UITableViewDiffableDataSource is not calling tableView(_:commit:forRowAt:) - ios

There is a UITableView that uses UITableViewDiffableDataSource. I subclassed UITableViewDiffableDataSource to add canEditRowAt. This correctly shows the swipeable delete action when gesturing the row. However, clicking the delete option does not call tableView(_:commit:forRowAt:). I have read that you have to use tableView(_:trailingSwipeActionsConfigurationForRowAt:indexPath:) because the other function is not supported. I wanted to confirm that was true. If we subclass tableView(_:commit:forRowAt:) as well, we need a clean way to call a function on the original View Controller.
// MyViewController
override func tableView(_ tableView: UITableView, commit editingStyle: UITableViewCell.EditingStyle, forRowAt indexPath: IndexPath) {
if editingStyle == .delete {
// Delete cell
}
}
// Subclass DiffableDataSource used in MyViewController
final class CustomDiffableDatasource: UITableViewDiffableDataSource<MyViewController.Section, MyViewController.Item> {
override func tableView(_ tableView: UITableView, canEditRowAt indexPath: IndexPath) -> Bool {
guard let item = itemIdentifier(for: indexPath) else {
return false
}
return item.isEditable
}
}

Here is the custom trailingSwipeActionsConfigurationForRowAtfunc looks like for adding a delete swipe. I saw this in another StackOverflow question that referenced a blog post.
override func tableView(_ tableView: UITableView, trailingSwipeActionsConfigurationForRowAt indexPath: IndexPath) -> UISwipeActionsConfiguration? {
guard self.dataSource?.tableView(tableView, canEditRowAt: indexPath) == true else {
return nil
}
let delete = UIContextualAction(style: .destructive, title: "Delete") { [weak self] action, view, success in
self?.remove(at: indexPath)
success(true)
}
let swipeActionConfig = UISwipeActionsConfiguration(actions: [delete])
swipeActionConfig.performsFirstActionWithFullSwipe = false
return swipeActionConfig
}

Related

Disable delete option for specific UITableViewCell in a UITableView

for UITableViews I have added three difference cells
How to Enable delete option for specific cell
func tableView(_ tableView: UITableView, commit editingStyle: UITableViewCell.EditingStyle, forRowAt indexPath: IndexPath) {
switch dataSource[indexpath.section].menu {
case "Attachment":
if editingStyle == AttachmentTableViewCell.EditingStyle.delete {
attachmentList.remove(at: indexPath.row)
tableView.deleteRows(at: [indexPath], with: UITableView.RowAnimation.automatic)
}
break
default:
break
}
}
In this case it's shows Delete option for other cell too.
How to stop showing the Delete option on swipe to other UITableViewCell.
Implement tableView(_:editingStyleForRowAt:) and return none for the index paths which should not show the delete option.
This worked for me.
Overriding this func from UITableViewController
or implementing it UITableViewDelegate
override func tableView(_ tableView: UITableView, leadingSwipeActionsConfigurationForRowAt indexPath: IndexPath) -> UISwipeActionsConfiguration?
The indexpaths were you want an action return a UISwipeActionsConfiguration else return nil.
like this
override func tableView(_ tableView: UITableView, leadingSwipeActionsConfigurationForRowAt indexPath: IndexPath) -> UISwipeActionsConfiguration? {
// return nil on specific rows
guard indexPath.row != 1 else {
return nil
}
let contexualAction = UIContextualAction(style: .normal, title: "Action") { _, _, _ in
// Do Action
}
let swipeAction = UISwipeActionsConfiguration(actions: [contexualAction])
return swipeAction
}

