UICollectionView slider image is not showing

Question

I am new to swift I am trying to make a slider using UICollectionView which is working properly,

but when I try to implement cache (Kingfisher) it doesn't show my images in slider

here is my implementation

extension CompanyViewController: UICollectionViewDelegate, UICollectionViewDataSource {


func collectionView(_ collectionView: UICollectionView, numberOfItemsInSection section: Int) -> Int {
   if(self.sliderModel != nil){
    return (self.sliderModel?.data.count)!
   }else{
    return 0
    }
}

func collectionView(_ collectionView: UICollectionView, cellForItemAt indexPath: IndexPath) -> UICollectionViewCell {
    let cell = collectionView.dequeueReusableCell(withReuseIdentifier: "cell", for: indexPath) as! BannerCollectionViewCell
    
     if(self.sliderModel != nil){
        
        if(self.sliderModel.data.count == indexPath.row){
            let url = URL(string:(self.sliderModel?.data[indexPath.row].experienceImage.addingPercentEncoding(withAllowedCharacters: CharacterSet.urlQueryAllowed ))!)
            cell.sliderImageView.kf.setImage(with: url)
        }else{
            //cell.sliderImageView.image = self.imgArr[indexPath.row]
            let url = URL(string:(self.sliderModel?.data[indexPath.row].experienceImage.addingPercentEncoding(withAllowedCharacters: CharacterSet.urlQueryAllowed ))!)
            cell.sliderImageView.kf.setImage(with: url)
        }
    }
    
    return cell
}
}

But Image is not visible in my slider, I checked my model I am getting the response from server and Images are there in image url. May be I am downloading the Image at wrong place.

This is how I am getting my jsondata and assigning it in my model

func getBannerData(){
         dispatchGroup.enter()
        let defaults = UserDefaults.standard
        let appId = defaults.string(forKey: Constants.APPID)
        let token = "Bearer "+defaults.string(forKey: Constants.TOKEN)!
        if let url = URL(string: Constants.EXPERIENCE_BANNER_CENTER+appId!){
            var request = URLRequest(url: url)
            request.httpMethod = "GET"
            request.setValue(token, forHTTPHeaderField:"Authorization")
            APIManager.sharedInstance.getCall(request: request){
                (data) in
                if(!data.isEmpty){
                    do{
                        self.sliderModel = try JSONDecoder().decode(SliderModel.self, from: Data(data.utf8))
                        DispatchQueue.main.async {
                            self.pageView.numberOfPages = (self.sliderModel?.data.count)!
                            self.sliderCollectionView.reloadData()
                           
                        }
                        self.timer = Timer.scheduledTimer(timeInterval: 2.0, target: self, selector: #selector(self.changeImage), userInfo: nil, repeats: true)
                        
                        self.stopActivityIndicator()
                        self.dispatchGroup.leave()
                    }
                    catch{
                        self.stopActivityIndicator()
                        self.showAlertMessage(alertMessage: Constants.COMMON_ERROR)
                    }
                    
                }
            }
        }
    }

Can anyone please suggest what I am doing wrong

Any help would be appreciated

Answer 1

What you are doing is wrong. You cannot network directly in cellForItem. You can ask for the download to begin now if needed, sure, but you cannot keep a reference to cell, because the user might scroll the cell out of view, and it might need to be reused, while the download is still taking place.

Instead, you must download into your model and then reload the collection view.