = friend
}
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 prepareForSegue(segue: UIStoryboardSegue, sender: AnyObject?) {
if segue.identifier == "friendList"{
let friendViewController = (segue.destinationViewController as! friendListController)
var fbRequest = FBSDKGraphRequest(graphPath:"/me/friends", parameters: nil);
fbRequest.startWithCompletionHandler { (connection : FBSDKGraphRequestConnection!, result : AnyObject!, error : NSError!) -> Void in
if error == nil {
println("Friends are : \(result)")
PFUser.currentUser()?["friend_list"] = result
PFUser.currentUser()?.save()
print(result)
var resultdict = result as! NSDictionary
println("Result Dict: \(resultdict)")
friendViewController.friendArray = resultdict.objectForKey("data") as! NSArray
} }
}
}
#IBAction private func submitChallenge(sender: AnyObject) {
navigationController?.popViewControllerAnimated(true)
}
}
TableViewController:
protocol sendBack
{
func sendNameToPreviousVC(contact: String)
}
class friendListController: UITableViewController, UITableViewDataSource, UITableViewDelegate{
var friendArray:NSArray = ["a","b","c"]
var valueDict:NSDictionary = [:]
var mDelegate:sendBack?
var selectedFriend :String?
override func viewWillAppear(animated: Bool) {
super.viewWillAppear(animated)
navigationController?.setNavigationBarHidden(false, animated: true)
}
override func viewDidLoad() {
super.viewDidLoad()
}
override func tableView(tableView: UITableView, numberOfRowsInSection section: Int) -> Int {
return friendArray.count
}
override func tableView(tableView: UITableView, cellForRowAtIndexPath indexPath: NSIndexPath) -> UITableViewCell {
let cell = tableView.dequeueReusableCellWithIdentifier("friend", forIndexPath: indexPath) as! UITableViewCell
cell.textLabel!.text = (friendArray[indexPath.row] as! String)
return cell
}
override func tableView(tableView: UITableView, didSelectRowAtIndexPath indexPath: NSIndexPath){
let indexPath = tableView.indexPathForSelectedRow();
let currentCell = tableView.cellForRowAtIndexPath(indexPath!) as UITableViewCell!
selectedFriend = currentCell.textLabel!.text as String!
sendBackFriendList(selectedFriend!)
navigationController?.popViewControllerAnimated(true)
}
func sendBackFriendList(name: String){
self.mDelegate?.sendNameToPreviousVC(name)
}
}
Your delegate needs to be set. In your case you have to set it inside prepareForSegue method like
override func prepareForSegue(segue: UIStoryboardSegue, sender: AnyObject?) {
if segue.identifier == "friendList"{
let friendViewController = (segue.destinationViewController as! friendListController)
friendViewController.mDelegate = self //Include this line
//rest of the code
}
}
You didn't set the delegate in your segue, so mDelegate is nil in your sendBackFriendList method

How do I pass the same textview, button, and label after clicking the Cell swift?

I would like to make it so that when the user clicks on the cell, it shows exactly everything in the cell. TextView, Buttons, and label. How can I do this?
Here is the code:
TableCell:
import UIKit
class TableViewCell: UITableViewCell {
#IBOutlet weak var textView: UITextView!
#IBAction func 1Button(sender: AnyObject) {
}
#IBAction func 2Button(sender: AnyObject) {
}
#IBOutlet weak var counter: UILabel!
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
}
}
TableViewController:
import UIKit
let reuseIdentifier = "Cell"
class UserFeedTableViewController: UITableViewController, ComposeViewControllerDelegate {
private var posts: [PFObject]? {
didSet {
tableView.reloadData()
}
}
override func viewDidLoad() {
super.viewDidLoad()
Downloader.sharedDownloader.queryForPosts()
NSNotificationCenter.defaultCenter().addObserver(self, selector: "queryFeeds:", name: queryNotification, object: nil)
}
// Notification SEL
func queryFeeds(notification: NSNotification) {
posts = notification.object as? [PFObject]
}
override func didReceiveMemoryWarning() {
super.didReceiveMemoryWarning()
// Dispose of any resources that can be recreated.
}
override func prepareForSegue(segue: UIStoryboardSegue, sender: AnyObject?) {
if segue.identifier == "postSegue" {
let nav = segue.destinationViewController as! UINavigationController
let composeVc = nav.topViewController as! ComposeViewController
composeVc.delegate = self
}
if segue.identifier == "commentsSegue" {
let vc = segue.destinationViewController as! CommentsViewController
let cell = sender as! UITableViewCell
let indexPath = tableView.indexPathForCell(cell)
let object = posts![indexPath!.row]
vc.postObject = object
}
}
//dismiss compose vc
func dismissComposeViewController(ViewController: ComposeViewController) {
dismissViewControllerAnimated(true, completion: nil)
}
func reloadTableViewAfterPosting() {
dismissViewControllerAnimated(true, completion: nil)
Downloader.sharedDownloader.queryForPosts()
}
}
extension ViewController {
override func tableView(tableView: UITableView, numberOfRowsInSection section: Int) -> Int {
// #warning Incomplete method implementation.
// Return the number of rows in the section.
return posts?.count ?? 0
}
override func tableView(tableView: UITableView, cellForRowAtIndexPath indexPath: NSIndexPath) -> UITableViewCell {
let cell = tableView.dequeueReusableCellWithIdentifier(reuseIdentifier, forIndexPath: indexPath) as! UserFeedTableViewCell
// Configure the cell...
if let posts = posts {
let object = posts[indexPath.row]
cell.textView?.text = object["post"] as? String
}
return cell
}

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