Swift: Multiple TableView checkmark - select all rows - ios

Question

It is posible to add a select all option in TableView Multiple checkmarks...?
I have a code ready, and I try to do this function. please help me !
CODE:
struct Area {
let name : String
var isSelected : Bool
init(name : String, isSelected : Bool = false) {
self.name = name
self.isSelected = isSelected
}
}
var areas = [Area(name: "Select all"),Area(name: "a"),Area(name: "b"),Area(name: "c"),Area(name: "d"]
func tableView(_ tableView: UITableView, numberOfRowsInSection section: Int) -> Int
{
return areas.count
}
func tableView(_ tableView: UITableView, cellForRowAt indexPath: IndexPath) -> UITableViewCell{
let cell = tableView.dequeueReusableCell(withIdentifier: "cell", for: indexPath)
let area = areas[indexPath.row]
cell.textLabel?.text = area.name
cell.accessoryType = area.isSelected ? .checkmark : .none
return cell
}
func tableView(_ tableView: UITableView, didSelectRowAt indexPath: IndexPath) {
areas[indexPath.row].isSelected.toggle()
tableView.reloadRows(at: [indexPath], with: .none)
let selectedAreas = areas.filter{$0.isSelected}.map{$0.name}
print(selectedAreas)
}
Thanks.

Answer 1

You have to check if the user selected the first row ("Select all") and update the other rows accordingly:
override func tableView(_ tableView: UITableView, didSelectRowAt indexPath: IndexPath) {
// toggle the selected area
areas[indexPath.row].isSelected.toggle()
// save the new state for later use
let isSelected = areas[indexPath.row].isSelected
if indexPath.row == 0 {
// "Select all" was selected – update all areas
for i in 1..<areas.count {
areas[i].isSelected = isSelected
}
// update UI
tableView.visibleCells.forEach { $0.accessoryType = isSelected ? .checkmark : .none }
} else {
// update UI
tableView.cellForRow(at: indexPath)?.accessoryType = isSelected ? .checkmark : .none
}
tableView.deselectRow(at: indexPath, animated: true)
}
Recommendation
To separate concerns visually you could also use an own table view section for the "Select all" row. In that case some more changes are necessary:
var areas = [
// you do not need an area for "Select all" any longer
Area(name: "a"),
Area(name: "b"),
Area(name: "c"),
Area(name: "d")
]
var allSelected: Bool {
// helper var to see if all areas are currently selected
return areas.filter({!$0.isSelected}).isEmpty
}
override func numberOfSections(in tableView: UITableView) -> Int {
return 2
}
override func tableView(_ tableView: UITableView, titleForHeaderInSection section: Int) -> String? {
switch section {
case 1: return "Areas"
default: return nil
}
}
override func tableView(_ tableView: UITableView, numberOfRowsInSection section: Int) -> Int {
switch section {
case 0: return 1 // select all
case 1: return areas.count
default:
// we should never get here
fatalError()
}
}
override func tableView(_ tableView: UITableView, cellForRowAt indexPath: IndexPath) -> UITableViewCell{
let cell = tableView.dequeueReusableCell(withIdentifier: "cell", for: indexPath)
cell.selectionStyle = .none
if indexPath.section == 0 {
cell.textLabel?.text = "Select all"
cell.accessoryType = allSelected ? .checkmark : .none
} else {
let area = areas[indexPath.row]
cell.textLabel?.text = area.name
cell.accessoryType = area.isSelected ? .checkmark : .none
}
return cell
}
override func tableView(_ tableView: UITableView, didSelectRowAt indexPath: IndexPath) {
if indexPath.section == 0 {
// (de-)select all
let shouldSelect = !allSelected
for i in 0..<areas.count {
areas[i].isSelected = shouldSelect
}
} else {
areas[indexPath.row].isSelected.toggle()
}
tableView.reloadRows(at: tableView.indexPathsForVisibleRows ?? [], with: .automatic)
}

Answer 2

First you need to enable multiple selection for the table view
tableView.allowsMultipleSelection = true
tableView.allowsMultipleSelectionDuringEditing = true
Select all rows
for section in 0..<tableView.numberOfSections {
for row in 0..<tableView.numberOfRows(inSection: section) {
let indexPath = IndexPath(row: row, section: section)
tableView.selectRow(at: indexPath, animated: false, scrollPosition: .none)
}
}
To enable checkmark whenever a row is selected:
func tableView(_ tableView: UITableView, didSelectRowAt indexPath: IndexPath) {
if let cell = tableView.cellForRow(at: indexPath) {
let area = areas[indexPath.row]
area.isSelected = true
cell.accessoryType = .checkmark
}
}
Also remove checkmark when it is deselected:
func tableView(_ tableView: UITableView, didDeselectRowAt indexPath: IndexPath) {
if let cell = tableView.cellForRow(at: indexPath) {
let area = areas[indexPath.row]
area.isSelected = false
cell.accessoryType = .none
}
}
Please vote this answer if it helps. Thanks.

Answer 3

First change your Area to class so it will be reference type
class Area {
let name : String
var isSelected : Bool
init(name : String, isSelected : Bool = false) {
self.name = name
self.isSelected = isSelected
}
}
Now change your didselect logic
func tableView(_ tableView: UITableView, didSelectRowAt indexPath: IndexPath) {
let area = areas[indexPath.row]
area.isSelected.toggle()
if area.name == "Select all"{
areas = areas.map{$0.isSelected = true}
}
tableView.reloadRows(at: [indexPath], with: .none)
let selectedAreas = areas.filter{$0.isSelected}.map{$0.name}
print(selectedAreas)
}

Answer 4

In didSelectRow:
if indexPath.row == 0 { // the first item is the select all button
// find out which areas should be selected
let indicesThatShouldBeSelected = (1..<areas.count).filter { !areas[$0].isSelected }
// update model
indicesThatShouldBeSelected.forEach { areas[$0].isSelected = true }
// update view
tableView.reloadRows(at: indicesThatShouldBeSelected.map { IndexPath(section: 0, row: $0) }, with: .none)
}
You could also just do tableView.reloadData(), which reloads the whole table view instead of just the rows that needs reloading.

Answer 5

If the selectAll row is at index 0 check the row, then set all isSelected members to true and reload the entire table
func tableView(_ tableView: UITableView, didSelectRowAt indexPath: IndexPath) {
if indexPath.row == 0 {
areas.indices.forEach{areas[$0].isSelected = true}
tableView.reloadData()
} else {
areas[indexPath.row].isSelected.toggle()
tableView.reloadRows(at: [indexPath], with: .none)
}
let selectedAreas = areas.filter{$0.isSelected}.map{$0.name}
print(selectedAreas)
}
And if you want to exclude the first item to be selected drop the first index
areas.indices.dropFirst().forEach{areas[$0].isSelected = true}