Making table view section expand swift - ios

Question

I am following this tutorial for expanding and collapsing my table view section. As this demo is done in swift 2.2 I have made all the changes according to swift 3.0 . I am stuck at the below function at if condition(currentSectionCells[row]["isVisible"]) which gives me error as "Type 'NSFastEnumerationIterator.Element' (aka 'Any' has no subscript members)'".
func getIndicesOfVisibleRows() {
visibleRowsPerSection.removeAll()
for currentSectionCells in cellDescriptors {
var visibleRows = [Int]()
for row in 0...((currentSectionCells as! [[String: AnyObject]]).count - 1) {
if currentSectionCells[row]["isVisible"] as! Bool == true {
visibleRows.append(row)
}
}
visibleRowsPerSection.append(visibleRows)
}
}
I have tried type casting it as below
func getIndicesOfVisibleRows() {
visibleRowsPerSection.removeAll()
for currentSectionCells in cellDescriptors {
var visibleRows = [Int]()
for row in 0...((((currentSectionCells) as? NSMutableArray)?.count)! - 1) {
let temp = [currentSectionCells][row] as? NSMutableDictionary
let temp2 = temp?["isVisible"] as! Bool
if temp2 == true {
visibleRows.append(row)
}
}
visibleRowsPerSection.append(visibleRows)
}
}
But this gives me a crash at runtime on this line "let temp2 = temp?["isVisible"] as! Bool"
Crash says "EXC_BAD_INSTRUCTION" and the temp shows as nil.
Please help guys. TIA
Table View Delegate and Data Source
func numberOfSectionsInTableView(tableView: UITableView) -> Int {
if cellDescriptors != nil {
return cellDescriptors.count
}
else {
return 0
}
}
func tableView(_ tableView: UITableView, numberOfRowsInSection section: Int) -> Int {
return visibleRowsPerSection[section].count
}
func tableView(_ tableView: UITableView, cellForRowAt indexPath: IndexPath) -> UITableViewCell {
let currentCellDescriptor = getCellDescriptorForIndexPath(indexPath: indexPath as NSIndexPath)
let cell = tableView.dequeueReusableCell(withIdentifier: currentCellDescriptor["cellIdentifier"] as! String, for: indexPath) as! CustomCell
if currentCellDescriptor["cellIdentifier"] as! String == "sectionCellIdentifier" {
if let primaryTitle = currentCellDescriptor["secondaryTitle"]
{
cell.sectionTitleLabel.text = primaryTitle as? String
}
}
else if currentCellDescriptor["cellIdentifier"] as! String == "shortAnswerCell" {
cell.questionTitle.text = currentCellDescriptor["primaryTitle"] as? String
cell.questionTextView.text = currentCellDescriptor["secondaryTitle"] as? String
cell.answerTextView.text = currentCellDescriptor["answerTitle"] as? String
}
return cell
}
func tableView(_ tableView: UITableView, didSelectRowAt indexPath: IndexPath) {
let indexOfTappedRow = visibleRowsPerSection[indexPath.section][indexPath.row]
let temp = cellDescriptors[indexPath.section] as? NSArray
let temp2 = temp?[indexOfTappedRow ] as? NSDictionary
let temp3 = temp2?["isExpandable"] as! Bool
if temp3 == true {
var shouldExpandAndShowSubRows = false
if temp3 == false {
// In this case the cell should expand.
shouldExpandAndShowSubRows = true
}
temp2?.setValue(shouldExpandAndShowSubRows, forKey: "isExpanded")
for i in (indexOfTappedRow + 1)...(indexOfTappedRow + (temp2?["additionalRows"] as! Int)) {
(temp![i] as AnyObject).setValue(shouldExpandAndShowSubRows, forKey: "isVisible")
}
}
getIndicesOfVisibleRows()
tblExpandable.reloadSections(NSIndexSet(index: indexPath.section) as IndexSet, with: UITableViewRowAnimation.fade)
}

