PetreVane

import Foundation

class TaskManager {
    static let shared = TaskManager()
    
    let session = URLSession(configuration: .default)
    
    typealias completionHandler = (Data?, URLResponse?, Error?) -> Void
    
    var tasks = [URL: [completionHandler]]()

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class ImageFetcher: Operation {
    
    var photo: PhotoRecord
    
    init(photo: PhotoRecord) {
        self.photo = photo
    }
    
    override func main() {

PetreVane

// Stored & computed properties example

struct Person {
    
    // strored properties
    var firstName: String
    var lastName: String
    
    // computed property
    var fullName: String {

PetreVane

import Foundation

enum DataManagerError: Error {

    case Unknown
    case FailedRequest
    case InvalidResponse

}

PetreVane

  
  struct Queue<Element> {
    
    private var elements: [Element] = []
    var description: String {
        return "Your queue has \(elements.count) items: \(elements)"
    }
    
    mutating func enqueue(newElement: Element) {
        elements.append(newElement)

PetreVane

enum MagicError: Error {
    case spellFailure
}

func castSpell(_spell: String) -> Result<String, MagicError> {
    
    switch _spell {
    case "flowers":
        return .success("Flowers falling from sky")
    case "stars":

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1- From Xcode menu open: Product > Scheme > Edit Scheme

2- On your Environment Variables set OS_ACTIVITY_MODE = disable

PetreVane

func fetchImageWithFileManager(image: String) -> UIImage? {

    if let pathUrl = FileManager.default.urls(for: .documentDirectory, in: .userDomainMask)[0] {
        let dirURL = pathUrl.appendingPathComponent(image)
        do {
            let imageData = try Data(contentsOf: dirURL)
            return UIImage(data: imageData)
        } catch {
            print("Failed loading image")

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class ErrorManager {

  static func showError(message: String, on viewController: UIViewController?, dismissAction: ((UIAlertAction) -> Void)? = nil) {
    weak var currentViewController = viewController
    DispatchQueue.main.async {
      let alertController = UIAlertController(title: "Error", message: message, preferredStyle: .alert)
      alertController.addAction(UIAlertAction(title: "Dismiss", style: .default, handler: dismissAction))

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    override func prepare(for segue: UIStoryboardSegue, sender: Any?) {
        
        if segue.identifier == "showDetailedImage" {
            
            guard let indexPath = tableView.indexPathForSelectedRow,
            let destinationVC = segue.destination as? DetailsVC else {return}
            
            let imageToBePassed = UIImage(named: testImages[indexPath.row])