Set UITableView rows as selected if contained in an array - swift

Question

I have data stored in a realm database. I retrieve the information from the database and place it in an array. I then search through the array and set the cell to selected if it is contained in the array.
func tableView(tableView: UITableView, cellForRowAtIndexPath indexPath: NSIndexPath) -> UITableViewCell {
let cell:SubjectsTableViewCell = tableView.dequeueReusableCellWithIdentifier("Cell") as! SubjectsTableViewCell
var subject: Subjects!
subject = Subjects[Int(indexPath.row)]
cell.subject.text = subject.subjectTitle
if chosenSubjects.contains(subject.subjectTitle) {
cell.selected = true
cell.accessoryType = .Checkmark
tableView.selectRowAtIndexPath(indexPath, animated: false, scrollPosition: UITableViewScrollPosition.None)
cell.highlighted = true
} else {
tableView.deselectRowAtIndexPath(indexPath, animated: false)
}
return cell
}
Unfortunately, the above code is giving me some strange results. Sometimes the cells are highlighted and display a checkmark, sometimes the first cell in the table is unhighlighted, but displays a checkmark. Sometimes I have to press the cell twice to deselect. Note, I have also set the didSelectRowAtIndexPath and didDeselectRowAtIndexPath as follows:
func tableView(tableView: UITableView, didSelectRowAtIndexPath indexPath: NSIndexPath) {
// Get the row data for the selected row
self.tableView.allowsMultipleSelection = true
let cell:SubjectsTableViewCell = tableView.cellForRowAtIndexPath(indexPath) as! SubjectsTableViewCell
cell.accessoryType = .Checkmark
}
func tableView(tableView: UITableView, didDeselectRowAtIndexPath indexPath: NSIndexPath) {
// Get the row data for the selected row
self.tableView.allowsMultipleSelection = true
let cell:SubjectsTableViewCell = tableView.cellForRowAtIndexPath(indexPath) as! SubjectsTableViewCell
cell.accessoryType = .None
}

Answer 1

I believe that this can occur because you are reusing cells with your line
let cell:SubjectsTableViewCell = tableView.dequeueReusableCellWithIdentifier("Cell") as! SubjectsTableViewCell
Instead, try doing something like this:
func tableView(tableView: UITableView, cellForRowAtIndexPath indexPath: NSIndexPath) -> UITableViewCell {
let cell:SubjectsTableViewCell = tableView.dequeueReusableCellWithIdentifier("Cell") as! SubjectsTableViewCell
var subject: Subjects!
subject = Subjects[Int(indexPath.row)]
cell.subject.text = subject.subjectTitle
if chosenSubjects.contains(subject.subjectTitle) {
cell.selected = true
cell.accessoryType = .Checkmark
tableView.selectRowAtIndexPath(indexPath, animated: false, scrollPosition: UITableViewScrollPosition.None)
cell.highlighted = true
} else {
cell.selected = false
cell.accessoryType = .None
cell.highlighted = false
tableView.deselectRowAtIndexPath(indexPath, animated: false)
}
return cell
}
Hope this helps; let me know if it doesn't!
Edit:
I just noticed that within your select and deselect tableview functions, you don't actually update your chosenSubjects array for the given row. You need to update this before you call cellForRowAtIndexPath; otherwise, the if condition (in your cellForRowAtIndexPath) will fail - thus leading to the weird behaviour!
Try this:
func tableView(tableView: UITableView, didSelectRowAtIndexPath indexPath: NSIndexPath) {
// Get the row data for the selected row
self.tableView.allowsMultipleSelection = true
var subject: Subjects! = Subjects[Int(indexPath.row)]
chosenSubjects.addObject(subject.subjectTitle)
let cell:SubjectsTableViewCell = tableView.cellForRowAtIndexPath(indexPath) as! SubjectsTableViewCell
cell.accessoryType = .Checkmark
}
and this:
func tableView(tableView: UITableView, didDeselectRowAtIndexPath indexPath: NSIndexPath) {
// Get the row data for the selected row
self.tableView.allowsMultipleSelection = true
var subject: Subjects! = Subjects[Int(indexPath.row)]
chosenSubjects = chosenSubjects.filter() { $0 != subject.subjectTitle }
let cell:SubjectsTableViewCell = tableView.cellForRowAtIndexPath(indexPath) as! SubjectsTableViewCell
cell.accessoryType = .None
}

Answer 2

var userCLient = string is an empty string array declare..
func tableView(_ tableView: UITableView, didSelectRowAt indexPath: IndexPath) {
let selectedRow:UITableViewCell = tableView.cellForRow(at: indexPath)!
if selectedRow.accessoryType == UITableViewCellAccessoryType.none{
selectedRow.accessoryType = UITableViewCellAccessoryType.checkmark
selectedRow.tintColor = UIColor.green
var dict = arrRes[(indexPath as NSIndexPath).row]
let EmpID = dict["user_id"] as? Int
self.userCLient.append(String(describing: EmpID!))
print("Employee:\(self.userCLient)")
}
else{
selectedRow.accessoryType = UITableViewCellAccessoryType.none
var dict = arrRes[(indexPath as NSIndexPath).row]
let EmpID = dict["user_id"] as? Int
if let index = self.userCLient.index(of: String(describing: EmpID!)) {
self.userCLient.remove(at: index)
}
print("Employee:\(self.userCLient)")
}
}