trailingSwipeActionsConfigurationForRowAt not work in stability

I am trying to make swipe-able table view cell for iOS 11 and above and trying to use the trailingSwipeActionsConfigurationForRowAt but it works on iPad and doesn't work on iPhone. It is not called in iPhone.
Surprisingly if I try to swipe the cell more then 10 or 20 times it sometimes works for once.
Here is my controller's table view extension
import UIKit
extension CustomViewController: UITableViewDelegate, UITableViewDataSource {
func initTableView() {
tableView.register(cell: SingleLineListItemViewCell.self)
tableView.delegate = self
tableView.dataSource = self
tableView.estimatedRowHeight = 64
tableView.rowHeight = UITableView.automaticDimension
tableView.backgroundColor = .green
tableView.isEditing = false
}
func tableView(_ tableView: UITableView, numberOfRowsInSection section: Int) -> Int {
return 3
}
func tableView(_ tableView: UITableView, cellForRowAt indexPath: IndexPath) -> UITableViewCell {
let model = SingleLineListItemViewModel(title: "coko")
let cell = tableView.dequeueReusableCell(withIdentifier: SingleLineListItemViewCell.reuseIdentifier) as? SingleLineListItemViewCell
cell?.model = model
cell?.isFirst = indexPath.row == 0
cell?.isLast = indexPath.row == 2
return cell!
}
func tableView(_ tableView: UITableView, viewForHeaderInSection section: Int) -> UIView? {
return nil
}
func tableView(_ tableView: UITableView, heightForHeaderInSection section: Int) -> CGFloat {
return 0
}
func tableView(_ tableView: UITableView, heightForRowAt indexPath: IndexPath) -> CGFloat {
return 100
}
func tableView(_ tableView: UITableView, estimatedHeightForRowAt indexPath: IndexPath) -> CGFloat {
return 64.0
}
func tableView(_ tableView: UITableView, didSelectRowAt indexPath: IndexPath) {
tableView.deselectRow(at: indexPath, animated: true)
print("didSelectRowAt....")
router?.routeToTransfer()
}
func tableView(_ tableView: UITableView, canEditRowAt indexPath: IndexPath) -> Bool {
return true
}
#available(iOS 11.0, *)
func tableView(_ tableView: UITableView, leadingSwipeActionsConfigurationForRowAt indexPath: IndexPath) -> UISwipeActionsConfiguration? {
return nil
}
func tableView(_ tableView: UITableView, commit editingStyle: UITableViewCell.EditingStyle, forRowAt indexPath: IndexPath) {
// Action here
// In case of delete, you can simply do:
if editingStyle == .delete {
//Remove item at relative position from datasource array
//Reload tableview at the respective indexpath
}
}
#available(iOS 11.0, *)
func tableView(_ tableView: UITableView, trailingSwipeActionsConfigurationForRowAt indexPath: IndexPath) -> UISwipeActionsConfiguration? {
let deleteAction = UIContextualAction(style: .destructive, title: "Delete") { _, _, _ in
//YOUR_CODE_HERE
}
deleteAction.backgroundColor = .red
let configuration = UISwipeActionsConfiguration(actions: [deleteAction])
configuration.performsFirstActionWithFullSwipe = false
return configuration
}
}
Any help would be much appreciated.
The only obvious thing wrong with this is that you're not calling the completion handler. According to the API documentation it is necessary to call the completion handler to indicate whether the operation was successful. What it actually does I have no idea...
func tableView(_ tableView: UITableView, trailingSwipeActionsConfigurationForRowAt indexPath: IndexPath) -> UISwipeActionsConfiguration? {
let deleteAction = UIContextualAction(style: .destructive, title: "Delete") { _, _, completionHandler in
//YOUR_CODE_HERE
completionHandler(true)
}
deleteAction.backgroundColor = .red
let configuration = UISwipeActionsConfiguration(actions: [deleteAction])
configuration.performsFirstActionWithFullSwipe = false
return configuration
}
If this doesn't make any difference, do you have any other gesture recognisers that could be conflicting with the swipe action?
you can try this one
func tableView(_ tableView: UITableView, canEditRowAt indexPath: IndexPath) -> Bool {
return true
}
func tableView(_ tableView: UITableView, titleForDeleteConfirmationButtonForRowAt indexPath: IndexPath) -> String? {
return "Delete"
}
// this method handles row deletion
func tableView(_ tableView: UITableView, commit editingStyle: UITableViewCell.EditingStyle, forRowAt indexPath: IndexPath) {
if editingStyle == .delete {
// remove the item from the data model
// delete the table view row
tableView.deleteRows(at: [indexPath], with: .fade)
} else if editingStyle == .insert {
// Not used in our example, but if you were adding a new row, this is where you would do it.
}
}
func tableView(_ tableView: UITableView, trailingSwipeActionsConfigurationForRowAt indexPath: IndexPath) -> UISwipeActionsConfiguration? {
let action = UIContextualAction(
style: .normal,
title: "Delete",
handler: { (action, view, completion) in
//do what you want here
completion(true)
})
action.backgroundColor = .red
let configuration = UISwipeActionsConfiguration(actions: [action])
configuration.performsFirstActionWithFullSwipe = false
return configuration
}
Here is are actions defined as well (point 1 and 2);
func tableView(_ tableView: UITableView, trailingSwipeActionsConfigurationForRowAt indexPath: IndexPath) -> UISwipeActionsConfiguration? {
let deleteAction = UIContextualAction(style: .destructive, title: "") { _, _, completionHandler in
// 1. remove object from your array
scannedItems.remove(at: indexPath.row)
// 2. reload the table, otherwise you get an index out of bounds crash
self.tableView.reloadData()
completionHandler(true)
}
deleteAction.backgroundColor = .systemOrange
deleteAction.image = UIImage(named: "trash")
let configuration = UISwipeActionsConfiguration(actions: [deleteAction])
configuration.performsFirstActionWithFullSwipe = true
return configuration
}

