How to add Pagination with JSON data in collectionview in swift - ios

Question

we need to pass count in JSON parameter like this
var currentPageNumberVM: Int = 0
"count": currentPageNumber
and in service call I'm getting JSON data like below here JSON data is coming and data is showing in collectionview but pagination is not working
func serviceCall(){
self.currentPageNumberVM+=10
let param = ["jsonrpc": "2.0",
"params": ["type" : type, "count": currentPageNumberVM]] as [String : Any]
APIReqeustManager.sharedInstance.serviceCall(param: param, vc: self, url: getUrl(of: .productByFeature), header: header) {(responseData) in
if responseData.error != nil{
self.view.makeToast(NSLocalizedString("Something went wrong!", comment: ""))
}else{
self.viewmoreDB = ViewMoreBase(dictionary: responseData.dict as NSDictionary? ?? NSDictionary())
self.productsData = self.viewmoreDB?.result?.products
self.collectionView.reloadData()
}
}
}
I'm adding values to collectionview like below
func collectionView(_ collectionView: UICollectionView, numberOfItemsInSection section: Int) -> Int {
return productsData?.count ?? 0
}
func collectionView(_ collectionView: UICollectionView, cellForItemAt indexPath: IndexPath) -> UICollectionViewCell {
let cell = collectionView.dequeueReusableCell(withReuseIdentifier: "HorizontalSliderCollectionCell", for: indexPath) as! HorizontalSliderCollectionCell
let indexData = productsData?[indexPath.item]
cell.lblDescrip.text = indexData?.product_by_language?.des
cell.lblTitle.text = indexData?.product_by_language?.title
return cell
}
for pagenation i am trying like below: but nothing works
var isLoading = false
func scrollViewDidScroll(_ scrollView: UIScrollView) {
let offsetY = scrollView.contentOffset.y
let contentHeight = scrollView.contentSize.height
if (offsetY > contentHeight - scrollView.frame.height * 4) && !isLoading {
loadMoreData()
}
}
func loadMoreData() {
if !self.isLoading {
self.isLoading = true
DispatchQueue.global().async {
// Fake background loading task for 2 seconds
sleep(2)
// Download more data here
DispatchQueue.main.async {
self.collectionView.reloadData()
self.isLoading = false
}
}
}
}
How to add pagination to collectionview? .. I mean after loading 10 cells..below need to show activityindicator.. and load another 10 cells
how to do this, please do help me

Answer 1

Could you try this? but first, note that you need to pass the counter as a parameter in your call service function:
This code will be added in your cellForItemAt :
let lastPost = postsArray.count - 1
if lastPost == indexPath.row {
if limit < 100{
limit += 10
callAPI()
}
while callAPI function is:
func callAPI () {
PostService.getPosts(limit: limit) { (postsArray, error) in
if error == nil {
guard let postsArray = postsArray else {return}
self.postsArray = postsArray
DispatchQueue.main.async {
self.postsCollectionView.reloadData()
}
}
}
}
}
Of course, you will change the naming dependent on your project.
Hope it helps