In my ViewController (VC1) I have the following variable:
var orderInfo: Order!
Order is a struct itself like the following:
struct Order {
var orderId: String
var orderReferenceNumber: String
//more variables...
init(
orderId: String,
orderReferenceNumber: String,
){
self.orderId = orderId
self.orderReferenceNumber = orderReferenceNumber
}
init(data: [String: Any]){
orderId = data[DatabaseRef.orderId] as? String ?? ""
orderReferenceNumber = data[DatabaseRef.orderReferenceNumber] as? String ?? ""
}
static func modelToData(order: Order) -> [String: Any] {
let data : [String: Any] = [
DatabaseRef.orderId: order.orderId,
DatabaseRef.orderReferenceNumber: order.orderReferenceNumber,
]
return data
}
}
In VC1, I have a listener that updates its info from Firestore Database (throught addsnapshotslistener). When the variable orderInfo gets updated in VC1 because of a change in the order in the database the listener will update the orderInfo variable in VC1. While the user is in another ViewController (e.g. VC2), I would like to access orderInfo variable with its updated info from VC1. How can I make this happen?
There are numerous of ways of doing that. Lets mention some of them.
You can use NotificationCenter
Example
class VC1: UIViewController {
var orderInfo: Order!
func updateOrder() {
var orderDict = ["orderInfo":orderInfo]
NotificationCenter.default.post(name: NSNotification.Name(rawValue: "orderInfoUpdated"), object: nil, userInfo: orderDict)
}
}
// The receiving end
class VC2: UIViewController {
var orderInfo: Order!
override func viewDidLoad() {
super.viewDidLoad()
NotificationCenter.default.addObserver(self, selector: #selector(doSomething(_: )), name: NSNotification.Name(rawValue: "orderInfoUpdated"), object: nil)
}
func doSomething(_ notification: NSNotification) {
if let orderInfo = notification.userInfo?["orderInfo"] as? Order {
// Do something
}
}
}
You can create an "app state" service where you use the singleton
pattern making the user info accessible in all the views
Example:
class AppState {
static let shared = AppState()
var orderInfo: Order!
...
}
On your ViewController
class ViewController: UIViewController {
func doSomeWork() {
print(AppState.shared.orderInfo)
}
}
You can make it global (Not Recommended)
Related
I've passed to my complicationDescriptors a userInfo dictionary that includes the names of my complications so I can be notified of which complication the user tapped on and launch them to that View. I'm using the new #App and #WKExtensionDelegateAdaptor for other reasons, so I have access to handleUserActivity in my extensionDelegate and can unpack the source of the complication tap, but how do I launch them to a specific view in SwiftUI? handleUserActivity seems to be set up to work with WKInterfaceControllers?
class ExtensionDelegate: NSObject, WKExtensionDelegate {
let defaults = UserDefaults.standard
func applicationDidFinishLaunching() {
//print("ApplicationDidFinishLanching called")
scheduleNextReload()
}
func applicationWillResignActive() {
//print("applicationWillResignActive called")
}
func handleUserActivity(_ userInfo: [AnyHashable : Any]?) {
if let complication = userInfo?[TrackerConstants.complicationUserTappedKey] as? String {
if complication == TrackerConstants.recoveryDescriptorKey {
//What now?
} else if complication == TrackerConstants.exertionDescriptorKey {
//What now?
}
}
}
I managed to update my view according to the tapped complication userInfo by using notifications, inspired by this answer.
