ARRAY
Declare an array
// Declare an array
var Countries = ["England", "Ireland", "Scotland", "Wales"]
// Declare an array of given size
var myArray = Array(repeating: 0, count: 4)
var myArray = Array(repeating: "", count: 8)
var someInts = [Int](count: 3, repeatedValue: 0
Declare an empty array
var Countries = [String]()
Access an array value
print(Countries[2]) // print "Ireland"
Add an element to an array
// Insertion at the end of an array
countries.append("Brazil")
// Insertion at a specific position in an array
countries.insert("Brazil", at: 2)
Remove an element from an array
// Remove an element at a specific position in an array
countries.remove(at: 2)
Declare multidimensional array
// Declare multidimensional array
var groups = [[String]]()
// Create three string arrays
var groupA = ["England", "Ireland", "Scotland", "Wales"]
var groupB = ["Canada", "Mexico", "United States"]
var groupC = ["China", "Japan", "South Korea"]
// Add them all to the multidimensional array names "groups"
groups.append(groupA)
groups.append(groupB)
groups.append(groupC)
// Other method (create 3x5 multidimensional array with digits 0):
var cinema = Array(repeating: Array(repeating: 0, count: 3), count: 5)
Loop through an array
// Classic loop:
for country in Countries {
print("\(country.value) is from \(country.key)")
}
// Reverse order loop:
for ship in ships.reversed() {
print("\(country.value) is from \(country.key)")
}
// Loop with index:
for (index, country) in Countries.enumerated() {
print("\(index):\(country)")
}
Get Index of specific element in array
if let index = array.firstIndex(of: e) {
//index has the position of first match
} else {
//element is not present in the array
}
Get number of elements in array
countries.count
Sort array
// Sort array
Countries.sort()
// Sort struct object by one criterium
users.sort { $0.firstName < $1.firstName }
// Sort struc object by two criteria
users.sort { ($0.lastName, $0.firstName) < ($1.lastName, $1.firstName) }
Check if array is empty
if countries.isEmpty {
print("The array is empty")
}
Call a function for each element of an array
countries.forEach {
print($0) // England, Ireland, Scotland, Wales
}
Search an element in an array
if countries.contains("England") {
print("The array contains England")
}
Remove duplicate
extension Array where Element: Hashable {
// function which returns an array with duplicates removed
func removingDuplicates() -> [Element] {
var addedDict = [Element: Bool]()
return filter {
addedDict.updateValue(true, forKey: $0) == nil
}
}
// function which removes the duplicates in the array
mutating func removeDuplicates() {
self = self.removingDuplicates()
}
}
// Usage:
let numbers = [1, 5, 3, 4, 5, 1, 3]
let unique = numbers.removingDuplicates()
numbers.removeDuplicates()
DICTIONNARY
Declare a dictionnary
var capitals = ["Nepal": "Kathmandu", "Italy": "Rome", "England": "London"]
var numbers = [1: "One", 2: "Two", 3: "Three"]
Declare an empty dictionnary
var capitals = [Int: String]()
Access an element of a dictionnary
print(capitalCity["Nepal"])
Add an element to a dictionnary
capitalCity["Japan"] = "Tokyo"
TUPPLE
Declare a tupple
var product = ("MacBook", 1090)
Access an element of a tupple
// access the first element
product.0
// access second element
product.1
LOOPS | Code repetition
For (when the number of iterations is known)
// Loop with a range iteration
for i in 1...3 {
print(i) // 1, 2, 3
}
// Loop in an array
let countries = ["France", "Spain", "Germany"]
for country in countries {
print(country) // France, Spain, Germany
}
// Reverse order loop in an array
for country in countries.reversed() {
print("\(country)") // Germany, Spain, France
}
// Loop in an array with index
for (index, country) in countries.enumerated() {
print("\(index):\(country)")
}
// Exclude "Spain"
for country in countries where country != "Spain"{
print(country) // France, Germany
}
// Loop with a stride iteration
for i in stride(from: 1, to: 10, by: 2) {
print(i) // 1, 3, 5, 7, 9
}
While (when the number of iterations is unknown)
var i = 1, n = 5
while (i <= n) { // the code repeat until the condition is met
print(i) // 1, 2, 3, 4, 5
i = i + 1
}
Repeat...While (when the number of iterations is unknown)
var i = 1, n = 5
repeat {
print(i)
i = i + 1
} while (i <= n) // the code repeats until the condition is met
Break statement
// The break statement is used to terminate a loop repetition
for i in 1...5 {
if i == 3 {
break
}
print(i)
}
Continue statement
// The continue statement is used to skip the current iteration of the loop
for i in 1...3 {
if i == 2 {
continue
}
print(i) // 1, 3
}
CONDITIONS
If statement
if (number == 2) {
print("Number is 2")
} else if (number == 3){
print("Number is 3")
} else {
print("Number is not 2")
}
Ternary operator (If...Else statement equivalent)
let result = (number > 0) ? "Positive Number" : "Negative Number"
Comparison operators
== : Equal to
!= : Not equal to
> : Greater than
< : Less than
>= : Greater than or Equal to
<= : Less than or Equal to
Logical operators
&& : Logical AND
|| : Logical OR
! : Logical NOT
FUNCTIONS
Function
// Declare the function
func hello() {
print("Hello World!")
}
// Call the function
hello() // Hello World!
Function with parameters
// Declare the function
func hello(name: String) {
print("Hello \(name)!")
}
// Call the function
hello("Mike") // Hello Mike!
Function with default value as paramater
// Declare the function
func hello(name: String = "Peter") {
print("Hello \(name)!")
}
// Call the function
hello() // Hello Peter!
hello("Mike") // Hello Mike!
Function returning a value
// Declare the function
func total(A: Int, B: Int) -> Int {
let Sum = A + B
return Sum
}
// Call the function
total(A: 2, B: 3) // 5
Throwing functions
// Declare the function
// Define an enum that describes the errors we can throw (based on Swift’s existing Error type)
enum PasswordError: Error {
case obvious
}
func checkPassword(_ password: String) throws -> Bool {
if password == "password" {
throw PasswordError.obvious
}
return true
}
// Call the function
do {
// if error is thrown through the execution of the do block, execution immediately jumps to the catch block
// if no error is thrown, the remaining statements in the do statement are executed and the value true is return by the function
try checkPassword("password")
print("That password is good!")
} catch {
print("You can't use that password.")
}
STRUC
Declare a Struct
struct Game {
let idGame : Int
let teamA : String
let teamB : String
var scoreTeamA : Int
var scoreTeamB : Int
}
struct Person {
var name = "Jean"
var age = 0
}
Create a Struct
var games : [Game] = [
Game(idGame: 1, teamA: "France", teamB: "Italy", scoreTeamA: 2, scoreTeamB: 0),
Game(idGame: 2, teamA: "Portugal", teamB: "Germany", scoreTeamA: 0, scoreTeamB: 0),
Game(idGame: 3, teamA: "Brazil", teamB: "Spain", scoreTeamA: 1, scoreTeamB: 2),
]
var IndividualA = Person()
Access an element of a Struct
print(games[1].teamA) // Portugal
games[1].scoreA = 2 // Set the score of team A to 2
IndividualA.name = "Mike" // Change the name of the individual A
Function in a Struct
struct Car {
var numberA : Int
var numberB : Int
func displaySumNumbers() -> Int{
print(numberA + numberB)
}
func sumNumbers() -> Int{
return numberA + numberB
}
}
let carX = Car(numberA: 2, numberB: 4)
carX.displaySumNumber() // 6
sumX = sumNumbers()
TIME
Get current date and time
let today = Date()
let hours = (Calendar.current.component(.hour, from: today))
let minutes = (Calendar.current.component(.minute, from: today))
let seconds = (Calendar.current.component(.second, from: today))
Format current time into a custom date format
// Set given date
let inputDate = "12.10.2018"
// Create date formatter
let dateFormatter = DateFormatter()
// Set date format
dateFormatter.dateFormat = "YY/MM/dd"
// Convert Date to String (28/11/22)
dateFormatter.string(from: inputDate)
Get information about the user timezone
// Get seconds from GMT (7200)
var secondsFromGMT: Int { return TimeZone.current.secondsFromGMT() }
// Get timezone abbreviation (GMT-2)
var localTimeZoneAbbreviation: String { return TimeZone.current.abbreviation() ?? "" }
// Get timezone identifier (America/Sao_Paulo)
var localTimeZoneIdentifier: String { return TimeZone.current.identifier }
Convert timezones
// Get current date
let TodayDate = Date()
// Set date formatters
let formatterHourGMT = DateFormatter()
formatterHourGMT.timeZone = TimeZone(abbreviation: "GMT")
formatterHourGMT.dateFormat = "HH"
formatterHourGMT.locale = Locale(identifier: "es_ES") // "en_US", "fr_FR"
let formatterInLocal = DateFormatter()
formatterInLocal.timeZone = .current
formatterInLocal.dateFormat = "HH"
// Get formatted date
CurrentHourInGMTstring = formatterHourGMT.string(from: TodayDate)
CurrentHourInGMTint = Int(CurrentHourGMTstring)!