Answer 1

I worked on that tutorial as well and completed it successfully in swift3.Your solution is given below modify accordingly.
class yourClass: UIViewController
{
#IBOutlet weak var profileTableView: UITableView!
internal var visibleRowsPerSection = [[Int]]()
internal var cellDescriptors: NSMutableArray!
// VIEW DID LOAD
override func viewDidLoad() {
super.viewDidLoad()
profileTableView.showsVerticalScrollIndicator = false
loadProfileControllerData()
profileTableSetUp()
// Do any additional setup after loading the view.
}
func loadProfileControllerData(){
if let path = Bundle.main.path(forResource: "CellDescriptor", ofType: "plist") {
cellDescriptors = NSMutableArray(contentsOfFile: path)
}
getIndicesOfVisibleRows()
profileTableView.reloadData()
}
// SHOW PARENT VISIBLE ROWS AND SAVE THERE ROW INDEX IN ARRAY
func getIndicesOfVisibleRows() {
visibleRowsPerSection.removeAll()
for currentSectionCells in cellDescriptors.objectEnumerator().allObjects as! [[[String:Any]]]{
var visibleRows = [Int]()
for row in 0..<currentSectionCells.count {
if currentSectionCells[row]["isVisible"] as! Bool == true {
visibleRows.append(row)
}
}
visibleRowsPerSection.append(visibleRows)
print(visibleRowsPerSection)
}
}
// GET REQUIRED OBJECT OF TYPE [String: Any]
func getCellDescriptorForIndexPath(indexPath: NSIndexPath) -> [String: Any] {
let indexOfVisibleRow = visibleRowsPerSection[indexPath.section][indexPath.row]
let cellDescriptorss = cellDescriptors[indexPath.section] as! NSArray
let data = cellDescriptorss.object(at: indexOfVisibleRow) as! [String:Any]
return data
}
override func didReceiveMemoryWarning() {
super.didReceiveMemoryWarning()
// Dispose of any resources that can be recreated.
}
}
//----------------------
// EXTENSION TO OUR PROFILE CLASS THAT DETERMINE OUR CLASS CONFIRM 2 IMPORTANT DELEGATES
extension profileViewController : UITableViewDelegate,UITableViewDataSource{
//MARK-: TABLE VIEW DELEGATE FUNCTIONS
// RETURN NUMBER OF SECTION IN TABLE VIEW
public func numberOfSections(in tableView: UITableView) -> Int{
if cellDescriptors.count != 0{
return cellDescriptors.count
}
else{
return 0
}
}
// RETURN NUMBER OF ROWS IN EACH SECTION OF TABLE VIEWS
public func tableView(_ tableView: UITableView, numberOfRowsInSection section: Int) -> Int{
return visibleRowsPerSection[section].count
}
/* Return object of UITableViewCell that contains table SECTON data and USER profile data */
func tableView(_ tableView: UITableView, cellForRowAt indexPath: IndexPath) -> UITableViewCell{
let currentCellDescriptor = getCellDescriptorForIndexPath(indexPath: indexPath as NSIndexPath)
let menuCell = tableView.dequeueReusableCell(withIdentifier: currentCellDescriptor["cellIdentifier"] as! String, for: indexPath) as! yourCellClass
if currentCellDescriptor["cellIdentifier"] as! String == "parent"{
}
else if currentCellDescriptor["cellIdentifier"] as! String == "child"{
menuCell.backgroundColor = UIColor.clear
}
return menuCell
}
public func tableView(_ tableView: UITableView, didSelectRowAt indexPath: IndexPath){
let indexOfTappedRow = visibleRowsPerSection[indexPath.section][indexPath.row]
let cellDescriptorss = cellDescriptors[indexPath.section] as! NSArray
var data = cellDescriptorss.object(at: indexOfTappedRow) as! [String:Any]
if data["isExpandable"] as! Bool == true{
var shouldExpandAndShowSubRows = false
if data["isExpanded"] as! Bool == true{
shouldExpandAndShowSubRows = false
(cellDescriptorss[indexOfTappedRow] as AnyObject).setValue(shouldExpandAndShowSubRows, forKey: "isExpanded")
}
for i in (indexOfTappedRow + 1)...(indexOfTappedRow + (data["additionalRows"] as! Int)) {
(cellDescriptorss[i] as AnyObject).setValue(shouldExpandAndShowSubRows, forKey: "isVisible")
}
}
getIndicesOfVisibleRows()
self.profileTableView.reloadSections(NSIndexSet(index: indexPath.section) as IndexSet, with: UITableViewRowAnimation.fade)
}