First declare a notification name:
extension Notification.Name {
static let complicationTapped = Notification.Name("complicationTapped")
}
In your ExtensionDelegate:
func handleUserActivity(_ userInfo: [AnyHashable : Any]?) {
if let complication = userInfo?[TrackerConstants.complicationUserTappedKey] as? String {
NotificationCenter.default.post(
name: Notification.Name.complicationTapped,
object: complication
)
}
}
Finally in your view:
struct ContentView: View {
#State private var activeComplication: String? = nil
var body: some View {
NavigationView { // or TabView, etc
// Your content with NavigationLinks
}
.onReceive(NotificationCenter.default.publisher(
for: Notification.Name.complicationTapped
)) { output in
self.activeComplication = output.object as? String
}
}
}
For more information on how to activate a view from here, see Programmatic navigation in SwiftUI
I have Outlet of UITextField in the main VC and I want to access its text from another class... for more clarification please see my code below:
class ProductManagement : UIViewController, UITextFieldDelegate{
#IBOutlet weak var ProductName: UITextField!
}
and I want to read the text in below class
import Firebase
import FirebaseStorage
class XUpload {
static func UploadImage(Image : UIImage, Completion : #escaping (_ url : String)->()) {
guard let imageData = Image.pngData() else { return }
let storage = Storage.storage().reference()
let pathRef = storage.child("Images/Products")
let imageRef = pathRef.child( // I want the product name to be written here! )
imageRef.putData(imageData, metadata: nil) { (meta, error) in
imageRef.downloadURL { (url, error) in
print (url as Any)
}
}
}
}
I tried to create a custom protocol to delegate the UITextField but the problem is I couldn't conform it inside XUpload class !!
Please someone write for me how is my code should be because I'm beginner and new to Swift language.
Thank you in advance.
EDIT:
Elia Answer applied below:
ProductManagement Class + Extension
class ProductManagement : UIViewController, UITextFieldDelegate{
override func viewDidLoad() {
super.viewDidLoad()
self.ProductName.delegate = self
}
#IBOutlet weak var ProductName: UITextField!
#objc private func textFieldDidChange(_ sender: UITextField) {
NotificationCenter.default.post(name: .PnameInputText, object: nil, userInfo: ["text": sender.text!])
}
}
extension Notification.Name {
public static var PnameInputText = Notification.Name("PnameInputText")
}
XUpload Class
import Firebase
import FirebaseStorage
class XUpload {
private init() {
NotificationCenter.default.addObserver(self, selector: #selector(handle(_:)), name: .PnameInputText, object: nil)
}
public static var shared = XUpload()
var textFieldText : String = "" {
didSet {print("updated value > ", textFieldText)}
}
#objc private func handle(_ sender: Notification) {
if let userInfo = sender.userInfo as NSDictionary?, let text = userInfo["text"] as? String {
textFieldText = text
}
}
static func UploadImage(Image : UIImage, Completion : #escaping (_ url : String)->()) {
guard let imageData = Image.pngData() else { return }
let storage = Storage.storage().reference()
let pathRef = storage.child("Images/Products")
let imageRef = pathRef.child("img_"+shared.textFieldText)
print("var of textFieldText value: " + shared.textFieldText) //print nothing... empty value!!
imageRef.putData(imageData, metadata: nil) { (meta, error) in
imageRef.downloadURL { (url, error) in
print ("Image uploaded to this link >> " + url!.description)
guard let str = url?.absoluteString else { return }
Completion (str)
}
}
}
}
extension UIImage {
func upload(completion : #escaping (_ url : String) ->()) {
XUpload.UploadImage(Image: self) { (ImageURL) in completion (ImageURL)
}
}
}
As you can see there is no value given to var textFieldText by the Notification Center! why??
class ProductManagement : UIViewController, UITextFieldDelegate{
var productInputText: String = ""
#IBOutlet weak var ProductName: UITextField!
override func viewDidLoad() {
super.viewDidLoad()
ProductName.addTarget(self, action: #selector(textFieldDidChange), for: .editingChanged)
}
#objc private func textFieldDidChange(_ sender: UITextField) {
productInputText = sender.text ?? ""
}
}
This will store your input text into a variable basically with listen edit changes.