CurrentHourLocalstring = formatterInLocal.string(from: TodayDate)
CurrentHourLocalint = Int(CurrentHourLocalstring)!
Custom date formatting patterns
// Hour
h : 4 (12h format)
H : 16 (24h format)
hh : 04 (12h format)
HH : 16 (24h format)
a : PM (AM/PM)
m : 5
mm : 05
s : 8
ss : 08
zzz : CST
zzzz: Central Standard Time
Z : -0400
ZZZZZ: -04:00
// Day
d : 5
dd : 05
E : Wed
EEEE : Wednesday
// Month
M : 9
MM : 09
MMM : Sep
MMMM : September
MMMMM : S
// Year
y : 2022
yy : 22
yyyy : 2022
// Exemples:
dd.MM.yy : 05.09.22
d.M.yy : 5.9.2022
HH:mm:ss : 18:22:30
MMMM yyyy : September 2022
EEEE, MMM d, yyyy : Wednesday, Sep 15, 2022
MMM d, yyyy : Sep 15, 2022
// Website:
// To play around with different formats and locales to test your format strings
https://nsdateformatter.com
ASYNCHRONOUS FUNCTIONS | Completion handler
An asynchronous function runs on a separate thread, taking as much time as it needs, leaving the main thread running in the meantime. However, sometimes, we need to hold on the completion of an asynchronous function to execute other code. This can be done through the use of completion handlers.
// Declare function A
func verifExistingGrouplD(completion:@escaping(Bool)->Void){
var BoolVar = false
// code to run
completion(BoolVar)
}
// Declare function B (to be run after function A will be completed)
func verifCompletionHandler (value: Bool){
if value {
// code to run
}
}
// Call the functions
verifExistingGroupID(completion: verifCompletionHandler)
ASYNCHRONOUS FUNCTIONS | Try Await
An asynchronous function runs on a separate thread, taking as much time as it needs, leaving the main thread running in the meantime. However, sometimes, we need to hold on the completion of an asynchronous function to execute other code. This can be done through the use of throwing functions and try await.
// Declare a struct for time format
struct TimeData: Codable {
let year: Int
let month: Int
let day: Int
let hour: Int
let minute: Int
}
// Declare the throwing function
static func fetchTimeFromWeb() async throws -> TimeData {
// Define an enum that describes the errors we can throw (based on Swift’s existing Error type)
enum TimeFetcherError: Error {
case invalidURL
case missingData
}
guard let url = URL(string: "https://www.timeapi.io/api/Time/current/zone?timeZone=GMT") else {
throw TimeFetcherError.invalidURL
}
let (data, _) = try await URLSession.shared.data(from: url)
// Parse the JSON data
let decodedData = try JSONDecoder().decode(TimeData.self, from: data)
return decodedData
}
// Call the throwing function
Task {
do {
// if error is thrown through the execution of the do block, execution immediately jumps to the catch block
// if no error is thrown, the remaining statements in the do statement are executed and the value true is return by the function
let currentTimeWeb = try await LiveTime.fetchTimeFromWeb()
// Code to execute
} catch {
print("Request failed with error: \(error)")
}
}
ANIMATION
UIView.animate(withDuration: 0.25, animations: {
// Code to be animated (for instance: .isHidden)
}
CODE EXECUTION ON CHANGE IN TEXFIELD
textfield.addTarget(self, action: #selector(ViewController.textFieldDidChange(_:)), for: .editingChanged)
@objc func textFieldDidChange(_ textField: UITextField) {
// code to execute
}
GET DEVICE HEIGHT AND WIDTH
var bounds = UIScreen.main.bounds
var width = bounds.size.width
var height = bounds.size.height
DELAYED CODE EXECUTION
DispatchQueue.main.asyncAfter(deadline: .now() + 1) {
// code to execute
}
HIDE HOME INDICATOR
// Add the following to the view controller on which you want to hide the home indicator
override var prefersHomeIndicatorAutoHidden: Bool {
return true
}
// To call the function:
setNeedsUpdateOfHomeIndicatorAutoHidden()
MULTISCREEN | Add a new screen
1. Add a new View Controller
2. Create a View Controller cocoa file
3. Link the new ViewController file with the ViewController
SEGUE | Open a new ViewController
1. Create Segue
2. Add the following code to run the segue (go to the destination ViewController)
performSegue(withIdentifier: "GoToResultSegue", sender: self)
How to pass a variable through the segue to the destination View Controller
1. Add a variable to the destination View Controller
class VC_GroupRanking: UIViewController {
var DataFromGroupsVC = "None"
override func viewDidLoad() {
super.viewDidLoad()
}
}
2. Enter this code in the sender View Controller (to be triggered during the segue)
let variableToPass = "salut"
override func prepare(for segue: UIStoryboardSegue, sender: Any?) {
if segue.identifier == "FromGroupsToGroupRanking" {
let destinationVC = segue.destination as! VC_GroupRanking
destinationVC.DataFromGroupsVC = variableToPass
}
}
VIEWCONTROLLER | Remove a ViewController
Introduction
In order to navigate to another View Controller, the new View Controller can be either pushed or presented:
• If presented, the new view controller is presented modally on top of the existing view controller.
• If pushed, the new view controller is pushed through navigation onto the existing navigation stack.
To go back to the previous view controller the new View Controller is dismissed if it was presented modally while we navigate back to the previous controller if it was pushed.
A. Dismiss a view controller presented modally
self.dismiss(animated: false, completion: nil)
B. Dismiss a view controller pushed through navigation
navigationController?.popViewController(animated: true)
C. Dismiss several view controllers pushed through navigation (go to VC_Main)
let vc = self.navigationController?.viewControllers.filter({$0 is VC_Main}).first
self.navigationController?.popToViewController(vc!, animated: true)
D. Dismiss all view controller presented modally as well as all view controllers pushed through navigation
let rootViewController = self.view.window?.rootViewController as? UINavigationController
rootViewController?.setViewControllers([rootViewController!.viewControllers.first!], animated: false)
rootViewController?.dismiss(animated: true, completion: nil)
NAVIGATION BAR | Set up navigation bar in XCode
Click in the menu on Editor: Embed in: Navigation controller
A. Hide navigation bar in View Controller
override func viewWillAppear(_ animated: Bool) {
super.viewWillAppear(animated)
navigationController?.setNavigationBarHidden(true, animated: animated)
}
B. Display navigation bar in View Controller
override func viewWillAppear(_ animated: Bool) {
super.viewWillAppear(animated)
navigationController?.setNavigationBarHidden(false, animated: animated)
}
C. Change colors of navigation bar
override func viewWillAppear(_ animated: Bool) {
super.viewWillAppear(animated)
navigationController?.setNavigationBarHidden(false, animated: animated)
// text color:
navigationController?.navigationBar.tintColor = UIColor.black
// background color:
navigationController?.navigationBar.barTintColor = UIColor.yellow
}
D. Make navigation bar background transparent
override func viewWillAppear(_ animated: Bool) {
super.viewWillAppear(animated)
let appearance = UINavigationBarAppearance()
appearance.configureWithTransparentBackground()
navigationController?.navigationBar.standardAppearance = appearance
}
E. Advanced style customization
// Customize the Right View
let segmentBarItem = UIBarButtonItem(customView: segmentedControl)
navigationItem.rightBarButtonItem = segmentBarItem
// Customize the Title View
self.navigationItem.titleView = segmentedControl
// Modify the Navigation Prompt
navigationItem.prompt = NSLocalizedString("Navigation prompts appear at the top.", comment: "")
// Change the Bar Style
self.navigationController!.navigationBar.barStyle = .black
self.navigationController!.navigationBar.isTranslucent = false
self.navigationController!.navigationBar.titleTextAttributes = [.foregroundColor: UIColor.white]
// Make the navigation bar's title with red text.
let appearance = UINavigationBarAppearance()
appearance.configureWithOpaqueBackground()
appearance.backgroundColor = UIColor.systemRed
appearance.titleTextAttributes = [.foregroundColor: UIColor.lightText] // With a red background, make the title more readable.
navigationItem.standardAppearance = appearance
navigationItem.scrollEdgeAppearance = appearance
navigationItem.compactAppearance = appearance // For iPhone small navigation bar in landscape.
