How to delete a row from tableview using custom buttom
//CustomCell.swift
protocol FavoriteCellDelegate {
func deleteButton(sender:CustomCell)
}
class FavoriteItemTableViewCell: UITableViewCell{
var delegate: FavoriteCellDelegate!
#IBAction func deleteButton(_ sender: UIButton) {
delegate.deleteButton(sender: self)
}
}
CustomClass:UITableViewDataSource,UITableViewDelegate,CustomCellDelegate{
#IBOutlet weak var tableView: UITableView!
// all necessary functions for table view....
// Function delegated to perform action.
func deleteButton(sender:FavoriteItemTableViewCell){
//How should I delete. How can I get index path here
}
}
Q. What should I write in the deleteButton function ? I am unable to get the indexPath here so what should I do instead. I already have another button in cell and the delegation is working fine.
you can get indexPath using table view point like this
let buttonPosition : CGPoint = sender.convert(sender.bounds.origin, to: tableview)
let indexPath = tableview.indexPathForRow(at: buttonPosition)
Related
I'm trying to make a button do something in another view controller. I made a delegate, added a function with a requirement of having an indexPath so I could use it to delete items in an array, but when I make a variable indexPath equal to IndexPath.self and try feeding it into the actual IBAction, it spits out the error shown in the title. Here is my code for my first view controller, where the IBAction and protocol is defined.
import UIKit
protocol ToDoItemCellDelegate: AnyObject {
func didTapX(with indexPath: IndexPath)
}
class ToDoItemCell: UITableViewCell {
weak var delegate: ToDoItemCellDelegate?
static let identifier = "ToDoItemCell"
static func nib() -> UINib {
return UINib(nibName: "ToDoItemCell", bundle: nil)
}
#IBOutlet var xButton: UIButton!
private var indexPath = IndexPath.self
#IBAction func didTapX(_ sender: UIButton) {
delegate?.didTapX(with: indexPath)
}
override func awakeFromNib() {
super.awakeFromNib()
}
}
You have mistaken type and entity. Your delegate expects an entity and your var only provides a type. You stated in your comment that you do not need to provide any meaningfull value here so you have multiple possibilities:
Remove the argument from the delegate:
protocol ToDoItemCellDelegate: AnyObject {
func didTapX()
}
or create a default value while calling the delegate and remove the property:
#IBAction func didTapX(_ sender: UIButton) {
delegate?.didTapX(with: IndexPath(item: 0, section: 0))
}
or assign a defalut to the property and use it while calling the delegate:
private var indexPath = IndexPath(item: 0, section: 0)
I have a UIView which displays some information such as a user's Name and more, including a list of objects that all get pulled from my database. This works fine.
However, I now have a ViewController that gets presented on top of the current ViewController. In this presented ViewController, I am adding Data to my Database. When dismissing that view, I want the original ViewController to update all of its content to be up to date.
Right now, all my views are getting layedout in ViewDidLoad, meaning that they only really get loaded once and don't reload later on. I have managed to update Layout by calling self.view.layoutIfNeeded(), but if I understand correctly, this only updates constraint. Of course, I could call a new init of my original view controller. This would make it reload, but I would like to avoid that.
Another Idea I had was to set up all my content in the ViewWillAppear, which should maybe then update anytime my view controller is about to be visible. However, I don't know how to go about doing this. Can I just move all my setup code to viewWillAppear? Does this have any disadvantages?
TLDR: Is there a way to update a stackview with new elements without having to reload the full ViewController over ViewWillAppear?
The UITableView element works very smoothly with database data. If you fetch the data from your database inside viewDidLoad in your first view controller, and store it in an array, the UITableView (if you set up its dataSource correctly) will automatically populate the table with the new values from the second view controller. With this method, there is no need to use ViewWillAppear at all.
It sounds like as of now, you're using Views (inside a VStack)? to display individual objects from the database. If you want to keep whatever custom style/layout you're using with your views, this can be done by defining a custom subclass of UITableViewCell and selecting the "Also create XIB file" option. The XIB file lets you customize how the cells in your UITableView look.
Here is a simple example to show the database values in the first view controller automatically updating. I didn't include the custom XIB file (these are all default UITableViewCells), to keep it streamlined.
