Expand and collapse multilevel sections in uitableview swift4 - ios

Question

I want to expand and collpase the multilevel array in uitableview like the following
Cat1
SubCat1
Info 1
Info 2
SubCat2
Info 1
Info 2
SubCat3
Info 1
Info 2
Cat2
SubCat1
Info 1
Info 2
For that purpose I have done the following code.
struct CellData {
var opened = Bool()
var subCatTitle = String()
var subCatList = [String]()
}
struct MainModel {
var opened = Bool()
var categoryTitle = String()
var categoryList = [CellData]()
}
I have made the list
#IBOutlet var expandableThreeStageTableView: UITableView!
var arrayList = [CellData]()
var expandableList = [MainModel]()
func loadData(){
arrayList.append(CellData(opened: false, subCatTitle: "SubCat1", subCatList: ["Info1","Info2","Info3"]))
arrayList.append(CellData(opened: false, subCatTitle: "SubCat2", subCatList: ["Info1","Info2","Info3"]))
arrayList.append(CellData(opened: false, subCatTitle: "SubCat3", subCatList: ["Info1","Info2"]))
arrayList.append(CellData(opened: false, subCatTitle: "SubCat4", subCatList: ["Info1"]))
expandableList.append(MainModel(opened: true, categoryTitle: "Cat1", categoryList: arrayList))
expandableList.append(MainModel(opened: false, categoryTitle: "Cat2", categoryList: arrayList))
expandableList.append(MainModel(opened: false, categoryTitle: "Cat3", categoryList: arrayList))
}
And delegate, datasource methods are given below
extension TextFieldAsSearchVC : UITableViewDataSource{
func numberOfSections(in tableView: UITableView) -> Int {
return expandableList.count
}
func tableView(_ tableView: UITableView, numberOfRowsInSection section:
Int) -> Int {
if expandableList[section].opened{
if expandableList[section].categoryList[section].opened{
return
expandableList[section].categoryList[section].subCatList.count////which extra count should return here
}else{
print("COUNT ",expandableList[section].categoryList.count)
return expandableList[section].categoryList.count +
1///here +1 is for catname + subcatname
}
}else{
return 1
}
}
func tableView(_ tableView: UITableView, cellForRowAt indexPath:
IndexPath) -> UITableViewCell {
if indexPath.row == 0{
let cell =
expandableThreeStageTableView.dequeueReusableCell(withIdentifier:
"TextFieldAsSearchVCCell", for: indexPath) as! TextFieldAsSearchVCCell
cell.lblValue.text =
expandableList[indexPath.section].categoryTitle
return cell
}else if indexPath.row <=
expandableList[indexPath.section].categoryList.count{
let cell =
expandableThreeStageTableView.dequeueReusableCell(withIdentifier:
"SectionDataCell", for: indexPath) as! SectionDataCell
cell.rowLabel.text =
expandableList[indexPath.section].categoryList[indexPath.row -
1].subCatTitle
return cell
}
else{
let cell =
expandableThreeStageTableView.dequeueReusableCell(withIdentifier:
"SectionDataCell", for: indexPath) as! SectionDataCell
cell.rowLabel.text =
expandableList[indexPath.section].categoryList[indexPath.row].
subCatList[indexPath.row]//how to access rows in subcategories
return cell
}
}
}
extension TextFieldAsSearchVC : UITableViewDelegate{
func tableView(_ tableView: UITableView, didSelectRowAt indexPath:
IndexPath) {
if indexPath.row == 0{
if expandableList[indexPath.section].opened{
expandableList[indexPath.section].opened = false
//now reload the section
let sections = IndexSet(integer: indexPath.section)
expandableThreeStageTableView.reloadSections(sections,
with: .automatic)
}else{
expandableList[indexPath.section].opened = true
//now reload sections
let sections = IndexSet(integer: indexPath.section)
expandableThreeStageTableView.reloadSections(sections,
with: .automatic)
}
}else {
if
expandableList[indexPath.section].categoryList[indexPath.row].opened{
expandableList[indexPath.section].categoryList[indexPath.row].opened =
false
expandableThreeStageTableView.reloadRows(at:
[IndexPath(index: indexPath.row)], with: .automatic)
}else{
expandableList[indexPath.section].categoryList[indexPath.row].opened =
true
expandableThreeStageTableView.reloadRows(at:
[IndexPath(index: indexPath.row)], with: .automatic)
}
}
}
}
From above code I can expand and collapse the Categories but not Subcategories.. When I tried to click on Subcategories it gives me an error
*** Terminating app due to uncaught exception
'NSInternalInconsistencyException', reason: 'Invalid index path for use
with UITableView. Index paths passed to table view must contain exactly
two indices specifying the section and row. Please use the category on
NSIndexPath in NSIndexPath+UIKitAdditions.h if possible.'
How to deal with such type of logic?

Answer 1

The specific error you are getting occurs in this line:
expandableThreeStageTableView.reloadRows(at:
[IndexPath(index: indexPath.row)], with: .automatic)
An IndexPath needs both, a row and a section; you're only providing a row. So it should be something like this:
expandableThreeStageTableView.reloadRows(at:
[IndexPath(row: indexPath.row, section: indexPath.section)], with: .automatic)
If you really only need to reload the current indexPath, simply call it like this:
expandableThreeStageTableView.reloadRows(at:
[indexPath], with: .automatic)
This would fix the error you are getting, but I don't know if that solves your problem or not.