How to set enabled checkimage in tableview based on the selected cells - ios

Question

I am fetching previously selected categorylist from the server. say for an example.cateogrylist i fetched from the server was in following formate
categoryid : 2,6,12,17
now what i need to do is want to enable checkmark in my tableview based on this categorylist,for that purpose i converted this list into an [Int] array like this :
func get_numbers(stringtext:String) -> [Int] {
let StringRecordedArr = stringtext.components(separatedBy: ",")
return StringRecordedArr.map { Int($0)!}
}
in viewDidLoad() :
selectedCells = self.get_numbers(stringtext: UpdateMedicalReportDetailsViewController.catId)
print(myselection)
while printing it's giving me results like this : [12,17,6,8,10]
i want to enable checkimage based on this array.I tried some code while printing its giving me the right result like whatever the categories i selected at the time of posting ,i am able to fetch it but failed to place back this selection in tableview.Requirement : while i open this page it should show me the selection based on the categorylist i fetched from the server.
var selectedCells : [Int] = []
func tableView(_ tableView: UITableView, cellForRowAt indexPath: IndexPath) -> UITableViewCell
{
let cell1 = table.dequeueReusableCell(withIdentifier: "mycell") as! catcell
cell1.mytext.text = categoriesName[indexPath.row]
if UpdateMedicalReportDetailsViewController.flag == 1
{
selectedCells = self.get_numbers(stringtext: UpdateMedicalReportDetailsViewController.catId)
cell1.checkimage.image = another
print(selectedCells)
}
else
{
selectedCells = []
cell1.checkimage.image = myimage
}
return cell1
}
func tableView(_ tableView: UITableView, didSelectRowAt indexPath: IndexPath) {
let cell = table.cellForRow(at: indexPath) as! catcell
cell.checkimage.image = myimage
if cell.isSelected == true
{
self.selectedCells.append(indexPath.row)
cell.checkimage.image = another
}
}
func tableView(_ tableView: UITableView, didDeselectRowAt indexPath: IndexPath) {
let cell = table.cellForRow(at: indexPath) as! catcell
if cell.isSelected == false
{
self.selectedCells.remove(at: self.selectedCells.index(of: indexPath.row)!)
cell.checkimage.image = myimage
}
}
output :

Answer 1

This is a very common use case in most apps. I'm assuming you have an array of all categories, and then an array of selected categories. What you need to do is in cellForRowAtIndexPath, check to see if the current index path row's corresponding category in the "all categories" array is also present in the "selected categories" array. You can do this by comparing id's etc.
If you have a match, then you know that the cell needs to be selected/checked. A clean way to do this is give your cell subclass a custom load method and you can pass a flag for selected/checked.
func tableView(_ tableView: UITableView, cellForRowAt indexPath: IndexPath) -> UITableViewCell {
let cell = table.dequeueReusableCell(withIdentifier: "mycell") as! catcell
let category = self.categories[indexPath.row] // Let's say category is a string "hello"
Bool selected = self.selectedCategories.contains(category)
cell.load(category, selected)
return cell
}
So with the code above, let's say that categories is just an array of category strings like hello, world, and stackoverflow. We check to see if the selectedCategories array contains the current cell/row's category word.
Let's say that the cell we're setting up has a category of hello, and selectedCategories does contain it. That means the selected bool gets set to true.
We then pass the category and selected values into the cell subclass' load method, and inside that load method you can set the cell's title text to the category and you can check if selected is true or false and if it's true you can display the checked box UI.