And if I get not wrong, you use UploadImage within ProductManagement class. Add a function property to UploadImage as below
class XUpload {
static func UploadImage(Image : UIImage, productName: String, Completion : #escaping (_ url : String)->()) {
guard let imageData = Image.pngData() else { return }
let storage = Storage.storage().reference()
let pathRef = storage.child("Images/Products")
let imageRef = pathRef.child( // I want the product name to be written here! )
imageRef.putData(imageData, metadata: nil) { (meta, error) in
imageRef.downloadURL { (url, error) in
print (url as Any)
}
}
}
}
and call it in ProductManagement class like below.
XUpload.UploadImage(image: myImage, productName: productInputText, Completion: {
}
EDIT:
After getting your comment, I decided the best way do it is using Notification, you use UITextField in ProductManagement class so there is no need to handle delegate method of them in XUpload
Describe notification name
extension Notification.Name {
public static var TextChange = Notification.Name("TextChange")
}
In ProductManagement, textDidChange method post text to Notification
#objc private func textFieldDidChange(_ sender: UITextField) {
NotificationCenter.default.post(name: .TextChange, object: nil, userInfo: ["text": sender.text])
}
I convert your XUpload class to a Singleton class.
class XUpload {
private init() {
NotificationCenter.default.addObserver(self, selector: #selector(handle(_:)), name: .TextChange, object: nil)
}
public static var Shared = XUpload()
#objc private func handle(_ sender: Notification) {
if let userInfo = sender.userInfo as NSDictionary?, let text = userInfo["text"] as? String {
textFieldText = text
}
}
var textFieldText: String = "" {
didSet {
print("updated value > " , textFieldText)
}
}
static func uploadImage() {
// use updated textfield text with textFieldText
}
}
Then store a variable in ProductManagement class as a singleton object and it wil work for you. The text in textfield updated every changes in XUpload class.
class ProductManagement : UIViewController, UITextFieldDelegate{
var staticVariable = XUpload.Shared
}
I have a usermodel that checks the backend if the email exists - then I drill back into a viewcontroller and set a boolean value that should trigger a function run. However the value is unchanged and I am trying to change this value from the usermodel but it is not accessible. I understand why it does not work.. but do not know how to resolve the issue.
static func sendEmailWithResetLink(email: String) {
let params : Parameters = [
PARAM_EMAIL : email
]
request(URL_RESET_PASSWORD as String, method: .post, parameters: params, headers: nil).responseJSON {
(response: DataResponse<Any>) in
hideProgress()
print("this is response \(response)")
switch(response.result)
{
case .success(_):
print("it did not fail")
let passwordResetVC = PasswordResetViewController()
passwordResetVC.hasFailed = false
break
case .failure(_):
print("it failed")
let passwordResetVC = PasswordResetViewController()
//here boolean is set that I am trying to access in viewcontroller
passwordResetVC.hasFailed = true
break
}
}
}
Here's what I would suggest. You probably have some of these in place already:
Create an PasswordResetViewController object has an #IBAction func resetButtonClicked triggered by a button or whatever, which kicks off the password reset process.
Create a UserManager class. This class is responsible for all profile management activies in your app. Among other things, it has the ability to reset user passwords. This UserManager would probably be a singleton, that' sprobably good enough for now.
Create a new UserManagerDelegate protocol. Add to it all capabilities that are required by the UserManager to inform them of whatever happened. For example: var passwordResetHasFailed: Bool { get set }.
Extend your PasswordResetViewController conform to this protocol.
Your VC gets a reference to the singleton UserManager object, stores it in an instance variable, and uses that to access the shared object from then on.
Make your PasswordResetViewController register itself as the delegate to the user manager, with userManager.delegate = self
The #IBAction func resetButtonClicked will just call userManager.resetPassword()
Your UserManager does whatever it needs to do to reset the user's password.
When it's done, it'll call self.delegate?.passwordResetHasFailed = true/false.