// Make all buttons with green text.
let buttonAppearance = UIBarButtonItemAppearance()
buttonAppearance.normal.titleTextAttributes = [.foregroundColor: UIColor.systemGreen]
navigationItem.standardAppearance?.buttonAppearance = buttonAppearance
navigationItem.compactAppearance?.buttonAppearance = buttonAppearance // For iPhone small navigation bar in landscape.
// Make the done style button with yellow text.
let doneButtonAppearance = UIBarButtonItemAppearance()
doneButtonAppearance.normal.titleTextAttributes = [.foregroundColor: UIColor.systemYellow]
navigationItem.standardAppearance?.doneButtonAppearance = doneButtonAppearance
navigationItem.compactAppearance?.doneButtonAppearance = doneButtonAppearance // For iPhone small navigation bar in landscape.
// Customize the Back Button with an Image
let backButtonBackgroundImage = UIImage(systemName: "list.bullet")
let barAppearance =
UINavigationBar.appearance(whenContainedInInstancesOf: [CustomBackButtonNavController.self])
barAppearance.backIndicatorImage = backButtonBackgroundImage
barAppearance.backIndicatorTransitionMaskImage = backButtonBackgroundImage
let barButtonAppearance =
UIBarButtonItem.appearance(whenContainedInInstancesOf: [CustomBackButtonNavController.self])
barButtonAppearance.setBackButtonTitlePositionAdjustment(UIOffset(horizontal: 0, vertical: -5), for: .default)
let backBarButton = UIBarButtonItem(title: "", style: .plain, target: nil, action: nil)
navigationItem.backBarButtonItem = backBarButton
// Remove the back button
let backBarButton = UIBarButtonItem(title: "", style: .plain, target: nil, action: nil)
navigationItem.backBarButtonItem = backBarButton
TABLEVIEW | Standard Table View
1. Add a Table View Controller
2. Add a Table View Cell and set the identifier for the custom cell
3. Add a new Swift File for the structure to be used as data
struct game {
let idGame : Int
var scoreTeamA : Int
var scoreTeamB : Int
}
In the View Controller code:
4. Add an outlet for the Table View
@IBOutlet weak var TableViewOutlet: UITableView!
5. Add an array of objects related to the custom cells
var game : [game] = [
game(idGame: 1, teamA: "France", teamB: "Italy", scoreTeamA: 2, scoreTeamB: 0),
game(idGame: 2, teamA: "Portugal", teamB: "Germany", scoreTeamA: 0, scoreTeamB: 0),
game(idGame: 3, teamA: "Brazil", teamB: "Spain", scoreTeamA: 1, scoreTeamB: 2),
]
6. Add these extensions below the ViewController class code
extension ViewController : UITableViewDataSource{
func tableView(_ tableView: UITableView, numberOfRowsInSection section: Int) -> Int {
return games.count
}
func tableView(_ tableView: UITableView, cellForRowAt indexPath: IndexPath) -> UITableViewCell {
let cell = tableView.dequeueReusableCell(withIdentifier: "ReusableCell", for: indexPath)
cell.textLabel?.text = games[indexPath.row].teamA
return cell
}
// Optional: Add sections
func numberOfSections(in tableView: UITableView) -> Int {
return 2
}
func tableView(_ tableView: UITableView, titleForHeaderInSection section: Int) -> String? {
switch (section) {
case 0:
return "Semi-finals"
case 1:
return "Final"
default:
return "ERROR"
}
}
}
extension ViewController : UITableViewDelegate{
func tableView(_ tableView: UITableView, didDeselectRowAt indexPath: IndexPath) {
// code to execute if user click on a cell
// print(indexPath.row)
}
}
7. Add the following code in the viewDidLoad function
override func viewDidLoad() {
super.viewDidLoad()
TableViewOutlet.dataSource = self
TableViewOutlet.delegate = self
}
To deselect a row in Table View (Optional)
extension UITableView {
func deselectSelectedRow(animated: Bool)
{
if let indexPathForSelectedRow = self.indexPathForSelectedRow {
self.deselectRow(at: indexPathForSelectedRow, animated: animated)
}
}
}
// Usage:
self.tableView.deselectSelectedRow(animated: true)
Optional: To scroll to a specific cell in Table View
self.TableViewOutlet.scrollToRow(at: IndexPath(row: 5, section: 0), at: .top, animated: true)
Optional: To reload a tableview
DispatchQueue.main.async{
self.TableViewOutlet.reloadData()
}
TABLEVIEW | Table View with custom cells
1. Add a Table View Controller
2. Create a new Coco Touch Class file in the Views Folder (Subclass of a UITableViewCell called CustomCell and tick: "Also create XIB file")
3. Two files are created: CustomCell.swift and CustomCell.xib
4. In CustomTeamCell.xib | Design the custom cell
5. In CustomTeamCell.swift | Add outlets for the elements of the CustomTeamCell.swift file
class CustomGameCell: UITableViewCell {
@IBOutlet weak var TeamALabelOutlet: UILabel!
@IBOutlet weak var TeamBLabelOutlet: UILabel!
@IBOutlet weak var ScoreALabelOutlet: UILabel!
@IBOutlet weak var ScoreBLabelOutlet: UILabel!
override func awakeFromNib() {
super.awakeFromNib()
// Initialization code
}
override func setSelected(_ selected: Bool, animated: Bool) {
super.setSelected(selected, animated: animated)
// Configure the view for the selected state
}
}
6. Add a new Swift File for the structure to be used as data
struct game {
let idGame : Int
var scoreTeamA : Int
var scoreTeamB : Int
}
In the View Controller code:
7. Add an outlet for the Table View
@IBOutlet weak var TableViewOutlet: UITableView!
8. Add an array of objects related to the custom cells
var game : [game] = [
game(idGame: 1, teamA: "France", teamB: "Italy", scoreTeamA: 2, scoreTeamB: 0),
game(idGame: 2, teamA: "Portugal", teamB: "Germany", scoreTeamA: 0, scoreTeamB: 0),
game(idGame: 3, teamA: "Brazil", teamB: "Spain", scoreTeamA: 1, scoreTeamB: 2),
]
9. Add these extensions below the ViewController class code
extension ViewController : UITableViewDataSource{
func tableView(_ tableView: UITableView, numberOfRowsInSection section: Int) -> Int {
return games.count
}
func tableView(_ tableView: UITableView, cellForRowAt indexPath: IndexPath) -> UITableViewCell {
let cell = tableView.dequeueReusableCell(withIdentifier: "IDCustomGameCell", for: indexPath) as! CustomGameCell
cell.OutletCountryA.text = games[indexPath.row].teamA
cell.OutletCountryB.text = games[indexPath.row].teamB
cell.OutletScoreA.text = games[indexPath.row].scoreTeamA
cell.OutletScoreB.text = games[indexPath.row].scoreTeamB
return cell
}
// Optional: Add sections
func numberOfSections(in tableView: UITableView) -> Int {
return 2
}
func tableView(_ tableView: UITableView, titleForHeaderInSection section: Int) -> String? {
switch (section) {
case 0:
return "Semi-finals"
case 1:
return "Final"
default:
return "ERROR"
}
}
}
extension ViewController : UITableViewDelegate{
func tableView(_ tableView: UITableView, didDeselectRowAt indexPath: IndexPath) {
// code to execute if user click on a cell
// print(indexPath.row)
}
}
10. Add the following code in the viewDidLoad function
override func viewDidLoad() {
super.viewDidLoad()
TableViewOutlet.dataSource = self
TableViewOutlet.delegate = self
// CUSTOM CELL:
TableViewOutlet.register(UINib(nibName: "CustomGameCell", bundle: nil), forCellReuseIdentifier: "IDCustomGameCell")
}
To deselect a row in Table View (Optional)
extension UITableView {
func deselectSelectedRow(animated: Bool)
{
if let indexPathForSelectedRow = self.indexPathForSelectedRow {
self.deselectRow(at: indexPathForSelectedRow, animated: animated)
}
}
}
// Usage:
self.tableView.deselectSelectedRow(animated: true)
Optional: To scroll to a specific cell in Table View
self.TableViewOutlet.scrollToRow(at: IndexPath(row: 5, section: 0), at: .top, animated: true)
Optional: To reload a tableview
DispatchQueue.main.async{
self.TableViewOutlet.reloadData()
}
PICKER VIEW
1. Add a Scroll View into the View Controller
In the storyboard, drag a UIPickerView into the View Controller and set the relevant constraints
2. Link the Scroll View to the View Controller class through an outlet
class VC_ViewController: UIViewController {
@IBOutlet weak var picker: UIPickerView!
override func viewDidLoad() {
super.viewDidLoad()
// ...
