PHPickerHandler.swift

import UniformTypeIdentifiers
import PhotosUI

@available(iOS 14, *)
extension PHPickerResult {
    var fileName: String? {
        guard let name = itemProvider.suggestedName else { return nil }
        
        if let extn = itemProvider.itemType?.preferredFilenameExtension {
            return name + ".\(extn)"
        }
        
        return name
    }
}

@available(iOS 14.0, *)
extension NSItemProvider {
    
    func loadData(onCompletion handler: @escaping (Result<Data, Error>) -> Void) {
        
        guard let type = itemType else {
            handler(.failure(LocalError.unknownType))
            return
        }
        
        loadDataRepresentation(forTypeIdentifier: type.identifier) { data, error in
            DispatchQueue.main.async {
                if let existingData = data {
                    handler(.success(existingData))
                } else if let existingError = error {
                    handler(.failure(existingError))
                } else {
                    handler(.failure(LocalError.unknown))
                }
            }
        }
    }
    
    var itemType: UTType? {
        if let lastID = registeredTypeIdentifiers.last {
            return UTType(lastID)
        }
        
        let preferredTypes: [UTType] = [.png,.gif,.heic,.heif,.jpeg,.livePhoto,
                                        .mpeg,.mpeg2Video,.mpeg4Movie,.quickTimeMovie,
                                        .image,.video,.movie]
        
        for type in preferredTypes where self.hasItemConformingToTypeIdentifier(type.identifier) {
            return type
        }
        
        return nil
    }
}

enum LocalError: Error {
    case unknownType
    case unknown
}