Answer 2

Thank You for helping me out, I was stuck at a point where the sections weren't expanding even after your help, so just made some changes in the syntax as Swift 3.0 is very specific about type casting hence the didSelectRowAt wasn't functioning properly. Here is the complete didSelectRowAt method. Happy coding.
public func tableView(_ tableView: UITableView, didSelectRowAt indexPath: IndexPath){
let indexOfTappedRow = visibleRowsPerSection[indexPath.section][indexPath.row]
if (cellDescriptors[indexPath.section] as! [[String: AnyObject]])[indexOfTappedRow] ["isExpandable"] as! Bool == true {
var shouldExpandAndShowSubRows = false
if (cellDescriptors[indexPath.section] as! [[String: AnyObject]])[indexOfTappedRow]["isExpanded"] as! Bool == false {
// In this case the cell should expand.
shouldExpandAndShowSubRows = true
}
((cellDescriptors[indexPath.section] as! NSMutableArray)[indexOfTappedRow] as AnyObject).setValue(shouldExpandAndShowSubRows, forKey: "isExpanded")
for i in (indexOfTappedRow + 1)...(indexOfTappedRow + ((cellDescriptors[indexPath.section] as! [[String: AnyObject]])[indexOfTappedRow]["additionalRows"] as! Int)) {
((cellDescriptors[indexPath.section] as! NSMutableArray)[i] as AnyObject).setValue(shouldExpandAndShowSubRows, forKey: "isVisible")
}
}

Answer 3

Swift 3/4 without use of NSMutable arrays based on the tutorial and all the code wrapped in a model.
class CellsDescriptorModel {
private var cellDescriptors: [[[String:Any]]]!
private var visibleRowsPerSection : [[Int]]
var CellDescriptors : [[[String:Any]]] { get { return cellDescriptors }}
var VisibleRowsPerSection : [[Int]] { get { return visibleRowsPerSection }}
init(plist:String) {
visibleRowsPerSection = [[Int]]()
if let url = Bundle.main.url(forResource:plist, withExtension: "plist") {
do {
let data = try Data(contentsOf:url)
cellDescriptors = try PropertyListSerialization.propertyList(from: data, options: [], format: nil) as! [[[String:Any]]]
} catch {
print(error)
}
}
getIndicesOfVisibleRows()
}
func getCellDescriptorForIndexPath(indexPath: IndexPath) -> [String: Any] {
let indexOfVisibleRow = visibleRowsPerSection[indexPath.section][indexPath.row]
return cellDescriptors[indexPath.section][indexOfVisibleRow]
}
func expandCell(indexPath:IndexPath) {
let indexOfTappedRow = visibleRowsPerSection[indexPath.section][indexPath.row]
if cellDescriptors[indexPath.section][indexOfTappedRow] ["isExpandable"] as! Bool == true {
var shouldExpandAndShowSubRows = false
if cellDescriptors[indexPath.section][indexOfTappedRow]["isExpanded"] as! Bool == false {
shouldExpandAndShowSubRows = true
}
cellDescriptors[indexPath.section][indexOfTappedRow]["isExpanded"] = shouldExpandAndShowSubRows
for i in (indexOfTappedRow + 1)...(indexOfTappedRow + (cellDescriptors[indexPath.section][indexOfTappedRow]["additionalRows"] as! Int)) {
cellDescriptors[indexPath.section][i]["isVisible"] = shouldExpandAndShowSubRows
}
}
else {
if cellDescriptors[indexPath.section][indexOfTappedRow]["cellIdentifier"] as! String == "DataPickerTableViewCell" {
var indexOfParentCell: Int!
for index in (0..<indexOfTappedRow).reversed() {
if cellDescriptors[indexPath.section][index]["isExpandable"] as! Bool == true {
indexOfParentCell = index
break
}
}
cellDescriptors[indexPath.section][indexOfParentCell]["secondaryTitle"] = ""
cellDescriptors[indexPath.section][indexOfParentCell]["isExpanded"] = false
for i in (indexOfParentCell + 1)...(indexOfParentCell + (cellDescriptors[indexPath.section][indexOfParentCell]["additionalRows"] as! Int)) {
cellDescriptors[indexPath.section][i]["isVisible"] = false
}
}
}
getIndicesOfVisibleRows()
}
private func getIndicesOfVisibleRows() {
visibleRowsPerSection.removeAll()
for currentSectionCells in cellDescriptors {
var visibleRows = [Int]()
for row in 0..<currentSectionCells.count {
if currentSectionCells[row]["isVisible"] as! Bool == true {
visibleRows.append(row)
}
}
visibleRowsPerSection.append(visibleRows)
}
}
}