}
}
3. Add this code to the ViewDidLoad section
override func viewDidLoad() {
super.viewDidLoad()
picker.delegate = self
picker.dataSource = self
}
4. Prepare the data for the Picker View
class VC_ViewController: UIViewController {
@IBOutlet weak var picker: UIPickerView!
var pickerData: [String] = [String]()
override func viewDidLoad() {
super.viewDidLoad()
picker.delegate = self
picker.dataSource = self
pickerData = ["Item 1", "Item 2", "Item 3", "Item 4", "Item 5", "Item 6"]
}
}
5. Add these extensions to connect the data to the Picker View
extension VC_ViewController : UIPickerViewDataSource{
// Number of columns of data
func numberOfComponents(in pickerView: UIPickerView) -> Int {
return 1
}
// The number of rows of data
func pickerView(_ pickerView: UIPickerView, numberOfRowsInComponent component: Int) -> Int {
pickerData.count
}
// The data to return for the row and component (column) that's being passed in
func pickerView(_ pickerView: UIPickerView, titleForRow row: Int, forComponent component: Int) -> String? {
return pickerData[row]
}
}
6. Add this extension to get the value of the selected item in the PickerView
extension VC_ViewController: UIPickerViewDelegate{
// Capture the picker view selection
func pickerView(_ pickerView: UIPickerView, didSelectRow row: Int, inComponent component: Int) {
// This method is triggered whenever the user makes a change to the picker selection (the initial picker selection is thus not captured)
// The parameter named row and component represents what was selected
Score = row
}
}
6bis. Case of 2 Picker Views
extension VC_ViewController: UIPickerViewDelegate{
// Capture the picker view selection
func pickerView(_ pickerView: UIPickerView, didSelectRow row: Int, inComponent component: Int) {
if pickerView.tag == 1 {
ScoreA = row
}
if pickerView.tag == 2{
ScoreB = row
}
}
}
Optional: Change font size and color of the Picker View elements
extension VC_ViewController: UIPickerViewDelegate{
// set the font and size of the picker text
func pickerView(_ pickerView: UIPickerView, viewForRow row: Int, forComponent component: Int, reusing view: UIView?) -> UIView {
var pickerLabel: UILabel? = (view as? UILabel)
if pickerLabel == nil {
pickerLabel = UILabel()
pickerLabel?.font = UIFont(name: "Kohinoor Telugu Medium", size: 32)
pickerLabel?.textAlignment = .center
}
pickerLabel?.text = "\(pickerNumbers[row])"
pickerLabel?.textColor = #colorLiteral(red: 0.6629547477, green: 0.5059737563, blue: 0.5765327811, alpha: 1)
return pickerLabel!
}
// set the height of the pickerview rows
func pickerView(_ pickerView: UIPickerView, rowHeightForComponent component: Int) -> CGFloat
{
return 60
}
}
Optional: Programmatically select a row
picker.selectRow(3, inComponent: 0, animated: true)
SCROLL VIEW
1. Add a Scroll View into the View Controller
In the storyboard, drag a UIScrollView into the View Controller and set the relevant constraints (for instance: 0, 0, 0, 0 to the safe area). Also, pin the scoll view to the edges of the safe area. After setting constraints, red lines will appear because the scrollable content size of the scroll view hasn't been set yet.
2. Put a View inside the Scroll View
In the storyboard, drag a UIView inside the scroll view and name it Content View
To set the constraints of the Content View, drag the Content View to the Content Layout Guide meanwhile pressing the control key. In the constraints selection popup, hold shift to select multiple constraints and select the leading, top, trailing, bottom constraints. After creating these constraints, edit their constant values to 0.
The red lines are still there because the width and height of the Content View has not yet been set.
3. Set the width and height of the Content View
Create an equal width constraint between the view and the scrollview's frame layout guide, so the scrollable content area has the same width with the scrollview (edit the 'proportional width' constraint multiplier value to "1" so that it will be equal width).
Regarding the height of the scrollable content area, we will set an explicit height constraint value to the Content View for now (for instance: 1200).
At this stage, you can scroll the scrollview in the Storyboard.
If you don't want to keep scrolling and want to see the whole scrollable content area, you can temporarily elongate the view controller height by setting it to freeform with a larger height (select the view controller -> select size inspector -> select freeform -> set the height (for instance: 1200) )
4. Design the Content View
Design the Content View through adding elements and then add constraints between each elements and the Content View (not the scroll view).
Vertical constraints must be connected from the top edge of Content View to the bottom edge of content view to ensure Auto Layout can calculate the scrollable content height after removing the explicit height.Should you put labels, set the number of lines to 0 so that it can expand based on its text content.
Finally, remove the explicit height constraint set on the content view (all constraint lines should be blue the constraints correctly has been correctly set).
Move to a specific location of the ScrollView
// x and y are the respective width and height from the top left corner of the scrollview
self.scrollView.contentOffset = CGPoint(x:250, y:100)
STACK VIEW
Introduction
Horizontal and Vertical Stackviews
Stack views creates user interfaces that can dynamically adapt to the device’s orientation, screen size, and any changes in the available space.
The views are arranged along the stack view’s axis based on their order of appearance. The exact layout varies depending on the stack view’s axis, distribution, alignment, spacing, and other properties.
1. Embed the elements in a Stackview
First, select all the elements you want to include in the stackview by clicking on them while maintaing command key pressed in the storyboard. They will appear highlighted in the outline view. You can also command-click on each button in the outline view to select them.
Once selected, click on Embed In in the Editor menu or in the Auto Layout toolbar at the bottom-right of the storyboard. A menu with available embed options will appear: choose Stack View.
2. Add constraints to the Stackview
While the stack view takes care of positioning the embedded elements, you still need to add Auto Layout constraints to position the stack view itself.
3. Set the distribution, alignment and spacing attributes
In the Attributes inspector, set the following stack view attributes: distribution, alignment, and spacing.
Distribution
Fill
Makes one subview take up the most space while the others remain at their natural size. It decides which view to stretch by examining the content hugging priority for each of the subviews. Specifically, it expands the view with the lowest horizontal content hugging priority, or if all of the priorities are equal, it expands the first view.
Fill Equally
Makes each subview the same size so they fill all the space available to the stack view. All space will be used up.
Fill Proportionally
Uses the intrinsic content size of each subview to resize them by an equal amount so that it ensures subviews remain the same size relative to each other whilte still stretching them to fit the available space.
For instance, if view A (200 px) was designed to have twice as much space as views B, C and D (100 px), that ratio will remain when they are resized (all going up by 50% to A: 300 ps, BCD: 150 px). All the subviews get proportionally bigger or smaller.
Equal spacing
Resizes the spacing between the subviews to fill the space without resizing the subviews themselves
Equal Centering
Attempts to ensure the centers of each subview are equally spaced while maintaining the spacing property’s distance between views, irrespective of how far the edge of each subview is positioned.
For instance, this might mean that the right edge of view A is only 10 px from the left edge of view 2, while the right edge of view B is 50 px from the left edge of view C, but what matters is that the centers of view 1, 2, 3 and 4 are all identically spaced.
Alignment
Nested Stackviews
When working with nested stack views, it is easiest to work from the inside out.
For instance, to obtain the embed Stackviews displayed below, you need to position the label and text field in their correct relative positions, select them both, and then click the Editor > Embed In > Stack View menu item. This create a horizontal stack view for the row. Next, you position these rows horizontally, select them, and click the Editor > Embed In > Stack View menu item again. This creates a horizontal stack of rows.
