I tried so hard to find a similar problem here but couldn't. So, how to save an audio file that has been imported using .fileimporter and save it in a folder in the documents directory. Also how to retrieve them and show their file names in a list in SwiftUI? I hope my question is clear enough. Here is the code that I tried.

import SwiftUI

extension FileManager {
    static func getDocumentsDirectory() -> URL {
        let paths = FileManager.default.urls(for: .documentDirectory, in: .userDomainMask)
        return paths[0]
    }
    
    static let customFolderURL = FileManager.getDocumentsDirectory().appendingPathComponent("Music Files")
}

class Manager: ObservableObject {
    @Published var musicFiles: [URL] = []
    
    init() {
        do {
            try FileManager.default.createDirectory(at: FileManager.customFolderURL, withIntermediateDirectories: true, attributes: nil)
        } catch {
            print("Failed to create folder")
        }
    }
    
    func save(url: URL) {
        if url.startAccessingSecurityScopedResource() {
            do {
                let musicFile = try Data(contentsOf: url)
                try musicFile.write(to: FileManager.customFolderURL, options: .atomic)
                print("Success")
                print(FileManager.customFolderURL)
            } catch {
                print("Failed to save the music file")
            }
            url.stopAccessingSecurityScopedResource()
        } else {
            print("Permission failed!")
        }
    }
    
    func getMusicFiles() {
        do {
            let musicFiles = try FileManager.default.contentsOfDirectory(atPath: FileManager.customFolderURL.path)
            print(musicFiles)
        } catch {
            print("Failed to retrieve items.")
        }
    }
}

struct MainView: View {
    @State private var isFileImporterShown = false
    @State private var isMusicPlayerShown = false
    
    @EnvironmentObject var manager: Manager
    
    var body: some View {
        TabView {
            VStack {
                Button("Import Song") {
                    isFileImporterShown.toggle()
                }
                .padding()
                .fileImporter(isPresented: $isFileImporterShown, allowedContentTypes: [.audio], allowsMultipleSelection: true) { result in
                    do {
                        let url = try result.get().first!
                        if url.startAccessingSecurityScopedResource() {
                            manager.save(url: url)
                        }
                    } catch {
                        
                    }
                }
                
                Button("Show Player") {
                    isMusicPlayerShown.toggle()
                }
                .padding()
                .sheet(isPresented: $isMusicPlayerShown) {
                    MusicPlayerView()
                }
            }
            .tabItem {
                Image(systemName: "externaldrive")
                Text("Load")
            }
            
            AllSongsListView()
                .tabItem {
                    Image(systemName: "music.note.list")
                    Text("Songs")
                }
        }
    }
}

struct AllSongsListView: View {
    @EnvironmentObject var manager: Manager
    var body: some View {
        NavigationView {
            List {
                
            }
            .navigationTitle("Your Songs")
            .onAppear {
                manager.getMusicFiles()
            }
        }
    }
}

CodePudding user response：

The problem with saving is that you're trying to save the file as a directory.

try musicFile.write(to: FileManager.customFolderURL, options: .atomic)

So the to argument is a folder path and not a file path.

You need to change it like this:

let savePath = FileManager.customFolderURL.appendingPathComponent(url.lastPathComponent)
                
try musicFile.write(to: savePath, options: .atomic)

And for displaying the list of imported files you can do something like:

List {
        ForEach(manager.musicFiles, id: \.self) { file in
            Text(file.lastPathComponent)
        }
}

Here is the complete example:

import SwiftUI

extension FileManager {
    static func getDocumentsDirectory() -> URL {
        let paths = FileManager.default.urls(for: .documentDirectory, in: .userDomainMask)
        return paths[0]
    }
    
    static let customFolderURL = FileManager.getDocumentsDirectory().appendingPathComponent("Music Files")
}

class Manager: ObservableObject {
    @Published var musicFiles: [URL] = []
    
    static var shared = Manager()
    
    init() {
        do {
            try FileManager.default.createDirectory(at: FileManager.customFolderURL, withIntermediateDirectories: true, attributes: nil)
        } catch {
            print("Failed to create folder:")
            print(error)
        }
    }
    
    func save(url: URL) {
        if url.startAccessingSecurityScopedResource() {
            do {
                let musicFile = try Data(contentsOf: url)
                let savePath = FileManager.customFolderURL.appendingPathComponent(url.lastPathComponent)
                
                try musicFile.write(to: savePath, options: .atomic)
                print("Success")
                musicFiles.append(savePath)
            } catch {
                print("Failed to save the music file:")
                print(error)
            }
            url.stopAccessingSecurityScopedResource()
        } else {
            print("Permission failed!")
        }
    }
    
    func getMusicFiles() {
        do {
            let musicFiles = try FileManager.default.contentsOfDirectory(atPath: FileManager.customFolderURL.path)
            print(musicFiles)
        } catch {
            print("Failed to retrieve items.")
        }
    }
}

struct MainView: View {
    @State private var isFileImporterShown = false
    @State private var isMusicPlayerShown = false
    
    @ObservedObject var manager = Manager.shared
    
    var body: some View {
        TabView {
            VStack {
                Button("Import Song") {
                    isFileImporterShown.toggle()
                }
                .padding()
                .fileImporter(isPresented: $isFileImporterShown, allowedContentTypes: [.audio], allowsMultipleSelection: true) { result in
                    do {
                        let url = try result.get().first!
                        if url.startAccessingSecurityScopedResource() {
                            manager.save(url: url)
                        }
                    } catch {
                        print(error)
                    }
                }
                
                Button("Show Player") {
                    isMusicPlayerShown.toggle()
                }
                .padding()
                .sheet(isPresented: $isMusicPlayerShown) {
                    Text("Musiker")
                }
            }
            .tabItem {
                Image(systemName: "externaldrive")
                Text("Load")
            }
            
            AllSongsListView()
                .tabItem {
                    Image(systemName: "music.note.list")
                    Text("Songs")
                }
        }
    }
}

struct AllSongsListView: View {
    @ObservedObject var manager = Manager.shared
    
    var body: some View {
        NavigationView {
            List {
                ForEach(manager.musicFiles, id: \.self) { file in
                    Text(file.lastPathComponent)
                }
            }
            .navigationTitle("Your Songs")
            .onAppear {
                manager.getMusicFiles()
            }
        }
    }
}