FIRST VIEW CONTROLLER
import UIKit
import CoreData
class ViewController: UIViewController {
#IBOutlet weak var dataTable: UITableView!
var tableRows: [DataItem] = []
func loadData() {
let request: NSFetchRequest<DataItem> = DataItem.fetchRequest()
do {
tableRows = try Global_Context.fetch(request)
} catch {
print("Error loading data: \(error)")
}
}
override func viewDidLoad() {
super.viewDidLoad()
dataTable.dataSource = self
loadData()
}
#IBAction func goForward(_ sender: UIButton) {
self.performSegue(withIdentifier: "toSecond", sender: self)
}
}
extension ViewController: UITableViewDataSource {
func tableView(_ tableView: UITableView, numberOfRowsInSection section: Int) -> Int {
return tableRows.count
}
func tableView(_ tableView: UITableView, cellForRowAt indexPath: IndexPath) -> UITableViewCell {
let cell = tableView.dequeueReusableCell(withIdentifier: "dataTableCell", for: indexPath)
cell.textLabel?.text = tableRows[indexPath.row].name
return cell
}
}
let Global_Context = (UIApplication.shared.delegate as! AppDelegate).persistentContainer.viewContext
func saveContext () {
if Global_Context.hasChanges {
do {
try Global_Context.save()
} catch {
let nserror = error as NSError
print("Error saving database context: \(nserror), \(nserror.userInfo)")
}
}
}
SECOND VIEW CONTROLLER:
import UIKit
import CoreData
class AddViewController: UIViewController {
#IBOutlet weak var itemEntry: UITextField!
override func viewDidLoad() {
super.viewDidLoad()
itemEntry.delegate = self
}
#IBAction func addNewItem(_ sender: UIButton) {
let newDataItem = DataItem(context: Global_Context)
newDataItem.name = itemEntry.text
saveContext()
}
#IBAction func goBack(_ sender: UIButton) {
self.performSegue(withIdentifier: "toFirst", sender: self)
}
}
extension AddViewController: UITextFieldDelegate {
func textFieldShouldReturn(_ textField: UITextField) -> Bool {
textField.endEditing(true)
return true
}
}
Main.storyboard:
Once you set up your view controller as a UITableViewDataSource (as in the example code), the table view should make things simpler by eliminating any need to manually manage individual Views.
Is this the functionality you were looking for? (Note about the example: it was set up in Xcode with "Use Core Data" enabled.)
Here is a link to the official documentation:
https://developer.apple.com/documentation/uikit/uitableview
I have been searching through many posts on SO but couldn't find an answer to this one.
I have a Table view listing various items. Each cell in the table view has a button that swaps an image around when clicked on, effectively working as an "on" or "off" button to show a user which items in the list they have selected. I have a variable inside my custom Cell Prototype class which stores a value of true or false which is updated every time the button is clicked on.
There is a "Done" button in the Table View that when tapped on calls an unwind Segue to go back to the first View Controller.
When the user taps on the Enter Table View button (on the first View Controller) to display the Table the buttons all go back to their default state, am guessing because each time the segue to the Table View Screen happens it creates a new instance of the Table to be displayed.
What I'm trying to achieve is that the state of the button (either on or off) is retained when going back into the Table screen. I've tried for a while sending an Integer value back from the TableCell Class (using a delegate) to the first View controller and then passing that value back into the Table View controller when the forward segue is called in order to have a "retained from the previous state value" that can be compared against when the cells are created to indicate if a button had been clicked or not. Couldn't get it to work though to save the state of the buttons. The list of Items in the Table will also change depending on what a user adds.
Some Screen shots and the code are below. The code hasn't got the delegate i was trying included (as it didn't work) but if its needed I will edit the post to include it. Any help would be hugely appreciated. Many Thanks!!
