I have a "Share on Facebook" button in my app at 3 different view controllers. So I wrote a class which name is "ShareCentral" and i want to do all sharing operations in this class. But for showing share dialog i need to pass uiviewcontroller to my ShareCentral class. I did like that:
class ShareCentral {
var UIVC: UIViewController
init(vc:UIViewController) {
self.UIVC = vc
}
func shareOnFacebook() {
var content = LinkShareContent(url: URL(string:userProfileLink)!)
do {
try ShareDialog.show(from: UIVC, content: content)
}catch (let error) {
print(error)
}
}
}
And this is my view controller:
class SettingsViewController: UIViewController {
let shareCentral = ShareCentral(vc: self)
#IBAction func shareButtonClicked(_ sender: AnyObject) {
self.shareCentral.shareOnFacebook()
}
}
I am getting following compiler error:
SettingsViewController.swift:40:41: Cannot convert value of type '(SettingsViewController) -> () -> (SettingsViewController)' to expected argument type 'UIViewController'
I know if i change the type of UIVC to "SettingsViewController" the problem will disappear. But as i said before i am gonna use this method in three different view controllers.
How can i resolve this problem?
Try this instead :
class ShareCentral {
unowned var UIVC: UIViewController
init(vc:UIViewController) {
self.UIVC = vc
}
func shareOnFacebook() {
var content = LinkShareContent(url: URL(string:userProfileLink)!)
do {
try ShareDialog.show(from: UIVC, content: content)
} catch (let error) {
print(error)
}
}
}
class SettingsViewController: UIViewController {
var shareVC: ShareVC!
override func viewDidLoad() {
super.viewDidLoad()
self.shareVC = ShareVC(vc: self)
}
#IBAction func shareButtonClicked(_ sender: AnyObject) {
self.shareCentral.shareOnFacebook()
}
}
Related
My Model saves data to Firestore. Once that data is saved, I'd like it to alert my ViewController so that a function can be called. However, nothing is being passed to my ViewController.
This is my Model:
protocol ProtocolModel {
func wasDataSavedSuccessfully(dataSavedSuccessfully:Bool)
}
class Model {
var delegate:ProtocolModel?
func createUserAddedRecipe(
docId:String,
completion: #escaping (Recipe?) -> Void) {
let db = Firestore.firestore()
do {
try db.collection("userFavourites").document(currentUserId).collection("userRecipes").document(docId).setData(from: recipe) { (error) in
print("Data Saved Successfully") // THIS OUTPUTS TO THE CONSOLE
// Notify delegate that data was saved to Firestore
self.delegate?.wasDataSavedSuccessfully(dataSavedSuccessfully: true)
}
}
catch {
print("Error \(error)")
}
}
}
The print("Data Saved Successfully") outputs to the console, but the delegate method right below it doesn't get called.
And this is my ViewController:
class ViewController: UIViewController {
private var model = Model()
override func viewDidLoad() {
super.viewDidLoad()
model.delegate = self
}
}
extension ViewController: ProtocolModel {
func wasDataSavedSuccessfully(dataSavedSuccessfully: Bool) {
if dataSavedSuccessfully == true {
print("Result is true.")
}
else {
print("Result is false.")
}
print("Protocol-Delegate Pattern Works")
}
}
Is there something I'm missing from this pattern? I haven't been able to notice anything different in the articles I've reviewed.
So I test your code and simulate something like that
import UIKit
protocol ProtocolModel {
func wasDataSavedSuccessfully(dataSavedSuccessfully:Bool)
}
class Model {
var delegate:ProtocolModel?
