Present native ios Files app a specific folder from my app - ios

Question

I have an app say called MyApp it is primarily wkwebview. It is already integrated to Files app so I can import/export files from my wkwebview to be able to download files to local machine or upload files to the server.
Finally I am trying to build a UIbutton in my app that will allow my users to Jump into Files app in the folder where I am storing all their content. Instead of building a full FileProviderUI into my app, I just want the button to take the user into the Files App navigating to the folder.
When I give the path for UIDocumentInteractionController to be a directory and do a shared open to present it, nothing happens. No error, nothing at at all. I just want the user to be able to Jump into the folder called MyApp inside the Files app.
I thought it will be very simple. Adding a FileProvider extension or FilePRoviderUI extension seems superflous to just jump the user into this folder and let him interact with Files app to do whatever he likes - open/delete/modify document.
I have to assume that the users are not savvy enough to know even if I tell them that files are saved in Files App for them to be able to interact with directly when they are offline!
let documentsUrl = FileManager.default.urls(for: .documentDirectory, in: .userDomainMask).first!
// Just jump to the folder forcing Files app to open this
let viewer = UIDocumentInteractionController(documentsUrl)
viewer.delegate = self
viewer.presentPreview(animated: true)
Nothing gets presented to the user and nothing happens. The button tap just quietly fails.

Answer 1

I think I figured this out. There is a specific URL format that will automatically open the Files app it is shareddocuments:// - Here is a simple function that seems to achieve this quiet simply.
func openSharedFilesApp() {
let documentsUrl = FileManager.default.urls(for: .documentDirectory, in: .userDomainMask).first!
let sharedurl = documentsUrl.absoluteString.replacingOccurrences(of: "file://", with: "shareddocuments://")
let furl:URL = URL(string: sharedurl)!
UIApplication.shared.open(furl, options: convertToUIApplicationOpenExternalURLOptionsKeyDictionary([:]), completionHandler: nil)
}

Answer 2

Thanks, Vijay. Here it is in Objective-C.
- (void) openSharedFilesApp
{
NSArray<NSString *>* directories = NSSearchPathForDirectoriesInDomains(NSDocumentDirectory, NSUserDomainMask, YES); // yes = expand tilde
NSURL* url = [NSURL fileURLWithPath:directories.firstObject];
NSString* sharedDocumentPath = [url.absoluteString stringByReplacingOccurrencesOfString:#"file://" withString:#"shareddocuments://"];
NSURL* sharedDocumentURL = [NSURL URLWithString:sharedDocumentPath];
[UIApplication.sharedApplication openURL:sharedDocumentURL options:#{UIApplicationOpenURLOptionUniversalLinksOnly: #(NO)} completionHandler:^(BOOL success) {
}];
}

Answer 3

Adding to #Vijay's answer in iOS 15, Swift 5:
let documentsUrl = FileManager.default.urls(for: .documentDirectory, in: .userDomainMask).first!
let sharedurl = documentsUrl.absoluteString.replacingOccurrences(of: "file://", with: "shareddocuments://")
let furl:URL = URL(string: sharedurl)!
if UIApplication.shared.canOpenURL(furl) {
UIApplication.shared.open(furl, options: [:])
}