Code I have so far is:
//Main View Controller//
class ViewController: UIViewController {
override func viewDidLoad() {
super.viewDidLoad()
}
//segue to the Table View Screen
override func prepare(for segue: UIStoryboardSegue, sender: Any?) {
if segue.identifier == "EnterTableView" {
let newTableView = segue.destination as! TableViewController
}
}
// Unwind Segue Called on Exit From Table View
#IBAction func unwindToMainViewController (_segue:UIStoryboardSegue) {
}
}
// Table View Controller //
class TableViewController: UITableViewController {
var dataArray = ["A", "B", "C", "D"]
override func viewDidLoad() {
super.viewDidLoad()
}
// MARK: - Table view data source
override func numberOfSections(in tableView: UITableView) -> Int {
//create one section for table
return 1
}
override func tableView(_ tableView: UITableView, numberOfRowsInSection section: Int) -> Int {
//create number of rows based on the number of items in the dataArray set above
return dataArray.count
}
// an array that will contain all the cells
var cellArray = [UITableViewCell] ()
override func tableView(_ tableView: UITableView, cellForRowAt indexPath: IndexPath) -> UITableViewCell {
//create a new cell based on the cell class "TableViewCell"
let cell = tableView.dequeueReusableCell(withIdentifier: "TableViewCell", for: indexPath) as? TableViewCell
// variable to contain a single element from the dataArray - updates every time a new cell is created
let dataArrayForCells = dataArray [indexPath.row]
//set cell label text to show the value from the dataArrayForCells
cell!.label.text = dataArrayForCells
cellArray.append(cell!)
return cell!
}
// Table Cell Class//
class TableViewCell: UITableViewCell {
#IBOutlet weak var label: UILabel! // label to hold display some text
#IBOutlet weak var buttonImage: UIImageView! //image for button
var buttonClicked = true //variable to contain weather the has been clicked
//if button is tapped on run the below
#IBAction func aButton(_ sender: Any) {
//if button is clicked is true, swap image to red ("on") button, set buttonClicked value to false
if buttonClicked {
buttonImage.image = #imageLiteral(resourceName: "Rec Button Red")
buttonClicked = false
}
// if buttonClicked value is false swap image to grey ("off") button set buttonClicked value back to true
else {
buttonImage.image = #imageLiteral(resourceName: "Rec Button Grey")
buttonClicked = true
}
}
I'm new to coding, so please bear with me. I was following an online tutorial that worked with plists to make a habit list app. I have a table view controller that shows a list of habits and a segue that presents modally a view controller that has text fields to add a habit.
enter image description here
Every time it runs, nothing happens when I click on the "save" and "cancel" buttons. I realize this is a vague question as it doesn't pinpoint to a specific issue, but I am really struggling with fixing this issue and would really appreciate if someone proofreads the code. The app builds and runs with no warnings.
This is the table view controller that shows the habits:
class TableViewController: UITableViewController {
//MARK: Properties
var habits = [Habit]()
//MARK: - Table view data source
override func numberOfSections(in tableView: UITableView) -> Int {
return 1
}
override func tableView(_ tableView: UITableView, numberOfRowsInSection section: Int) -> Int {
return habits.count
}
override func tableView(_ tableView: UITableView, cellForRowAt indexPath: IndexPath) -> UITableViewCell {
// Table view cells are reused and should be dequeued using a cell identifier.
guard let cell = tableView.dequeueReusableCell(withIdentifier: "cell") else {
fatalError("The dequeued cell is not an instance of ViewController.")
}
// Fetches the appropriate habit for the data source layout.
let habit = habits[indexPath.row]
cell.textLabel?.text = habit.mainGoal
cell.detailTextLabel?.text = habit.microGoal
return cell
}
#IBAction func unwindToHabitList(sender: UIStoryboardSegue) {
if let source = sender.source as?ViewController, let habit = source.habit {
//add a new habit
let newIndexPath = IndexPath(row: habits.count, section: 0)
habits.append(habit)
tableView.insertRows(at: [newIndexPath], with: .automatic)
}
}
This is the view controller that adds a habit:
class ViewController: UIViewController, UITextFieldDelegate, UINavigationControllerDelegate {
#IBOutlet weak var saveButton: UIBarButtonItem!
#IBOutlet weak var mainGoalTextField: UITextField!
#IBOutlet weak var microGoalTextField: UITextField!
var habit: Habit?