COLLECTION VIEW
1. Drag a Collection View to your View Controller and set the relevant constraints
2. Design the cell layout inside the View Controller and set the relevant constraints (except size of cell)
3. Add an outlet for the Collection View (drag the collection view to the view controller class)
4. Create a custom class for the Cell and add the relevant outlets
5.Add dataSource & delegate for the Collection View in the ViewDidLoad function
override func viewDidLoad() {
super.viewDidLoad()
collectionView.dataSource = self
collectionView.delegate = self
}
6. Add the following extensions to populate the Collection View
extension ViewController: UICollectionViewDataSource {
func numberOfSections(in collectionView: UICollectionView) -> Int {
// Return the number of sections you need for the Collection View
return 1
}
func collectionView(_ collectionView: UICollectionView, numberOfItemsInSection section: Int) -> Int {
// Return the number of cells you need for the Collection View
return 10
}
func collectionView(_ collectionView: UICollectionView, cellForItemAt indexPath: IndexPath) -> UICollectionViewCell {
let cell = collectionView.dequeueReusableCell(withReuseIdentifier: "MyCell", for: indexPath) as! MyCell
// Populate the cells with relevant content (text, image etc)
cell.textLabel.text = String(indexPath.row + 1)
return cell
}
}
extension ViewController: UICollectionViewDelegate {
func collectionView(_ collectionView: UICollectionView, didSelectItemAt indexPath: IndexPath) {
// Code to execute when a cell is selected
print(indexPath.item + 1)
}
}
7. Add the following extension to set the dimensions of the custom cell
extension ViewController: UICollectionViewDelegateFlowLayout {
func collectionView(_ collectionView: UICollectionView, layout collectionViewLayout: UICollectionViewLayout, sizeForItemAt indexPath: IndexPath) -> CGSize
{
return CGSize(width: self.collectionView.bounds.width, height: 200)
}
}
Optional: Scroll to a given cell in the Collection View
collectionView.scrollToItem(
at: IndexPath(item: 6, section: 0),
// If scroll direction is horizontal => at: left, right or centeredHorizontally
// If scroll direction is vertical => at: top or bottom
at: .top,
animated: true
)
MODAL VIEW
1. Add a View and a Visual Effect View within the top bar of the View Controller
2. Design the View and add the relevant constaints
3. Change the Blur Style parameter of the Visual Effect View to Dark
4. Create outlets for the View and Visual Effect View
Drag the View and the Visual Effect View to the View Controller code to create outlets
// Modal view outlets
@IBOutlet var BlurViewEffectOutlet: UIVisualEffectView!
@IBOutlet var PopupViewOutlet: UIView!
5. Add the following code in the ViewDidLoad section
override func viewDidLoad() {
super.viewDidLoad()
// Set the size of the blur view equal to the overall view
BlurViewEffectOutlet.bounds = self.view.bounds
// set the size of the blur view equal to the overall view
PopupViewOutlet.bounds = CGRect(x: 0, y: 0, width: self.view.bounds.width * 0.9, height: 400)
PopupViewOutlet.layer.cornerRadius = 10
}
6. Add these two functions, which allow for displaying and hiding the modal view
// Animates a view to scale in and display
func animateScaleIn(desiredView: UIView) {
let backgroundView = self.view!
backgroundView.addSubview(desiredView)
desiredView.center = backgroundView.center
desiredView.isHidden = false
desiredView.transform = CGAffineTransform(scaleX: 1.1, y: 1.1)
desiredView.alpha = 0
UIView.animate(withDuration: 0.2) {
desiredView.transform = CGAffineTransform(scaleX: 1.0, y: 1.0)
desiredView.alpha = 1
}
}
// Animates a view to scale out remove from the display
func animateScaleOut(desiredView: UIView) {
UIView.animate(withDuration: 0.2, animations: {
desiredView.transform = CGAffineTransform(scaleX: 1.1, y: 1.1)
desiredView.alpha = 0
}, completion: { (success: Bool) in
desiredView.removeFromSuperview()
})
}
7. Call the functions
// Call the function animateScaleIn when you want to display the modal viewWithTag
animateScaleIn(desiredView: BlurViewEffectOutlet)
animateScaleIn(desiredView: PopupViewOutlet)
// Call the function animateScaleOut when you want to remove the modal viewWithTag
animateScaleOut(desiredView: BlurViewEffectOutlet)
animateScaleOut(desiredView: PopupViewOutlet)
8. Outcome
STEPPER
1. Drag a stepper control and a label in the storyboard
2. Add an action function for the stepper
3. Add an outlet for the label
4. Add the following code to display the value of the stepper in the label
class ViewController: UIViewController {
// Add an outlet for the label to display the value
@IBOutlet weak var LabelOutlet: UILabel!
override func viewDidLoad() {
super.viewDidLoad()
}
@IBAction func StepperClick(_ sender: UIStepper) {
LabelOutlet.text = String(Int(sender.value))
}
}
Optional: Change the dimensions of the stepper
// Add an outlet for the stepper
@IBOutlet weak var StepperOutlet: UIStepper!
// To double the dimensions of the stepper
StepperOutlet.transform = CGAffineTransform(scaleX: 2.0, y: 2.0)
SLIDER
1. Drag a slider control and a label in the storyboard
2. Add an action function for the slider
3. Add an outlet for the label
4. Add the following code to display the value of the stepper in the label
class ViewController: UIViewController {
// Add an outlet for the label to display the value
@IBOutlet weak var LabelOutlet: UILabel!
override func viewDidLoad() {
super.viewDidLoad()
}
@IBAction func SliderClick(_ sender: UISlider) {
LabelOutlet.text = String(Int(sender.value))
}
}
SWITCH (TOGGLE)
1. Drag a switch control in the storyboard
2. Add an action function for the switch
3. Add the following code to display the value of the stepper in the label
class ViewController: UIViewController {
override func viewDidLoad() {
super.viewDidLoad()
}
@IBAction func SwitchClicked(_ sender: UISwitch) {
print(sender.isOn) // true if toggle is on or false if toggled is off
}
}
Optional: Change the dimensions of the switch
// Add an outlet for the switch
@IBOutlet weak var SwitchOutlet: UISwitch!
// To double the dimensions of the switch
SwitchOutlet.transform = CGAffineTransform(scaleX: 2.0, y: 2.0)
PLAY A VIDEO
1. Add a video file in your project
First, create a folder for the videos and add the video file into it. Then, verify that the video file appears in the Copy Bundle Resources. Otherwise, add the video file by clicking on the + button.
2. Create a Swift file named VideoView
3. Add the following code to VideoView
import UIKit
import AVKit
import AVFoundation
class VideoView: UIView {
var playerLayer: AVPlayerLayer?
var playerLooper: AVPlayerLooper!
var player: AVPlayer!
var queuePlayer = AVQueuePlayer()
func prepareVideo(videoName: String) {
let path = Bundle.main.path(forResource: videoName, ofType:"mov")
let videoUrl = URL(fileURLWithPath: path!)
player = AVPlayer(url: videoUrl)
playerLayer = AVPlayerLayer(player: player)
playerLayer?.frame = bounds
// Possible options:
// - resize (The video stretches to fill the layer’s bounds)
// - resizeAspect (The video preserves its aspect ratio and fits it within the layer’s bounds)
// - resizeAspectFill (The video preserves its aspect ratio and fills the layer’s bounds)
playerLayer?.videoGravity = AVLayerVideoGravity.resizeAspect
if let playerLayer = self.playerLayer {
layer.addSublayer(playerLayer)
}
}
func prepareVideoLoop(videoName: String) {
let pathX = Bundle.main.path(forResource: videoName, ofType:"mov")
let videoUrlX = URL(fileURLWithPath: pathX!)
playerLayer = AVPlayerLayer(player: queuePlayer)
playerLooper = AVPlayerLooper(player: queuePlayer, templateItem: AVPlayerItem(url: videoUrlX))
playerLayer?.frame = bounds
// Possible options:
// - resize (The video stretches to fill the layer’s bounds)
// - resizeAspect (The video preserves its aspect ratio and fits it within the layer’s bounds)
// - resizeAspectFill (The video preserves its aspect ratio and fills the layer’s bounds)
playerLayer?.videoGravity = AVLayerVideoGravity.resizeAspect
if let playerLayer = self.playerLayer {
layer.addSublayer(playerLayer)
}
}
func playVideo() {
player.play()
}
func playVideoLoop() {
queuePlayer.play()
}
func pauseVideoLoop() {
queuePlayer.pause()
}
func replaceVideoLoop(videoName: String){
let pathY = Bundle.main.path(forResource: videoName, ofType:"mov")
let videoUrlY = URL(fileURLWithPath: pathY!)
playerLooper = AVPlayerLooper(player: queuePlayer, templateItem: AVPlayerItem(url: videoUrlY))
}
}
4. Add a view (with constraints) to the storyboard and set its class to VideoView
5. Add an outlet for the view
6. Add the following code in the main View Controller
class ViewController: UIViewController {
@IBOutlet weak var VideoA: VideoView!
override func viewDidLoad() {
super.viewDidLoad()
// To play a video once
VideoA.prepareVideo(videoName: "SampleVideo")
VideoA.playVideo()
// To play a video on loop
VideoA.prepareVideoLoop(videoName: "SampleVideo")
VideoA.playVideoLoop()
}
}
RECORD AUDIO
XXXX
RECORD AUDIO
1. Import the AVFoundation framework
import AVFoundation
2. Add missing conformance to AVAudioRecorderDelegate and AVAudioPlayerDelegate
class ViewController: UIViewController, AVAudioRecorderDelegate, AVAudioPlayerDelegate {
// ...
