iOS CollectionView Help (saving current state) - ios

Question

I am making an iOS app in Swift and I am running into a obstacle I seem to be stuck on. I have a collectionview populated by an string array, which are the names of the images I am populating the image within the collectionview cells:
var tableData: [String] = ["cricket1.png", "cricket1.png", "cricket1.png"]
I've linked up the images to the collectionview with the following code:
//How many cells there are is equal to the amount of items in tableData (.count property)
func collectionView(collectionView: UICollectionView, numberOfItemsInSection section: Int) -> Int {
return tableData.count
}
//Linking up collectionView with tableData
func collectionView(collectionView: UICollectionView, cellForItemAtIndexPath indexPath: NSIndexPath) -> UICollectionViewCell {
let cell: CricketCell = collectionView.dequeueReusableCellWithReuseIdentifier("Cell", forIndexPath: indexPath) as! CricketCell
cell.imgCell.image = UIImage(named: tableData[indexPath.row])
return cell
}
When I have the user tap the cell, the image goes from cricket1.png to cricket2.png:
func collectionView(collectionView: UICollectionView, didSelectItemAtIndexPath indexPath: NSIndexPath) {
println("Cell selected")
var cell = collectionView.cellForItemAtIndexPath(indexPath) as! CricketCell
if cell.imgCell.image == UIImage(named:"cricket1.png"){
var cell = collectionView.cellForItemAtIndexPath(indexPath) as! CricketCell
cell.imgCell.image = UIImage(named:"cricket2.png")
}
Now.. here is where I am having trouble. I am currently trying to save data in tableData, however when I do, it always saves it as ["cricket1.png", "cricket1.png", "cricket1.png"]. Even if the image has been tapped and changed to "cricket2.png". Even if all the images on the screen is cricket2.png, when I save tableData, it saves it as ["cricket1.png", "cricket1.png", "cricket1.png"]. I am aware it is because I am storing the variable tableData I declared earlier, but is there any way I can grab a string array of what is on the screen/the current state of the collectionview?
Any help would be appreciated!
Thank you!

Answer 1

You need to update the data in the array yourself. It's independent from image.
func collectionView(collectionView: UICollectionView, didSelectItemAtIndexPath indexPath: NSIndexPath) {
println("Cell selected")
//1: Get the index for which data in array you need to update
let index = indexPath.row
//I don't think this comparison may server your purpose. When you new an UIImage object, it's a different one than the original image. You may want to just compare the data
let unSelectedImage = "cricket1.png"
if self.tableData[index] != unselectedImage {
//2: Update data in array
var cell = collectionView.cellForItemAtIndexPath(indexPath) as! CricketCell
let selectedImageName = "cricket2.png"
self.tableData[index] = selectedImageName
cell.imgCell.image = UIImage(named: selectedImageName)
}
}
So in this case, even you refresh the table, image will loading according to the new tableData.

Answer 2

I would recommend that u use another property to hold the state of the cell. For example,
var selectedState = [true, false, true, true, true]
Upon tapping the image, update the image and selectedState array accordingly.
For example,
if selectedState[indexPath.row] {
cell.imgCell.image == UIImage(named:"cricket1.png")
else {
cell.imgCell.image = UIImage(named:"cricket2.png")
}
Once you are ready to grab the state of the tapped cells, you can use the selectedState array variable.
You can't use the cell to persist any state as the cell can get dequeued by collectionView and may lost its state as you scroll.
Hope this helps.