azamsharp

import Foundation
import UIKit

class BindingTextField : UITextField {
    
    var textChanged :(String) -> () = { _ in }
    
    func bind(callback :@escaping (String) -> ()) {
        
        self.textChanged = callback

azamsharp

  @IBOutlet weak var titleTextField :BindingTextField! {
        didSet {
            titleTextField.bind { self.viewModel.title.value = $0 }
        }
    }
    @IBOutlet weak var descriptionTextField :BindingTextField! {
        didSet {
            descriptionTextField.bind { self.viewModel.description.value = $0 }
        }
    }

azamsharp

struct ChangePasswordViewModel {
    
    var newPassword = Dynamic<String>("")
    var confirmPassword = Dynamic<String>("")
    
}

azamsharp

class ChangePasswordTableViewController : UITableViewController {
    
    private var viewModel :ChangePasswordViewModel = ChangePasswordViewModel() 
    
    @IBOutlet weak var newPasswordTextField :BindingTextField! {
        didSet {
            self.newPasswordTextField.bind { self.viewModel.newPassword.value = $0 }
        }
    }
    @IBOutlet weak var confirmPasswordTextField :BindingTextField! {

azamsharp

    @IBAction func save() {
        
        var errors = [String]()
        
        if (viewModel.newPassword.value?.count)! < 8 {
            errors.append("Password should be at least 8 characters long")
        }
        if viewModel.newPassword.value != viewModel.confirmPassword.value {
            errors.append("Password is not matching")
        }

azamsharp

struct BrokenRule {
    
    var propertyName :String
    var message :String
}

protocol ViewModel {
    
    var brokenRules :[BrokenRule] { get set}
    var isValid :Bool { mutating get }

azamsharp

struct ChangePasswordViewModel : ViewModel {
    
    var brokenRules: [BrokenRule] = [BrokenRule]() 
    
    var newPassword = Dynamic<String>("")
    var confirmPassword = Dynamic<String>("")
    
    var isValid :Bool {
        mutating get {
            self.brokenRules = [BrokenRule]()

azamsharp

 
    @IBAction func save() {
        
        if self.viewModel.isValid {
            // update the password
            print("update the user's password")
        } else {
            // show errors
            print(self.viewModel.brokenRules)
        }

azamsharp

struct ChangePasswordViewModel : ViewModel {
    
    
    @Required(message: "New Password is required", minLength:8)
    var newPassword = Dynamic<String>("")
    @Required(message: "Confirm Password is required", minLength: 8)
    var confirmPassword = Dynamic<String>("")

azamsharp

class ArticleListViewModel {
    
    private(set) var webservice :Webservice!
    
    var title :String? = "Articles"
    var articles :[ArticleViewModel] = [ArticleViewModel]() 
    
    init(articles :[ArticleViewModel]) {
        self.articles = articles
    }