UITableView Swipe to Delete Button Not Showing Up

I have done this hundreds of time but currently, I have no idea why the Delete button is not showing up when I swipe from right to left.
override func tableView(_ tableView: UITableView, commit editingStyle: UITableViewCell.EditingStyle, forRowAt indexPath: IndexPath) {
if editingStyle == .delete {
}
}
I have implemented the commit tableView delegate which makes the delete button appears automatically. But for some reason it does not do anything. Delete button never shows up.
Every time I swipe the segue gets fired and it takes me to a separate screen.
override func prepare(for segue: UIStoryboardSegue, sender: Any?) {
if segue.identifier == "showOrderDetails" {
guard let indexPath = tableView.indexPathForSelectedRow else {
return
}
let order = self.orders[indexPath.row]
let placeOrderTVC = segue.destination as! PlaceOrderTableViewController
placeOrderTVC.order = order
}
}
I've had this before, you need to implement the editActionsForRowAt delegate method. It seems sometimes this is required and other times it isn't.
func tableView(_ tableView: UITableView, editActionsForRowAt indexPath: IndexPath) -> [UITableViewRowAction]? {
let result = UITableViewRowAction(style: .destructive, title: "Delete") {
(_, indexPath) in
//Delete from your data structure here
}
return [result]
}
The canEditRowAt datasource method is defaulted to true so I've never been required to implement that method.
Try this code, you need to write canEditRowAt delegate also
override func tableView(_ tableView: UITableView, canEditRowAt indexPath: IndexPath) -> Bool {
return true
}
override func tableView(_ tableView: UITableView, commit editingStyle: UITableViewCellEditingStyle, forRowAt indexPath: IndexPath) {
if (editingStyle == UITableViewCellEditingStyle.delete) {
// handle delete
}
}

