CODEWITHSUNDEEP
iosswiftuitableviewamazon-s3
pastelsdev
pastelsdev

Reputation: 145

How to avoid file upload duplication using Swift 4

I am trying to upload files into AWS S3. Files I am selecting from iCloud and appending into array for listing in tableView and same time calling AWS S3 upload function.

Here, once file uploaded successfully I need to make some identification inside array because whenever I am trying to upload next file, my array again pushing already stored files. So, The upload process giving duplication results. How to avoid this problem?

My complication if i remove uploaded file url from array then I can't able to list in tableView but If I didn't remove, Then it will be re-uploading whenever I am trying to upload new file. 

// Array declaration
var items = [Item]()
var fileArray = [Item]() 

// Values appending into my array
items.append(Item(indexPath: indexPath, file: item.url))

// TableView data-load 
func tableView(_ tableView: UITableView, cellForRowAt indexPath: IndexPath) -> UITableViewCell {

    let cell = tableView.dequeueReusableCell(withIdentifier: "cell", for: indexPath) as! CustomTableViewCell
    let item = fileArray[indexPath.row]

       if fileArray.count > 0 {
            cell.url_label.text = item.url

            // Upload function call
            DispatchQueue.main.asyncAfter(deadline: .now() + 1.0, execute: {
                self.uploadData(indexPath: indexPath, file: item.url)
            })
       }
   return cell
} 

// Upload function with parameters 
private func uploadData(indexPath: indexPath, file: item.url) {

   // Tracking each cell and it's file. 
   // Once, file uploaded I am doing some changes in tableview cell
}

Upvotes: 1

Views: 109

Answers (1)

Shehata Gamal
Shehata Gamal

Reputation: 100503

1- You shouldn't do any non-ui tasks inside 

DispatchQueue.main.asyncAfter(deadline: .now() + 1.0, execute: {

2- You shouldn't upload files inside cellForRowAt as it's called every scroll so for sure you'll encounter a duplication , if you want to only do this for visible cells , then inside the array model create a status property of type Enum to indicate the current state of this file -> NotUploaded-Uploaded-Uploading and check it before upload

Enum Status {
  case  notUploaded,uploaded,uploading 
}

class Item {
  var st:Status = .notUploaded
  func upload () {
    if st == .notUploaded {
      st =.uploading 
      // upload here
      API.upload {
        self.st = .uploaded 
      }
    }
  }
}

Upvotes: 1

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