// I use this timer for simulate that firebase store data every 3 seconds for example
var timer: Timer?
func createUserAddedRecipe(
docId:String) {
timer = Timer.scheduledTimer(withTimeInterval: 3, repeats: true, block: { _ in
self.delegate?.wasDataSavedSuccessfully(dataSavedSuccessfully: true)
})
}
}
class NavigationController: UINavigationController {
var model = Model()
override func viewDidLoad() {
super.viewDidLoad()
model.delegate = self
// Call this method to register for network notification
model.createUserAddedRecipe(docId: "exampleId")
}
}
extension NavigationController: ProtocolModel {
func wasDataSavedSuccessfully(dataSavedSuccessfully: Bool) {
print(#function)
}
}
so you can see the result as image below, my delegate update controller that conform to that protocol.
I am using delegates to get a string value from my modal. When the modal closes I am trying to update Label text using that string. However, I am getting error: Unexpectedly found nil while implicitly unwrapping an Optional value: file. I am not sure how to fix this. I think it's happening because the view is not yet active.
import Cocoa
class ViewControllerA: NSViewController, SomeDelegate {
#IBOutlet weak var msgLabel: NSTextField!
var s: String = "";
override var representedObject: Any? {
didSet {
// Update the view, if already loaded.
}
}
func setDetails(s: String) {
self.user = s;
print("Notified", self.s) // <-- prints: Notified hello again
msgLabel.stringValue = self.s <-- DOESN'T WORK
}
func showModal() -> Void {
msgLabel.stringValue = "hello" // <--- WORKS
let cbvc: NSViewController = {
return self.storyboard!.instantiateController(withIdentifier: "ControllerBVC")
as! NSViewController
}()
self.presentAsModalWindow(cbvc);
}
#IBAction func onBtn(_ sender: Any) {
self.showModal();
}
}
protocol SomeDelegate {
func setDetails(s: String)
}
class ViewControllerB: NSViewController {
#IBOutlet weak var textF: NSTextField!
var delegate: SomeDelegate?
override func viewDidLoad() {
super.viewDidLoad()
// Do view setup here.
let vc = ViewControllerA()
self.delegate = vc
}
#IBAction func onBtn(_ sender: Any) {
DispatchQueue.main.async {
self.delegate?.setDetails(s: self.textF.stringValue)
self.dismiss("ControllerAVC")
}
}
}
You have a number of problems.
In ViewControllerB.viewDidLoad you are assigning a new instance of ViewControllerA to the delegate property. Don't do that. Your viewDidLoad method should look like this:
override func viewDidLoad() {
super.viewDidLoad()
}
In the showModal method ViewControllerA should assign itself as the delegate on ViewControllerB before ViewControllerB it is presented.
func showModal() -> Void {
let cbvc: NSViewController = {
let vc = self.storyboard!.instantiateController(withIdentifier: "ControllerBVC")
as! ViewControllerB
vc.delegate = self
return vc
}()
self.presentAsModalWindow(cbvc);
}
In the setDetails method just assign the string to your text field directly:
func setDetails(s: String) {
msgLabel.stringValue = s
}
I would like to understand what would be the best way to implement a delegate out UIViewController class
How can I manage the delegate using controller: UIViewController parameter of my function in AuthManager?
These are the two classes I'm working with .. I show you small examples to make you understand
class StartController: UIViewController {
#objc private func presentAuthFacebookController() {
AuthManager.signInWithFacebook(controller: self)
}
}
class AuthManager {
static func signInWithFacebook(controller: UIViewController) {
let loginManager = LoginManager()
loginManager.logIn(permissions: [.publicProfile, .email], viewController: controller) { (result) in
switch result {
case .cancelled : print("\n AuthFacebook: operazione annullata dall'utente \n")
case .failed(let error) : print("\n AuthFacebook: \(error) \n")
case .success(granted: _, declined: let declinedPermission, token: _):
let authVC = ExistingEmailController()
authVC.delegate = // ?????? (controller)
UIApplication.shared.windows.first?.rootViewController?.present(authVC, animated: true, completion: nil)
}
}
}
}
I personally don't think StartController should know about/conform to ExistingEmailControllerDelegate. But if you really want, you can declare controller as a composition type:
static func signInWithFacebook(controller: UIViewController & ExistingEmailControllerDelegate) {
...
authVC.delegate = controller
In my opinion, the whole point of having a AuthManager is to create a layer of abstraction on top of ExistingEmailController, and to encapsulate the logic of authentication. Therefore, StartController shouldn't know, or care, about ExistingEmailControllerDelegate. It only knows about AuthManager.