Since your PasswordResetViewController registered itself as the delegate of the UserManager, when the operation is done, its passwordResetHasFailed property will be changed, giving it a chance to respond (by updating some UI or whatever).
There are some limitations to this approach, but it's a decent way to get started. Some thing to note:
This lets you unit test your PasswordResetViewController. You can create a MockUserManager, and set tesPasswordResetViewController.userManager = MockUserManager(), allowing you to separate out the user manager, and test PasswordResetViewController in isolation.
You'll run into issues if you need multiple objects to subscribe to receive delegate call backs (since there can only be 1 delegate object). At that point, you can switch to using something like Promises, RxSwift or Combine. But that's a problem for a later time, and the migration would be easy.
Going off of #Alexander - Reinstate Monica and what I assume what the code to look like to approach your problem.
Using MVC:
In Models folder (data/ logic part)
public class User {
private var name: String!
private var userEmail: String!
public var hasFailed: Bool?
init() {
name = ""
userEmail = ""
hasFailed = nil
}
public func setName(name: String) { self.name = name }
public func getName() -> String { return name }
public func setEmail(email: String) { userEmail = email }
public func getEmail() ->String { return userEmail }
public static func sendEmailWithRestLing(email: String) {
// your other code
switch response.result {
case .success(_):
//your code
hasFailed = false
break
case .failuare(_):
// your code
hasFailed = true
break
}
}
}
User Manager class applying singleton design
final class UserManager {
private var user = User()
static let instance = UserManager()
private init(){}
public func userName(name: String) {
if (name.count > 3) {
user.setName(name: name)
}
else { print("user name is too short") }
}
public func userEmail(email: String) {
if (email.count > 3) {
user.setEmail(email: email)
}
else { print("user email is too short") }
}
public func getUserName() -> String {
let name = user.getName()
if (name.isEmpty) { return "user name is Empty" }
return name
}
public func getUserEmail() -> String {
let email = user.getEmail()
if (email.isEmpty) { return "user email is Empty" }
return email
}
public func doKatieTask(link: String) -> Int {
guard let myValue = user.hasFailed else {
return -1
}
if (myValue) { return 1}
return 0
}
}
So, Now in the Controllers folder and since we a one-to-one relation we will use delegate design pattern. If had had one-to-many with the view controller. Use observers.
class ViewController: UIViewController {
#IBOutlet weak var nameTextField: UITextField!
#IBOutlet weak var emailTextField: UITextField!
var _hasFail: Bool!
override func viewDidLoad() {
super.viewDidLoad()
// Do any additional setup after loading the view.
}
#IBAction func doTask() {
UserManager.instance.userName(name: nameTextField.text!)
UserManager.instance.userEmail(email: emailTextField.text!)
switch UserManager.instance.doKatieTask(link: emailTextField.text!) {
case 0:
_hasFail = false
break
case 1:
_hasFail = true
break
default:
print("hasFailed is nil")
break
}
if let vc = storyboard?.instantiateViewController(identifier: "passwordVC") as? PasswordResetViewController {
vc.modalPresentationStyle = .fullScreen
vc.delegate = self
self.present(vc, animated: true, completion: nil)
}
}
}
extension ViewController: KatieDelegate {
var hasFailed: Bool {
get {
return _hasFail
}
set {
_hasFail = newValue
}
}
}
In PasswordReset UIViewController
protocol KatieDelegate {
var hasFailed: Bool { get set }
}
class PasswordResetViewController: UIViewController {
#IBOutlet weak var nameLabel: UILabel!
#IBOutlet weak var emailLabel: UILabel!
var delegate: KatieDelegate?
override func viewDidLoad() {
super.viewDidLoad()
nameLabel.text = UserManger.instance.getUserName()
emailLabel.text = UserManger.instance.getUserEmail()
if let delegate = delegate {
print("The value for has failed is: .....\(delegate.hasFailed)!")