UITableVIew swipe trailingSwipeActionsConfigurationForRowAt not working

New iOS 11 UITableView Swipe action not getting called. The delegate and datasource are working fine for the table.
I am not able to swipe and see the menu items.
Below is my code for the same.
func tableView(_ tableView: UITableView, leadingSwipeActionsConfigurationForRowAt indexPath: IndexPath) -> UISwipeActionsConfiguration? {
let contextItem = UIContextualAction(style: .normal, title: "Leading & .normal") { (contextualAction, view, boolValue) in
print("Leading Action style .normal")
}
let swipeActions = UISwipeActionsConfiguration(actions: [contextItem])
return swipeActions
}
func tableView(_ tableView: UITableView, trailingSwipeActionsConfigurationForRowAt indexPath: IndexPath) -> UISwipeActionsConfiguration? {
let contextItem = UIContextualAction(style: .destructive, title: "Trailing & .destructive") { (contextualAction, view, boolValue) in
print("Trailing Action style .destructive")
}
let swipeActions = UISwipeActionsConfiguration(actions: [contextItem])
return swipeActions
}
I tried to call below and its working fine.
func tableView(_ tableView: UITableView, commit editingStyle: UITableViewCellEditingStyle, forRowAt indexPath: IndexPath) {
if editingStyle == .delete {
}
}
Any hint in right direction is highly appreciated.
You need to pass true to UIContextualAction in the closure boolValue(true). Otherwise the handler won't allow the action.
func tableView(_ tableView: UITableView, leadingSwipeActionsConfigurationForRowAt indexPath: IndexPath) -> UISwipeActionsConfiguration? {
let contextItem = UIContextualAction(style: .normal, title: "Leading & .normal") { (contextualAction, view, boolValue) in
boolValue(true) // pass true if you want the handler to allow the action
print("Leading Action style .normal")
}
let swipeActions = UISwipeActionsConfiguration(actions: [contextItem])
return swipeActions
}
For those who uses UITableViewDiffableDataSource you need to subclass it and override its canEditRowAt method.
public override func tableView(_ tableView: UITableView, canEditRowAt indexPath: IndexPath) -> Bool {
true
}
Code looks good, but you are missing probably missing the following the "UITableViewDelegate" in the Class declaration and also the "TableView.delegate = self" in the viewdidload() section. So it should look like:
class ViewController: UIViewController, UITableViewDataSource, UITableViewDelegate {
override func viewDidLoad() {
super.viewDidLoad()
tableView.dataSource = self
tableView.delegate = self
}
}

Change the text of the cell delete button

i'm trying to change the delete button of a cell.
I have 2 functions :
override func tableView(_ tableView: UITableView, editActionsForRowAt indexPath: IndexPath) -> [UITableViewRowAction]? {
let titleBtn = UITableViewRowAction(style: UITableViewRowActionStyle.default, title: "Supprimer") { (action , indexPath ) -> Void in
self.isEditing = false
//ackAction.backgroundColor = UIColor.orange
}
return [titleBtn]
}
override func tableView(_ tableView: UITableView, canEditRowAt indexPath: IndexPath) -> Bool {
return true
}
But, when I run my app, the text of the button is changed but the delete doesn't work (i can't delete data from my array and the row of my tableview). Before to add this functions all worked perfectly.
A detail: in the canEditRowAt function, I tried to return false too...
Thanks by advance
if you want to change the text of the delete button, conform this method in the UITableViewDelegate:
func tableView(_ tableView: UITableView, titleForDeleteConfirmationButtonForRowAt indexPath: IndexPath) -> String?
{
return "Your new title"
}
To delete the item from the array conform this method
func tableView(_ tableView: UITableView, commit editingStyle: UITableViewCellEditingStyle, forRowAt indexPath: IndexPath)
{
if (editingStyle == UITableViewCellEditingStyle.delete)
{
yourDataSourceArray.remove(at: indexPath.row)
yourTableView.reloadData()
}
}
You can either use default delete action and change its title like this.
func tableView(_ tableView: UITableView, titleForDeleteConfirmationButtonForRowAt indexPath: IndexPath) -> String?
{
return "MyAction"
}
or you can create your own action buttons like this.
func tableView(_ tableView: UITableView, canEditRowAt indexPath: IndexPath) -> Bool {
return true
}
func tableView(_ tableView: UITableView, editActionsForRowAt indexPath: IndexPath) -> [UITableViewRowAction]? {
let deleteAction = UITableViewRowAction(style: .default, title: "Delete") {action in
//handle delete
}
let editAction = UITableViewRowAction(style: .normal, title: "Edit") {action in
//handle edit
}
return [deleteAction, editAction]
}

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