How to restrict deleting rows in TableView only to certain users? - ios

My problem is as follows. I created an app that allows users to add posts to rows in TableViewController. It also lets them delete only their posts with UITableViewCellEditingStyle by checking if the current user has the same id as the id of the user who created the post. Unfortunately, this way of editing the cells also allows to try to delete others users posts. I would like to make that the delete button only appears when users swipe their posts. I attach an image of the button I have been talking about.

You can do something like this:
If you don't have a custom class for UITableViewCell:
override func tableView(tableView: UITableView, editingStyleForRowAtIndexPath indexPath: NSIndexPath) -> UITableViewCellEditingStyle {
if owner[indexPath.row] == me {
return .Delete
}
else {
return .None
}
}
Or if you have a custom class for UITableViewCell then this:
override func tableView(tableView: UITableView, editingStyleForRowAtIndexPath indexPath: NSIndexPath) -> UITableViewCellEditingStyle {
if (tableView.cellForRowAtIndexPath(indexPath) as! YourTableViewCell).owner == me {
return .Delete
}
else {
return .None
}
}

Simply do the check for matching user ids in the tableview's delegate editingStyleForRowAtIndexPath, returning UITableViewCellEditingStyle.None if the user is invalid.
Reference for editingStyleForRowAtIndexPath

You can also try this, remember to set the default editingStyle for cell
func tableView(tableView: UITableView, canEditRowAtIndexPath indexPath: NSIndexPath) -> Bool {
return owner[indexPath.row] == me
}

Related

tableView.addGestureRecognizer for one section of the tableViewController

I'm new to iOS, swift. I have two sections in my tableView. I want to be able to do a longPressGesture on the second section, and not the first, enabling the user to reorder tableview cells in the second section. How would I do that in swift? Would anyone kindly provide a simple sample code in Swift?
Thanks for your help, much appreciated!
If you just want to reorder move the cell for the particular you may add some button/action to enable/disable reorder , there is delegate which you can use
Your code can be like this:
//enable editing in the tableview to true when you want to enable reorder in your case may on the UILongPressGestureRecognizer action
//In viewDidLoad()
tblView.editing = true//set it to false to complete the reorder
The delegate methods can be use like this:
func tableView(tableView: UITableView, editingStyleForRowAtIndexPath indexPath: NSIndexPath) -> UITableViewCellEditingStyle {
return UITableViewCellEditingStyle.None
}
func tableView(tableView: UITableView, moveRowAtIndexPath fromIndexPath: NSIndexPath, toIndexPath: NSIndexPath) {
//get the reorder change in the path, you can do operation on the array
let itemToMove:String = arrData[fromIndexPath.row]//get the old path of item
arrData.removeAtIndex(fromIndexPath.row)//remove item from old path
arrData.insert(itemToMove, atIndex: toIndexPath.row)//at item at new path in array
}
func tableView(tableView: UITableView, canMoveRowAtIndexPath indexPath: NSIndexPath) -> Bool {
//write code to allow reorder in the particular section/indexpath
if indexPath.section == 0 {
return false
} else {
return true
}
// Return false if you do not want the item to be re-orderable.
}
func tableView(tableView: UITableView, targetIndexPathForMoveFromRowAtIndexPath sourceIndexPath: NSIndexPath, toProposedIndexPath proposedDestinationIndexPath: NSIndexPath) -> NSIndexPath {
//check if the reorder is allow in the particular section/indexpath before the reorder is done, return the old path if you don't want to move at Proposed path
if sourceIndexPath.section != proposedDestinationIndexPath.section {
return sourceIndexPath
} else {
return proposedDestinationIndexPath
}
}
the UILongPressGestureRecognizer can be implemented on the tableview or the tableview cell based on the requirements
let longpress = UILongPressGestureRecognizer(target:self, action:#selector(HomeScreenTableViewController.longPressGestureRecognized))
tblView.addGestureRecognizer(longpress)
func longPressGestureRecognized() {
NSLog("Detected")
tblView.editing = true
}
or in tableview cell with same method as above
let longpress = UILongPressGestureRecognizer(target:self, action:#selector(HomeScreenTableViewController.longPressGestureRecognized))
cell.addGestureRecognizer(longpress)