}
3. Add the following key to the Info Plist file
In order to ask the user for his permission to record audio, add NSMicrophoneUsageDescription key with a string value explaining to the user that the app requires audio recording (for instance: Please accept audio recording setting)
4. Declare the following variables in the ViewController class
var recordingSession: AVAudioSession!
var audioRecorder: AVAudioRecorder!
var audioPlayer: AVAudioPlayer!
5. Declare the following functions
func setupRecorder(){
do {
try AVAudioSession.sharedInstance().setCategory(.record, mode: .default)
} catch {
print("problem session")
}
let paths = FileManager.default.urls(for: .documentDirectory, in: .userDomainMask)
let documentsDirectory = paths[0]
let audioFilename = documentsDirectory.appendingPathComponent("audioFile.m4a")
let settings = [
AVFormatIDKey: Int(kAudioFormatAppleLossless),
AVEncoderAudioQualityKey: AVAudioQuality.high.rawValue,
AVEncoderBitRateKey: 32000,
AVNumberOfChannelsKey: 2,
AVSampleRateKey: 44100.0] as [String: Any]
var error: NSError?
do {
audioRecorder = try AVAudioRecorder(url: audioFilename, settings: settings)
} catch {
audioRecorder = nil
print("Audiorecorder nil")
}
if let err = error {
print("AVAudioRecorder error: \(err.localizedDescription)")
} else {
audioRecorder.delegate = self
audioRecorder.prepareToRecord()
}
}
func preparePlayer(){
do {
try AVAudioSession.sharedInstance().setCategory(.playback, mode: .default)
} catch {
print("problem session player")
}
do {
audioPlayer = try AVAudioPlayer(contentsOf: getFileURL())
audioPlayer.delegate = self
audioPlayer.volume = 1.0
} catch {
if let err = error as Error?{
print("AVAudio player error: \(err.localizedDescription)")
}
}
}
func getFileURL() -> URL{
let fileManager = FileManager.default
let urls = fileManager.urls(for: .documentDirectory, in: .userDomainMask)
let documentDirectory = urls[0] as URL
let soundURL = documentDirectory.appendingPathComponent("audioFile.m4a")
return soundURL
}
func RecordAudio(){
setupRecorder()
audioRecorder.record()
}
func StopRecording(){
audioRecorder.stop()
audioRecorder = nil
}
func PlayAudioRecording(){
preparePlayer()
audioPlayer.play()
}
6. Call the functions
// Start audio recording
RecordAudio()
// Stop audio recording
StopRecording()
// Play recorder audio
PlayAudioRecording()
PLAY AN AUDIO FILE
1. Add an audio file to your project
XXXXX
2. Declare the following function
func PlayAudio(name : String, type: String){
guard let url = Bundle.main.url(forResource: name, withExtension: type) else { return }
do {
// Choose code option below depending on preferences
// Option A: to play audio on headphone if connected or otherwise on loud speaker
try AVAudioSession.sharedInstance().setCategory(AVAudioSession.Category.playback)
// Option B: to play audio on headphones if connected or otherwise on ear speaker
try AVAudioSession.sharedInstance().setCategory(AVAudioSession.Category.playAndRecord, options: .allowBluetooth)
// Option C: to play audio on loud speaker in all cases
try AVAudioSession.sharedInstance().setCategory(AVAudioSession.Category.playAndRecord)
try AVAudioSession.sharedInstance().overrideOutputAudioPort(.speaker)
// Option D: to play audio on ear speaker in all cases
try AVAudioSession.sharedInstance().setCategory(AVAudioSession.Category.playAndRecord)
try AVAudioSession.sharedInstance().overrideOutputAudioPort(.none)
try AVAudioSession.sharedInstance().setActive(true)
player = try AVAudioPlayer(contentsOf: url)
guard let player = player else { return }
player.play()
} catch let error {
print(error.localizedDescription)
}
}
3. Call the function to play an audio file
PlayAudio(name: "sampleaudio", type: "mp3")
TEXT TO SPEACH
1. Import AVFoundation and CoreMIDI frameworks
import UIKit
import AVFoundation
2. Declare the following function
func textToSpeakReading(textToRead : String){
let session: AVAudioSession = AVAudioSession.sharedInstance()
let synthesizer = AVSpeechSynthesizer()
do {
// Choose code option below depending on preferences
// Option A: to play audio on headphone if connected or otherwise on loud speaker
try session.setCategory(AVAudioSession.Category.playback)
// Option B: to play audio on headphones if connected or otherwise on ear speaker
try session.setCategory(AVAudioSession.Category.playAndRecord, options: .allowBluetooth)
// Option C: to play audio on loud speaker in all cases
try session.setCategory(AVAudioSession.Category.playAndRecord)
try session.overrideOutputAudioPort(.speaker)
// Option D: to play audio on ear speaker in all cases
try session.setCategory(AVAudioSession.Category.playAndRecord)
try session.overrideOutputAudioPort(.none)
try session.setActive(true)
} catch {
print("Couldn't override output audio port")
}
let utterance = AVSpeechUtterance(string: textToRead)
utterance.voice = AVSpeechSynthesisVoice(language: "en-US")
utterance.voice = AVSpeechSynthesisVoice(identifier: "com.apple.ttsbundle.siri_female_en-US_compact")
utterance.volume = 1.0
synthesizer.speak(utterance)
}
3. Call the function to read text
textToSpeakReading(textToRead: "Hi! Today is a nice day with a beautiful weather")
SEND WHATSAPP MESSAGE
Send a prefilled whatsapp message from the app
let urlWhats = "https://wa.me/?text=Lorem ipsum dolor sit amet, consectetur adipiscing elit. Nam hendrerit nisi sed sollicitudin pellentesque. Nunc posuere purus rhoncus pulvinar aliquam. Ut aliquet tristique nisl vitae volutpat. \n\n Nulla aliquet porttitor venenatis. Donec a dui et dui fringilla consectetur id nec massa. Aliquam erat volutpat. Sed ut dui ut lacus dictum fermentum vel tincidunt neque."
if let urlString = urlWhats.addingPercentEncoding(withAllowedCharacters: NSCharacterSet.urlQueryAllowed) {
if let whatsappURL = NSURL(string: urlString) {
if UIApplication.shared.canOpenURL(whatsappURL as URL) {
UIApplication.shared.open(whatsappURL as URL, options: [:], completionHandler: nil)
} else {
print("Cannot Open Whatsapp")
}
}
}
Send a prefilled whatsapp message to a given number
let urlWhats = "https://wa.me/15551234567/?text=Lorem ipsum dolor sit amet, consectetur adipiscing elit. Nam hendrerit nisi sed sollicitudin pellentesque. Nunc posuere purus rhoncus pulvinar aliquam. Ut aliquet tristique nisl vitae volutpat. \n\n Nulla aliquet porttitor venenatis. Donec a dui et dui fringilla consectetur id nec massa. Aliquam erat volutpat. Sed ut dui ut lacus dictum fermentum vel tincidunt neque."