}
else { print("error with delegate") }
}
}
I just started to use Swift/firebase, sorry for my noobiness. I am writing data into firebase database using childbyautoid. I want to access the last key/id in another class.
let postName = Database.database().reference().child("Event").childByAutoId()
let postNameObject = [
"EventName": NameTextField.text,
"timestamp": [".sv":"timestamp"],
"userID": Auth.auth().currentUser!.uid
] as [String:Any]
postName.setValue(postNameObject, withCompletionBlock: { error, ref in
if error == nil {
self.dismiss(animated: true, completion: nil)
} else {
}
})
let childautoID = postName.key
I want to be able to call childautoID in another class our find another way to update this node.
You could maybe make a singleton class for managing Firebase methods. I do something similar whenever building apps with Firebase. This lets you reference values and use methods related to Firebase globally, across multiple classes. Before I adopted this method, I found myself rewriting the same code for uploading objects to firebase. A singleton will let you create reusable code, including storage of a "last key" set in this global class.
class FirebaseManager {
//You've probably seen something similar to this "shared" in other Apple frameworks
//Maybe URLSession.shared or FileManager.default or UserDefaults.standard or SKPaymentQueue.default() or UIApplication.shared
static var shared = FirebaseManager()
func createEvent(name: String, timeStamp: [String:String], uid: String) {
let postNameObject = [
"EventName": name,
"timestamp": timeStamp,
"userID": uid
] as [String:Any]
postName.setValue(postNameObject, withCompletionBlock: { error, ref in
if error == nil {
self.dismiss(animated: true, completion: nil)
} else {
//Do something
}
})
let childautoID = postName.key
//Whatever else you need to do in the function below here...
}
}
Usage:
class SomeViewController: UIViewController {
#IBOutlet var nameTextField: UITextField!
//Some code...
#IBAction func createEventButtonPressed(_ sender: Any) {
FirebaseManager.shared.createEvent(name: nameTextField.text, timeStamp: [".sv":"timestamp"], uid: Auth.auth().currentUser!.uid)
}
//Some more code...
}
Similarly, you could add a value called lastKey of type String in our FirebaseManager class. Note the variable we add to the top of our FirebaseManager class:
class FirebaseManager {
var lastKey: String!
static var shared = FirebaseManager()
func createEvent(name: String, timeStamp: [String:String], uid: String) {
let postNameObject = [
"EventName": name,
"timestamp": timeStamp,
"userID": uid
] as [String:Any]
postName.setValue(postNameObject, withCompletionBlock: { error, ref in
if error == nil {
self.dismiss(animated: true, completion: nil)
} else {
//Do something
}
})
let childautoID = postName.key
//Whatever else you need to do in the function below here...
}
}
Similarly, we can set this value in one view controller:
class ViewControllerA: UIViewController {
override func viewDidLoad() {
super.viewDidLoad()
FirebaseManager.shared.lastKey = "aBcDeFg9876543210"
}
}
And grab this value in another view controller that loads following the previous view controller:
class ViewControllerB: UIViewController {
override func viewDidLoad() {
super.viewDidLoad()
print(FirebaseManager.shared.lastKey)
}
}
Prints: aBcDeFg9876543210
This is the beauty of the static keyword. You can learn more about creating singleton classes here: https://cocoacasts.com/what-is-a-singleton-and-how-to-create-one-in-swift
I'm trying to use a Struct to pass some variables that I get from a Facebook Graph Request such as email, name, gender, etc.
I've created the Struct ('fbDemographics') and the variables in 'ViewController' but I get an error when I try to call the struct and one of the variables in 'SecondViewController' (Type 'ViewController' has no member 'fbDemographics'). I've never used struct before so a bit baffled why I am getting this error. Thanks for any thoughts. The code for both view controllers is below:
class ViewController: UIViewController, FBSDKLoginButtonDelegate {
override func viewDidLoad() {
super.viewDidLoad()
struct fbDemographics {
static var relationship_status: String?
static var gender: String?
static var user_education_history: String?
static var user_location: String?
static var email: String?
static var name: String?