AuthManager should be the delegate of ExistingEmailController, which implies that signInWithFacebook should not be static, and AuthManager can have an AuthManagerDelegate that StartController conforms to:
class AuthManager : ExistingEmailControllerDelegate {
weak var delegate: AuthManagerDelegate?
func signInWithFacebook(controller: UIViewController) {
...
let authVC = ExistingEmailController()
authVC.delegate = self
UIApplication.shared.windows.first?.rootViewController?.present(authVC, animated: true, completion: nil)
}
func someMethodFromExistingEmailControllerDelegate() {
delegate?.someMethod() // delegating it self.delegate, which StartController conforms to
}
}
protocol AuthManagerDelegate : class {
func someMethod()
}
class StartController: UIViewController, AuthManagerDelegate {
var authManager: AuthManager!
override func viewDidLoad() {
authManager = AuthManager()
authManager.delegate = self
}
#objc private func presentAuthFacebookController() {
authManager.signInWithFacebook(controller: self)
}
func someMethod() {
// write here the code that you would have written in someMethodFromExistingEmailControllerDelegate
}
}
I found Router in Clean Swift architecture is responsible to navigate and pass data between view controllers. Some samples and articles depict that Routers use segue to communicate with view controllers. What would be the convenient design when I don't want to use any segue from Storyboard. Is it possible to pass data without segue in Clean Swift? If you describe with simplest complete example, would be appreciated.
Article says that you can:
// 2. Present another view controller programmatically
You can use this to manually create, configure and push viewController.
Example.
Let's pretend that you have ViewController with button (handle push):
final class ViewController: UIViewController {
private var router: ViewControllerRouterInput!
override func viewDidLoad() {
super.viewDidLoad()
router = ViewControllerRouter(viewController: self)
}
#IBAction func pushController(_ sender: UIButton) {
router.navigateToPushedViewController(value: 1)
}
}
This ViewController has router that implements ViewControllerRouterInput protocol.
protocol ViewControllerRouterInput {
func navigateToPushedViewController(value: Int)
}
final class ViewControllerRouter: ViewControllerRouterInput {
weak var viewController: ViewController?
init(viewController: ViewController) {
self.viewController = viewController
}
// MARK: - ViewControllerRouterInput
func navigateToPushedViewController(value: Int) {
let pushedViewController = PushedViewController.instantiate()
pushedViewController.configure(viewModel: PushedViewModel(value: value))
viewController?.navigationController?.pushViewController(pushedViewController, animated: true)
}
}
The navigateToPushedViewController func can takes any parameter you want (it is good to encapsulate parameters before configure new vc, so you may want to do that).
And the PushedViewController hasn't any specific implementation. Just configure() method and assert (notify you about missing configure() call):
final class PushedViewModel {
let value: Int
init(value: Int) {
self.value = value
}
}
final class PushedViewController: UIViewController, StoryboardBased {
#IBOutlet weak var label: UILabel!
private var viewModel: PushedViewModel!
func configure(viewModel: PushedViewModel) {
self.viewModel = viewModel
}
override func viewDidLoad() {
super.viewDidLoad()
assert(viewModel != nil, "viewModel is nil. You should call configure method before push vc.")
label.text = "Pushed View Controller with value: \(viewModel.value)"
}
}
Note: also, i used Reusable pod to reduce boilerplate code.