//method for configuring controller before presenting
override func prepare(for segue: UIStoryboardSegue, sender: Any?) {
super.prepare(for: segue, sender: sender)
//configure this destination view controller only when save button is pressed
guard let button = sender as? UIBarButtonItem, button === saveButton else {
os_log("save button was not pressed, cancelling", log: OSLog.default, type: .debug)
return
}
let mainGoal = mainGoalTextField.text ?? ""
let microGoal = microGoalTextField.text ?? ""
//set the habit to be passed on to tableViewController after the unwind segue
habit = Habit(mainGoal: mainGoal, microGoal: microGoal)
}
#IBAction func cancel(_ sender: UIBarButtonItem) {
// Depending on style of presentation (modal or push presentation), this view controller needs to be dismissed in two different ways.
let isPresentingInAddHabitMode = presentingViewController is UINavigationController
if isPresentingInAddHabitMode {
dismiss(animated: true, completion: nil)
}
else if let owningNavigationController = navigationController{
owningNavigationController.popViewController(animated: true)
}
else {
fatalError("The ViewController is not inside a navigation controller.")
}
}
I appreciate any and all help in advance!
STORYBOARD CONNECTIONS:
TABLEVIEW CONTROLLER CONNECTIONS
ADD HABIT VIEW CONTROLLER CONNECTIONS
I currently have a ViewController with a TableView inside it called SelectedListItemsViewController. This ViewController's TableView is populated by a custom cell class called SelectedListItemsTableViewCell.
I have an array of Realm Model Objects called selectedListItems, each of which has several properties. The SelectedListItemsTableViewCell populates the TableView with the listItem property of that indexPath.row's object, and each row has a UIStepper with a UILabel next to it that (as of now) shows UIStepper.value for each row. Ideally, the label will reflect the listItemWeight property of each row, and change it when incrementing or decrementing that row.
This is my custom cell:
class SelectedListItemsTableViewCell: UITableViewCell {
#IBOutlet var selectedListItemLabel: UILabel!
#IBOutlet weak var listItemWeightLabel: UILabel!
#IBOutlet weak var stepperControl: UIStepper!
#IBAction func stepperValueChanged(sender: UIStepper) {
listItemWeightLabel.text = Int(sender.value).description
}
}
And in my ViewController's cellForRowAtIndexPath, I've configured the cell like so:
// Configure the cell...
cell.selectedListItemLabel.text = selectedListItems[indexPath.row].listItem
cell.listItemWeightLabel.text = "\(selectedListItems[indexPath.row].listItemWeight)"
Which perfectly loads the listItem property, and the listItemWeight property shows up correctly, but as soon as I increment or decrement on the UIStepper it gets messed up.
How do I properly link my UILabel and UIStepper to the [indexPath.row].listItemWeight?
In the same method that gets called when your stepper updates, update your listItem. However, since this item is stored in your Realm database, you will have to get an instance of your Realm database and write the change to the database.
You can do this by having your TableViewCell hold on to an instance of the listItem. Your new TableViewCell class will look something like this:
class SelectedListItemsTableViewCell: UITableViewCell {
#IBOutlet var selectedListItemLabel: UILabel!
#IBOutlet weak var listItemWeightLabel: UILabel!
#IBOutlet weak var stepperControl: UIStepper!
var listItem: Item?
#IBAction func stepperValueChanged(sender: UIStepper) {
listItemWeightLabel.text = Int(sender.value).description
if let listItem = listItem {
let realm = try! Realm
try! realm.write {
listItem.listItemWeight = Int(sender.value) ?? 0
}
}
}
}
The above answer was helpful in leading me to the actual solution of my issue, but if anyone in the future is curious - I ended up using a closure.
In my custom cell class, I did
#IBAction func stepperValueChanged(sender: UIStepper) {
selectedListItemLabel.text = Int(sender.value).description
tapped?(self)
}
And in my view controller, I did
func tableView(tableView: UITableView, cellForRowAtIndexPath indexPath: NSIndexPath) -> UITableViewCell {
let cell = tableView.dequeueReusableCellWithIdentifier("Cell", forIndexPath: indexPath) as! SelectedListItemsTableViewCell
cell.stepperControl.value = selectedListItems[indexPath.row].listItemWeight
// Configure the cell...
cell.tapped = { (selectedCell) -> Void in
selectedListItems[indexPath.row].listItemWeight = cell.stepperControl.value
}
Which allowed me to access each cell's UIStepper in the view controller file.
It helped to read flashadvanced's Option 2 answer in this thread.