Open and View Document file Url

Question

How to open and view url of documents file which is got from web service using QLPreviewController.

Answer 1

You can't do this. The documentation can explain well about this, but, you would like try to make your own viewer. Good luck!

See:

Oficial topic IOS

You can make as the site show: "Creating and Configuring a Document Interaction Controller"

- (UIDocumentInteractionController *) setupControllerWithURL: (NSURL) fileURL
usingDelegate: (id <UIDocumentInteractionControllerDelegate>) interactionDelegate {

UIDocumentInteractionController *interactionController =
    [UIDocumentInteractionController interactionControllerWithURL: fileURL];
interactionController.delegate = interactionDelegate;

return interactionController;}

"Once you have a document interaction controller, you can use its properties to get information about the associated file including its name, type, and URL."

Answer 2

1. Display some kind of progress spinner.
2. Download the file to your ~/documents folder using URLSession and URLSessionDownloadTask.
3. Hide progress spinner.
4. Then you need to create an instance of a class that implements QLPreviewControllerDataSource and holds your document.

5. Hide progress spinner and present QLPreviewController

   import UIKit
   import QuickLook
   
   
   class Document: NSObject, QLPreviewItem {
       var previewItemURL: URL?
   }
   
   class PreviewDataSource: NSObject, QLPreviewControllerDataSource {
   
       var document: Document?
   
       func numberOfPreviewItems(in controller: QLPreviewController) -> Int {
           return document != nil ? 1 : 0
       }
   
       func previewController(_ controller: QLPreviewController, previewItemAt index: Int) -> QLPreviewItem {
           return document!
       }
   }
   
   class ProgressLoadingViewController: UIViewController {
   
       var session: URLSession = URLSession(configuration: URLSessionConfiguration.default)
       var downloadTask: URLSessionDownloadTask?
   
       var dataSource: PreviewDataSource?
   
       override func viewDidLoad() {
           super.viewDidLoad()
           startDownload()
       }
   
       func startDownload() {
           // start progres spinner
           downloadTask = session.downloadTask(with: URL(string: "http://che.org.il/wp-content/uploads/2016/12/pdf-sample.pdf")!) { [weak self] (downloadLocation, response, error) in
               guard // check if download went correctly
                   error != nil,
                   let filename = response?.suggestedFilename,
                   let downloadLocation = downloadLocation
                   else {
                       print("Something went wrong: \(error!)")
                       return
               }
   
               // copy file
               let fileManager = FileManager.default
               let targetPath = URL(fileURLWithPath: filename, relativeTo: fileManager.temporaryDirectory)
               do {
                   try fileManager.copyItem(at: downloadLocation, to: targetPath)
               } catch let fileError {
                   print("Copying failed: \(fileError)")
                   return
               }
   
               // prepare preview
               let document = Document()
               document.previewItemURL = targetPath
               self?.dataSource? = PreviewDataSource()
               self?.dataSource?.document = document
   
               let qlViewController = QLPreviewController()
               qlViewController.dataSource = self?.dataSource
   
               // hide progress spinner
               self?.present(qlViewController, animated: true) {
                   self?.downloadTask = nil
                   qlViewController.reloadData()
               }
           }
           downloadTask?.resume()
       }
   }
   

Of course this long completion function should be split up into several and then moved to its own class DocumentDownloadManager.