// The number must be a full phone number in international format. Omit any brackets, dashes, plus signs, and leading zeros when adding the phone number in international format.
if let urlString = urlWhats.addingPercentEncoding(withAllowedCharacters: NSCharacterSet.urlQueryAllowed) {
if let whatsappURL = NSURL(string: urlString) {
if UIApplication.shared.canOpenURL(whatsappURL as URL) {
UIApplication.shared.open(whatsappURL as URL, options: [:], completionHandler: nil)
} else {
print("Cannot Open Whatsapp")
}
}
}
SEND SMS
Send an sms from your application
let textMessageRecipients = ["1-800-867-5309"] // optional for pre-populating the recipients list (optional, depending on your needs)
class MessageComposer: NSObject, MFMessageComposeViewControllerDelegate {
// A wrapper function to indicate whether or not a text message can be sent from the user's device
func canSendText() -> Bool {
return MFMessageComposeViewController.canSendText()
}
// Configures and returns a MFMessageComposeViewController instance
func configuredMessageComposeViewController(messageX: String) -> MFMessageComposeViewController {
let messageComposeVC = MFMessageComposeViewController()
messageComposeVC.messageComposeDelegate = self // Make sure to set this property to self, so that the controller can be dismissed!
//messageComposeVC.recipients = textMessageRecipients
messageComposeVC.body = messageX
return messageComposeVC
}
// MFMessageComposeViewControllerDelegate callback - dismisses the view controller when the user is finished with it
func messageComposeViewController(_ controller: MFMessageComposeViewController, didFinishWith result: MessageComposeResult) {
controller.dismiss(animated: true, completion: nil)
}
}
let messageComposer = MessageComposer()
if (messageComposer.canSendText()) {
// Obtain a configured MFMessageComposeViewController
let messageComposeVC = messageComposer.configuredMessageComposeViewController(messageX: "Lorem ipsum dolor sit amet, consectetur adipiscing elit. Nam hendrerit nisi sed sollicitudin pellentesque. Nunc posuere purus rhoncus pulvinar aliquam. Ut aliquet tristique nisl vitae volutpat. \n\n Nulla aliquet porttitor venenatis. Donec a dui et dui fringilla consectetur id nec massa. Aliquam erat volutpat. Sed ut dui ut lacus dictum fermentum vel tincidunt neque.")
present(messageComposeVC, animated: true, completion: nil)
} else {
let alert = UIAlertController(title: "Cannot Send Text Message", message: "Your device is not able to send text messages.", preferredStyle: UIAlertController.Style.alert)
alert.addAction(UIAlertAction(title: NSLocalizedString("OK", comment: "Default action"), style: .default, handler: { _ in
NSLog("The \"OK\" alert occured.")
}))
self.present(alert, animated: true, completion: nil)
}
SEND EMAIL | IPhone Mail App
1. Declare the following function
func sendEmail() {
if MFMailComposeViewController.canSendMail() {
let mail = MFMailComposeViewController()
mail.mailComposeDelegate = self
mail.setSubject("Invitation to myApp")
mail.setMessageBody("Hi,
Please downoad the app myApp in the Apple Store.
MyApp team
", isHTML: true)
present(mail, animated: true)
} else {
// show failure alert
}
}
func mailComposeController(_ controller: MFMailComposeViewController, didFinishWith result: MFMailComposeResult, error: Error?) {
controller.dismiss(animated: true)
}
2. Call the function to send an email
sendEmail()
SEND EMAIL | External Server
1. Import SwiftSMTP framework
// EMAIL SMTP Setup (1)
import SwiftSMTP
2. Declare the following variable as server settings
// EMAIL SMTP SETUP (2)
let smtp = SMTP(
hostname: "mail.infomaniak.com", // SMTP server address
email: "no-reply@mywebsite.com", // username to login
password: "Password.12345" // password to login
)
3. Declare the following function
// EMAIL SMTP SETUP (3)
func sendEmails(EmailAddress:String){
let senderEmail = Mail.User(name: "Betteo", email: "no-reply@betteo.net")
let receiverEmail = Mail.User(name: "Unknown", email: EmailAddress)
let htmlAttachment = Attachment(
htmlContent: "Hi,
Please downoad the app myApp in the Apple Store.
MyApp team
"
)
let mail = Mail(
from: senderEmail,
to: [receiverEmail],
subject: "Invitation to MyApp",
text: "",
attachments: [htmlAttachment]
)
smtp.send(mail) { (error) in
if let error = error {
print(error)
} else {
DispatchQueue.main.asyncAfter(deadline: .now() ) {
self.SendEmail_Alert_Outlet.isHidden = false
}
DispatchQueue.main.asyncAfter(deadline: .now() + 3) {
self.SendEmail_Alert_Outlet.isHidden = true
}
}
}
}
3. Call the function to send an email
sendEmails(EmailAddress: "Peter12345@gmail.com")
LOADING SCREEN
1. Create a new View Controller named loadingVC with the following code
class VC_Loading: UIViewController {
var loadingActivityIndicator: UIActivityIndicatorView = {
let indicator = UIActivityIndicatorView()
indicator.style = .large
indicator.color = .white
indicator.startAnimating()
indicator.autoresizingMask = [
.flexibleLeftMargin, .flexibleRightMargin,
.flexibleTopMargin, .flexibleBottomMargin
]
return indicator
}()
var blurEffectView: UIVisualEffectView = {
let blurEffect = UIBlurEffect(style: .dark)
let blurEffectView = UIVisualEffectView(effect: blurEffect)
blurEffectView.alpha = 0.8
blurEffectView.autoresizingMask = [
.flexibleWidth, .flexibleHeight
]
return blurEffectView
}()
override func viewDidLoad() {
super.viewDidLoad()
view.backgroundColor = UIColor.black.withAlphaComponent(0.5)
blurEffectView.frame = self.view.bounds
view.insertSubview(blurEffectView, at: 0)
loadingActivityIndicator.center = CGPoint(
x: view.bounds.midX,
y: view.bounds.midY
)
view.addSubview(loadingActivityIndicator)
}
}
2. Insert the following code in the initial view controller (functions to display and hide the loading screen)
func DisplayLoading(){
let loadingVC = VC_Loading()
// Animate loadingVC over the existing views on screen
loadingVC.modalPresentationStyle = .overCurrentContext
// Animate loadingVC with a fade in animation
loadingVC.modalTransitionStyle = .crossDissolve
// Display the loading screen
present(loadingVC, animated: true, completion: nil)
}
func EndLoading(){
// Remove the loading screen
self.dismiss(animated: false, completion:nil)
}
3. Call the functions to display the loading screen
First, call the function DisplayLoading() when the loading process starts.
Then, call the function EndLoading() when the loading process is finished.
4. The following loading screen will be displayed
Plugin alternative
As an alternative to the above code, you can use the JGProgressHUD plugin:
JGProgressHUD Github
USER ONBOARDING FLOW
Introduction
We will need three types of View Controllers
• One View Controller named Content_VC
• One Page View Controller named Page_VC
• X View Controllers corresponding to the Onboarding screens (OnboardingA_VC, OnboardingB_VC to OnboardingX_VC)
1. Create Content_VC (View Controller)
1) Add a ViewController in the storyboard
2) Add a Container View in the ViewController
3) Add the relevant elements in the ViewController (Next, Skip, PageView control)
4) Create a new file in relation to Content_VC
5) Link ContentVC to the new file in the storyboard
2. Create Page_VC (Page View Controller)
1) Add a PageViewController in the storyboard
2) Create a new file in relation to Page_VC
3) Link PageVC to the new file in the storyboard and add a storyboard ID
4) Link the ContainerView to the PageViewController in the storyboard
3. Create the onboarding screens named OnboardingX_VC (View Controllers)
1) Add the number of ViewControllers you need in the storyboard
2) Create new files in relation to each new ViewController OnboardingX_VC
3) Link each new file to its corresponding ViewController in the storyboard (class) and add a Storyboard ID
4. Add the following code in Content_VC (ViewController with the ContainerView)
class Content_VC: UIViewController {
@IBOutlet weak var PageControlOutlet: UIPageControl!