remove the delete button ⛔️ on table rows in edit mode

I am trying to learn Swift, but there is a problem in my project that drives me nuts.
I have a working list of data in a ViewController fed by parse.com. I managed to implement a swipe-feature that reveals buttons for both deleting and editing. That is working fine. Now I want the user to be able to reorder the cells. So I successfully implemented a button to put the table into editing-mode. My 2 problems with that are:
When I enter edit-mode I just want to be able to reorder the cells since editing and deleting is done via swipe (via "tableView(tableView: UITableView, editActionsForRowAtIndexPath indexPath: NSIndexPath)". How can I achive that the user doesn't see the 2 buttons for deleting and editing when in editing-mode and touching the delete-circle that is provided automatically?
Is it possible to remove the delete-circle altogether? Using "UITableViewCellEditingStyle.None" also disables the swipe-functionality.
Thanks in advance!
To avoid the round red delete button that appears when you put set UITableView isEditing to true at the left and does nothing when you click it, the minimum that worked for me was this (Swift 4, iOS 11)
// Avoid the round red delete button on the left of the cell:
func tableView(_ tableView: UITableView, shouldIndentWhileEditingRowAt indexPath: IndexPath) -> Bool {
return false
}
func tableView(_ tableView: UITableView, editingStyleForRowAt indexPath: IndexPath) -> UITableViewCellEditingStyle {
return .none
}
I also have these functions, which probably interact:
func tableView(_ tableView: UITableView, canEditRowAt indexPath: IndexPath) -> Bool {
return savedTempTable.isEditing
}
// Including this function in the delegate enable left-swipe deleting
func tableView(_ tableView: UITableView, commit editingStyle: UITableViewCellEditingStyle, forRowAt indexPath: IndexPath)
{
if editingStyle == .delete {
savedConversions.remove(at: indexPath.row)
}
}
// Including this function enables reordering
func tableView(_ tableView: UITableView, moveRowAt sourceIndexPath: IndexPath,to destinationIndexPath: IndexPath)
{
let elem = savedConversions.remove(at: sourceIndexPath.row)
savedConversions.insert(elem, at: destinationIndexPath.row)
}
override func tableView(_ tableView: UITableView, editingStyleForRowAt indexPath: IndexPath) -> UITableViewCellEditingStyle {
return .none
}
override func tableView(_ tableView: UITableView, shouldIndentWhileEditingRowAt indexPath: IndexPath) -> Bool {
return false
}
Although people can delete a row through swipe the delete-button in editing mode should not be removed. People may not know about the swipe gesture and by removing the delete button (which they already expect in editing mode) the app becomes more difficult to use.
If you really want to remove the delete button then you have to implement the delegate method tableView(_:editingStyleForRowAtIndexPath:). There you can return .None while the screen is in editing mode and .Delete while the screen is not.
To enable reordering you have to implement the data source methods tableView(_:canMoveRowAtIndexPath:) and tableView(_:moveRowAtIndexPath:toIndexPath:).
You follow this way to remove the delete Icon while editing:
-(UITableViewCellEditingStyle)tableView:(UITableView *)tableView editingStyleForRowAtIndexPath:(NSIndexPath *)indexPath{
return UITableViewCellAccessoryNone;
}

using editActionsForRowAtIndexPath to delete a row "UITableView internal bug"

I need to create a action in editActionsForRowAtIndexPath to delete a row in a table. Following some research on the internet I came to this code:
func tableView(tableView: UITableView, editActionsForRowAtIndexPath indexPath: NSIndexPath) -> [UITableViewRowAction]? {
let remove = UITableViewRowAction(style: UITableViewRowActionStyle.Destructive, title: "Remover", handler: { (action: UITableViewRowAction, indexPath: NSIndexPath) -> Void in
self.tableData.removeObjectAtIndex(indexPath.row)
tableView.deleteRowsAtIndexPaths([indexPath], withRowAnimation: .Automatic)
})
return [remove]
}
but now I get this error
UITableView internal bug: unable to generate a new section map with
old section count: 1 and new section count: 0
When you delete a row from UITableView, you need to take care of two things.
First you should call tableView.deleteRowsAtIndexPaths only after you remove the object from the data source already. Because it'll check for the count again and ensure that the resultant data source have one less value.
Now the second thing to remember is that the no. of section can't be 0 after you delete the last row. If you are returning 0 to numberOfSectionsInTableView, return 1 at least on empty row count. Another option is to actually delete the index too when you delete the last row.
You don't need to use 'editActionsForRowAtIndexPath' method unless you implement your own custom accessory view but other wise you can use the standard swipe left gesture to delete rows and the delegate called is commitEditingStyle
override func tableView(tableView: UITableView, commitEditingStyle editingStyle: UITableViewCellEditingStyle, forRowAtIndexPath indexPath: NSIndexPath) {
if editingStyle == .Delete {
tableData.removeObjectAtIndex(indexPath.row)
tableView.deleteRowsAtIndexPaths([indexPath], withRowAnimation: .Automatic)
}
else if editingStyle == .Insert {
//edit cell
}
}
//change the default 'Delete' text
override func tableView(tableView: UITableView, titleForDeleteConfirmationButtonForRowAtIndexPath indexPath: NSIndexPath) -> String? {
return "Show this instead of delete"
}
Do deleteRowsAtIndexPaths or reloadData, but not both.

Create Action For Static Cell Clicked in UITableView

How can I make a static table view to create an action when one of the cells is clicked in Swift?
I have created a static table like a general menu of the app, I can directly create a push segue when one of the cells are clicked. But at the same time when I click to one of the seques, I want the below function to be run. By draging a cell to the UITableView in storyboard the create action option is not appearing.
var goToProfiles = PFObject(className: "goToProfile")
goToProfiles["user"] = PFUser.currentUser()!.username
goToProfiles["goToUser"] = usernameLbl.text
goToProfiles.save()
If you use sections you will also need to query them.
override func tableView(tableView: UITableView,
didSelectRowAtIndexPath indexPath: NSIndexPath) {
print(indexPath.section)
print(indexPath.row)
if indexPath.section == 1 && indexPath.row == 1 {
// do something
}
}
I found the solution with the code below:
override func tableView(tableView: UITableView,
didSelectRowAtIndexPath indexPath: NSIndexPath) {
if indexPath.row == 1 {
//here you can enter the action you want to start when cell 1 is clicked
}
}
For swift 3 compatibility:
func tableView(_ tableView: UITableView, didSelectRowAt indexPath: IndexPath) {
//Your action here
}

How to enable move but disable delete for some row in UITableView

Some rows in my UITableView needs to delete and move in edit mode, but some just move.
In this method I can enable or disable editing for some rows
override func tableView(tableView: UITableView, canEditRowAtIndexPath indexPath: NSIndexPath) -> Bool{
return true
}
But how to disable delete for some rows with enabled move?
Return .None for editingStyleForRowAtIndexPath:
func tableView(tableView: UITableView, editingStyleForRowAtIndexPath indexPath: NSIndexPath) -> UITableViewCellEditingStyle {
return .None
}
A more complete answer that displays how to remove indentions is here -> Is there any way to hide "-" (Delete) button while editing UITableView

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