}
FBSDKGraphRequest(graphPath: "me", parameters: ["fields": "id, name, relationship_status, gender, user_location, user_education_history, email"]).start(completionHandler: { (connection, result, error) -> Void in
if (error == nil){
//let fbDetails = result as! NSDictionary
//print(fbDetails)
if let userDataDict = result as? NSDictionary {
fbDemographics.gender = userDataDict["gender"] as? String
fbDemographics.email = userDataDict["email"] as? String
fbDemographics.name = userDataDict["name"] as? String
fbDemographics.user_location = userDataDict["user_location"] as? String
fbDemographics.user_education_history = userDataDict["user_education_history"] as? String
fbDemographics.relationship_status = userDataDict["relationship_status"] as? String
let myEducation = fbDemographics.user_education_history
let myEmail = fbDemographics.email
let myGender = fbDemographics.gender
let myName = fbDemographics.name
let myStatus = fbDemographics.relationship_status
let myLocation = fbDemographics.user_location
self.performSegue(withIdentifier: "LoginToHome", sender: (Any).self)
}
}
SECOND VIEW CONTROLLER
class SecondViewController: UIViewController {
#IBAction func verticalSliderChanged(_ sender: UISlider) {
let currentValue = String(sender.value);
sliderLabel.text = "\(currentValue)"
func viewDidLoad() {
super.viewDidLoad()
***ViewController.fbDemographics.myEmail***
}
}
The problem is that you've defined your struct inside viewDidLoad. So the scope is limited to that method. Move it out of viewDidLoad, but still in ViewController, and you should be able to access it from the SecondViewController. Obviously, you'll have to fix that reference to myEmail, too, because it's called email. Also, in your SecondViewController you should pull viewDidLoad implementation out of the verticalSliderChanged method; the viewDidLoad should be a top-level instance method of SecondViewController, not defined inside another method.
There are deeper problems here, though. Rather than using struct with static variables, you really should make those simple instance variables, create an instance of your FbDemographics type (note, start struct types with uppercase letter), and then pass this instance in prepare(for:sender:).
For example, the right way to pass data would be to:
eliminate static variables;
give your struct a name that starts with uppercase letter;
create instance of your struct; and
pass this instance to the destination view controller in prepare(for:sender:).
E.g.
struct FbDemographics {
var relationshipStatus: String?
var gender: String?
var userEducationHistory: String?
var userLocation: String?
var email: String?
var name: String?
}
class ViewController: UIViewController {
var demographics: FbDemographics?
override func viewDidLoad() {
super.viewDidLoad()
performRequest() // I actually don't think you should be initiating this in `viewDidLoad` ... perhaps in `viewDidAppear`
}
override func prepare(for segue: UIStoryboardSegue, sender: Any?) {
if let destination = segue.destination as? SecondViewController {
destination.demographics = demographics
}
}
func performRequest() {
FBSDKGraphRequest(graphPath: "me", parameters: ["fields": "id, name, relationship_status, gender, user_location, user_education_history, email"]).start { connection, result, error in
guard let userDataDict = result as? NSDictionary, error == nil else {
print("\(error)")
return
}
self.demographics = FbDemographics(
relationshipStatus: userDataDict["relationship_status"] as? String,
gender: userDataDict["gender"] as? String,
userEducationHistory: userDataDict["user_education_history"] as? String,
userLocation: userDataDict["user_location"] as? String,
email: userDataDict["email"] as? String,
name: userDataDict["name"] as? String
)
self.performSegue(withIdentifier: "LoginToHome", sender: self)
}
}
}
And then SecondViewController could:
class SecondViewController: UIViewController {
var demographics: FbDemographics!
override func viewDidLoad() {
super.viewDidLoad()
let value = demographics.email // this should work fine here
}
}