var PageVC_Instance: Page_VC? {
didSet {
PageVC_Instance?.Var_PageVC_Delegate = self
}
}
override func viewDidLoad() {
super.viewDidLoad()
}
override func prepare(for segue: UIStoryboardSegue, sender: Any?) {
if let PageVC_Instance = segue.destination as? Page_VC {
self.PageVC_Instance = PageVC_Instance
}
}
}
extension Content_VC: PageVC_InstanceDelegate{
// Called when the number of pages is updated
func PageVC_Instance(PageVC_Instance: Page_VC, didUpdatePageCount count: Int) {
PageControlOutlet.numberOfPages = count
}
// Called when the current index is updated
func PageVC_Instance(PageVC_Instance: Page_VC, didUpdatePageIndex index: Int) {
PageControlOutlet.currentPage = index
}
}
5. Add the following code in Page_VC (Page View Controller)
protocol PageVC_Delegate: AnyObject {
func PageVC_Instance(PageVC_Instance: Page_VC, didUpdatePageCount count: Int)
// count: total number of page
func PageVC_Instance(PageVC_Instance: Page_VC, didUpdatePageIndex index: Int)
// index of the currently visible page
}
class Page_VC: UIPageViewController {
let pageControl = UIPageControl()
weak var Var_PageVC_Delegate: PageVC_Delegate?
lazy var vcList:[UIViewController] = {
let storyboard = UIStoryboard(name: "Main", bundle: nil)
let firstVC = storyboard.instantiateViewController(identifier: "PageVC_SlideA") // storyboard ID
let secondVC = storyboard.instantiateViewController(identifier: "PageVC_SlideB")
let thirdVC = storyboard.instantiateViewController(identifier: "PageVC_SlideC")
return [firstVC, secondVC, thirdVC]
}()
override func viewDidLoad() {
super.viewDidLoad()
dataSource = self
delegate = self
if let vc = vcList.first{
self.setViewControllers([vc], direction: .forward, animated: true, completion: nil)
}
Var_PageVC_Delegate?.PageVC_Instance(PageVC_Instance: self, didUpdatePageCount: vcList.count)
}
private func notifyDelegateOfNewIndex() {
if let firstViewController = viewControllers?.first, let index = vcList.firstIndex(of: firstViewController) {
Var_PageVC_Delegate?.PageVC_Instance(PageVC_Instance: self, didUpdatePageIndex: index)
}
}
// Optional: programmatically go to the next onboarding screen
func scrollToNextViewController() {
if let visibleViewController = viewControllers?.first,
let nextViewController = pageViewController(self, viewControllerAfter: visibleViewController) {
scrollToViewController(viewController: nextViewController)
}
}
private func scrollToViewController(viewController: UIViewController,
direction: UIPageViewController.NavigationDirection = .forward) {
setViewControllers([viewController],
direction: direction,
animated: true,
completion: { (finished) -> Void in
self.notifyDelegateOfNewIndex()
})
}
} // End Class Page_VC
extension Page_VC : UIPageViewControllerDataSource{
func pageViewController(_ pageViewController: UIPageViewController, viewControllerBefore viewController: UIViewController) -> UIViewController? {
guard let index = vcList.lastIndex(of: viewController) else { return nil }
let previousIndex = index - 1
guard previousIndex >= 0 else {return nil}
guard previousIndex < vcList.count else {return nil}
return vcList[previousIndex]
}
func pageViewController(_ pageViewController: UIPageViewController, viewControllerAfter viewController: UIViewController) -> UIViewController? {
guard let index = vcList.lastIndex(of: viewController) else { return nil }
let previousIndex = index + 1
guard previousIndex >= 0 else {return nil}
guard previousIndex < vcList.count else {return nil}
return vcList[previousIndex]
}
}
extension Page_VC : UIPageViewControllerDelegate {
// Code to run after change page
func pageViewController(_ pageViewController: UIPageViewController, didFinishAnimating finished: Bool, previousViewControllers: [UIViewController], transitionCompleted completed: Bool){
notifyDelegateOfNewIndex()
}
}
Plugin alternative
As an alternative to the above code, you can use the Ramotion PaperOnboarding plugin:
Ramotion PaperOnboarding Github
KEYBOARD | Dismiss keyboard
A. Dismiss keyboard on pressing return
class ViewController: UIViewController {
@IBOutlet weak var textField: UITextField!
override func viewDidLoad() {
super.viewDidLoad()
textField.delegate = self // set delegate
}
}
extension ViewController: UITextFieldDelegate {
func textFieldShouldReturn(_ textField: UITextField) -> Bool {
textField.resignFirstResponder() // dismiss keyboard
return true
}
}
B. Dismiss keyboard on pressing return on last input field
extension VC_Main : UITextFieldDelegate{
func textFieldShouldReturn(_ textField: UITextField) -> Bool {
// Check if there is any other text-field in the view whose tag is +1 greater than the current text-field on which the return key was pressed.
if let nextField = self.view.viewWithTag(textField.tag + 1) as? UITextField {
// If yes → move the cursor to that next text-field.
nextField.becomeFirstResponder()
} else {
// If No → dismiss the keyboard
textField.resignFirstResponder()
}
return false
}
}
C. Dismiss keyboard on tapping outside the textfield
class ViewController: UIViewController {
@IBOutlet weak var textField: UITextField!
override func viewDidLoad() {
super.viewDidLoad()
let tap = UITapGestureRecognizer(target: self, action: #selector(handleTap))
view.addGestureRecognizer(tap) // Add gesture recognizer to background view
}
@objc func handleTap() {
textField.resignFirstResponder() // dismiss keyoard
}
}
D. Programmatically dissmiss the keyboard
func hideKeyboard() {
self.view.endEditing(true)
}
POPUP ALERT WINDOW
Function to display an alert popup window
func DisplayAlert(){
let dialogMessage = UIAlertController(title: "Reminder", message: "Drink water", preferredStyle: .alert)
let done = UIAlertAction(title: "Done", style: .default, handler: { (action) -> Void in
// Code to execute when user clicked on Done
})
let ok = UIAlertAction(title: "OK", style: .default, handler: { (action) -> Void in
// Code to execute when user clicked on OK
})
dialogMessage.addAction(done)
dialogMessage.addAction(ok)
self.present(dialogMessage, animated: true, completion: nil)
}
// Available UIAlertAction styles: .default (normal text), .cancel (bold text), .destructive (red text)
// Available UIAlertControllerStyle styles: .alert (displayed modally), .actionSheet (displayed in the context of the view controller that presented it)
Alert popup window
Function to display an alert which is located in an external swift file
// Code to put in the external Swift file (within struct Constants in Constants.swift file)
static func DisplayAlert()->UIAlertController{
let dialogMessage = UIAlertController(title: "Reminder", message: "Drink water", preferredStyle: .alert)
let ok = UIAlertAction(title: "OK", style: .default, handler: { (action) -> Void in
// Code to execute when user clicked on OK
})
dialogMessage.addAction(ok)
return dialogMessage
}
// Code to put in the View Controller where the alert will be displayed
present(Constants.DisplayAlertInternet(), animated: true, completion: nil)
Display an alert with an input text field
// Code to put in the external Swift file (within struct Constants in Constants.swift file)
func DisplayAlert(){
let dialogMessage = UIAlertController(title: "Reminder", message: "Drink water", preferredStyle: .alert)
// Add text field
dialogMessage.addTextField(configurationHandler: { textField in
textField.placeholder = "Type in your name"
})
let ok = UIAlertAction(title: "OK", style: .default, handler: { (action) -> Void in
// Code to execute when user clicked on OK
print("PIN code typed = \(dialogMessage.textFields?.first?.text ?? "")")
})
dialogMessage.addAction(ok)
self.present(dialogMessage, animated: true, completion: nil)
}
ADD A TAP GESTURE TO A LABEL
1. Connect the label to your ViewController as and IBOutlet
@IBOutlet weak var label: UILabel!
2. Add the following code in the viewDidLoad function
let labelTap = UITapGestureRecognizer(target: self, action: #selector(self.labelTapped(_:)))
self.label.isUserInteractionEnabled = true
self.label.addGestureRecognizer(labelTap)
3. Add this function in the ViewController class
@objc func labelTapped(_ sender: UITapGestureRecognizer) {
// Code to execute when the label is tapped
print("labelTapped")
}
CHECK INTERNET CONNECTION
Declare the following variable and function
import Network
static var InternetConnectionOn = false
static func checkConnection() {
let monitor = NWPathMonitor()
monitor.pathUpdateHandler = { path in
if path.status == .satisfied {
InternetConnectionOn = true
//print("Device connected to internet")
} else {
InternetConnectionOn = false
//print("Device not connected to internet")
}
}
let queue = DispatchQueue(label: "Network")
monitor.start(queue: queue)
}
Call the function to verify if device connected to internet
checkConnection()
if InternetConnectionOn{
// Code to execute if device connected to internet
print("Device connected to internet")
} else {
// Code to execute if device connected to internet
print("Device not connected to internet")
}