Result:
As above article explained you can use option 2/3/4 of navigateToSomewhere method as per your app design.
func navigateToSomewhere()
{
// 2. Present another view controller programmatically
// viewController.presentViewController(someWhereViewController, animated: true, completion: nil)
// 3. Ask the navigation controller to push another view controller onto the stack
// viewController.navigationController?.pushViewController(someWhereViewController, animated: true)
// 4. Present a view controller from a different storyboard
// let storyboard = UIStoryboard(name: "OtherThanMain", bundle: nil)
// let someWhereViewController = storyboard.instantiateInitialViewController() as! SomeWhereViewController
// viewController.navigationController?.pushViewController(someWhereViewController, animated: true)
}
You need pass data across protocols
protocol SecondModuleInput {
// pass data func or variable
var data: Any? { get set }
}
protocol SecondModuleOutput {
// pass data func or variable
func send(data: Any)
}
First presenter
class FirstPresenter: SecondModuleOutput {
var view: UIViewController
var secondModuleInputHandler: SecondModuleInput?
// MARK: SecondModuleInput
func send(data: Any) {
//sended data from SecondPresenter
}
}
Second presenter
class SecondPresenter: SecondModuleInput {
var view: UIViewController
var secondModuleOutputHandler: SecondModuleOutput?
static func configureWith(block: #escaping (SecondModuleInput) -> (SecondModuleOutput)) -> UIViewController {
let secondPresenter = SecondPresenter()
secondPresenter.secondModuleOutputHandler = block(secondPresenter)
return secondPresenter.view
}
// Sending data to first presenter
func sendDataToFirstPresenter(data: Any) {
secondModuleOutputHandler?.send(data: data)
}
// MARK: FirstModuleInput
var data: Any?
}
Router
class FirstRouter {
func goToSecondModuleFrom(firstPresenter: FirstPresenter, with data: Any) {
let secondPresenterView = SecondPresenter.configureWith { (secondPreseter) -> (SecondModuleOutput) in
firstPresenter.secondModuleInputHandler = secondPreseter
return firstPresenter
}
//Pass data to SecondPresenter
firstPresenter.secondModuleInputHandler?.data = data
//Go to another view controller
//firstPresenter.view.present(secondPresenterView, animated: true, completion: nil)
//firstPresenter.view.navigationController.pushViewController(secondPresenterView, animated: true)
}
}
I have a parent ui view controller and it has a method responsible for printing data to the console:
func printSomeData() {
print("printing some data")
}
It also has a container with embedded UITableViewController. The table itself has a pull to refresh functionality implemented and it prints the string when user pulls the table:
func refresh(refreshControl: UIRefreshControl) {
print("Refreshing!!")
refreshControl.endRefreshing()
}
Now I want to call printsomeData from the refresh method.
This is what I try:
parent UIViewController:
class MainMenu: UIViewController, printing{
func printSomeData() {
print("some date")
}
}
embedded UITableViewController:
protocol printing{
func printSomeData()
}
class MainMenuTableViewController: UITableViewController {
var delegate: printing?
func refresh(refreshControl: UIRefreshControl) {
print("Refreshing!!")
if let _ = delegate{
delegate?.printSomeData()
}
refreshControl.endRefreshing()
}
But now when I pull the table I only see Refreshing!!, there is no way I could see printing some data. What am I doing wrong?
Where are you assigning the delegate?
And write the optional method call as a single line
delegate?.printSomeData()
or like that:
if self.delegate != nil {
self.delegate!.printSomeData()
}
Inside MainMenu
override func viewDidLoad() {
super.viewDidLoad()
// tableViewController is placeholder for `MainMenuTableViewController` reference
tableViewController.delegate = self
}
If i have understand you correctly and the MainMenu has a ContainerView with MainMenuTableViewController than should this solve your problem:
class MainMenu: UIViewController, Printer {
func printSomeData() {
print("some date")
}
}
protocol Printer {
func printSomeData()
}
class MainMenuTableViewController: UITableViewController {
var printer: Printer? {
guard let printer = self.parentViewController as? Printer else {
return nil
}
return printer
}
func refresh(refreshControl: UIRefreshControl) {
print("Refreshing!!")
printer?.printSomeData()
refreshControl.endRefreshing()
}
}