Variable is not updating - func takes default variable - swift

In my ThirdScreenViewController I change the variable number with the IBAction pressed.
import Foundation
import UIKit
class ThirdScreenViewController: UIViewController {
override func viewDidLoad() {
super.viewDidLoad()
}
var weatherManager = WeatherManager()
var team = "leer"
static var number = 1
#IBAction func bayernMunchen(_ sender: UIButton) {
team = "bayernMunchen"
}
#IBAction func borussiaDortmund(_ sender: UIButton) {
team = "borussiaDortmund"
}
#IBAction func schalke(_ sender: UIButton) {
team = "schalke"
}
#IBAction func pressed(_ sender: UIButton) {
switch team {
case "bayernMunchen":
ThirdScreenViewController.number = 46
case "borussiaDortmund":
ThirdScreenViewController.number = 41
case "schalke":
ThirdScreenViewController.number = 45
default: print(8)
}
let storyBoard : UIStoryboard = UIStoryboard(name: "Main", bundle:nil)
let nextViewController = storyBoard.instantiateViewController(withIdentifier: "WeatherViewController") as! WeatherViewController
self.present(nextViewController, animated:true, completion:nil)
}
}
In an other swift (not a View Controller) file I have a function which takes number and does something with it.
import Foundation
import UIKit
var TeamOne = ""
var TeamTwo = ""
var ScoreOne = ""
var ScoreTwo = ""
var TeamThree = ""
var TeamFour = ""
var ScoreThree = ""
var ScoreFour = ""
var cityName = ThirdScreenViewController.number
struct WeatherManager {
let weatherURL = "https://livescore-api.com/api-client/teams/matches.json?number=10&team_id=19&key=d33FTnnd6qwvEmjz&secret=BbO3REPYFXvb7fpkit0cQnpXNWssiL1U&number=3&team_id=\(cityName)"
func fetchWeather () {
let urlString = "\(weatherURL)"
perfromRequest(urlString: urlString)
}
func perfromRequest(urlString: String)
{
//1.Url erstellen
if let url = URL(string: urlString) {
//2. URLSession starten
let session = URLSession(configuration: .default)
//3. Give session a task
let task = session.dataTask(with: url) { (gettingInfo, response, error) in
if error != nil{
print(error!)
return
}
if let safeFile = gettingInfo {
self.parseJSON(weatherFile: safeFile)
}
}
//4. Start the task
task.resume()
}
}
//Das Ergebnis von oben wird hier ausgegeben
func parseJSON(weatherFile: Data) {
let decoder = JSONDecoder()
do{
let decodedFile = try decoder.decode(WeatherFile.self, from: weatherFile)
TeamOne = decodedFile.data[0].home_name
ScoreOne = decodedFile.data[0].score
TeamTwo = decodedFile.data[0].away_name
ScoreTwo = decodedFile.data[0].score
TeamThree = decodedFile.data[1].home_name
ScoreThree = decodedFile.data[1].score
TeamFour = decodedFile.data[1].away_name
ScoreFour = decodedFile.data[1].score
} catch {
print(error)
}
}
}
In a third swift file I use this func weatherManager.fetchWeather() to call what happens in my second swift file.
But here is the problem. It takes the variable number with the default value 1 and not with the value 41/46/45. What am I doing wrong?

Basically global variables outside of any class and static variables to share data is bad practice.
Apart from that to get the team ID dynamically delete the line
var cityName = ThirdScreenViewController.number
In the struct replace
let weatherURL = "https://livescore-api.com/api-client/teams/matches.json?number=10&team_id=19&key=d33FTnnd6qwvEmjz&secret=BbO3REPYFXvb7fpkit0cQnpXNWssiL1U&number=3&team_id=\(cityName)"
with
let weatherURL = "https://livescore-api.com/api-client/teams/matches.json?number=10&team_id=19&key=d33FTnnd6qwvEmjz&secret=BbO3REPYFXvb7fpkit0cQnpXNWssiL1U&number=3&team_id="
and
let urlString = "\(weatherURL)"
with
let urlString = weatherURL + String(ThirdScreenViewController.number)
Note: Consider to rename the weather related stuff to the team related stuff

Related

Use of unresolved identifier 'self' (CoreData)

I am using this line below :
self.present(activityViewController, animated: true, completion: nil)
And I am getting an error of - Use of unresolved identifier 'self'. Any ideas about how to resolve this? To me it looks as it it is subordinate to the class, but clearly doing something wrong. Any help would be appreciated.
import UIKit
import CoreData
class CoreDataViewController: UIViewController {
#IBOutlet weak var CoreDataView: UITableView!
let context = (UIApplication.shared.delegate as! AppDelegate).persistentContainer.viewContext
var items:[Checkins]?
var btnnames = [""]
override func viewDidLoad() {
super.viewDidLoad()
// CoreDataView.dataSource = self
// CoreDataView.delegate = self
storeTranscription()
// Loads the current data
getTranscriptions()
// fetchCheckins()
let btn1name = btnnames[0]
let btn2name = btnnames[1]
let btn3name = btnnames[2]
let btn4name = btnnames[3]
let btn5name = btnnames[4]
let btn6name = btnnames[5]
// print(btnnames)
print(btn1name, btn2name, btn3name, btn4name, btn5name, btn6name)
}
#IBAction func export(_ sender: Any) {
exportDatabase()
}
#IBOutlet weak var Table_label: UILabel!
}
var CheckinDate: Date? = Date()
var fetchedStatsArray: [NSManagedObject] = []
let context = (UIApplication.shared.delegate as! AppDelegate).persistentContainer.viewContext
func storeTranscription() {
//retrieve the entity that we just created
let entity = NSEntityDescription.entity(forEntityName: "Checkins", in: context)
let transc = NSManagedObject(entity: entity!, insertInto: context) as! Checkins
//set the entity values
transc.who = "Who"
transc.reason = "Reason for visit"
transc.date = CheckinDate
//save the object
do {
try context.save()
print("saved!")
} catch let error as NSError {
print("Could not save \(error), \(error.userInfo)")
} catch {
}
}
func getTranscriptions () {
//create a fetch request, telling it about the entity
let fetchRequest: NSFetchRequest<Checkins> = Checkins.fetchRequest()
do {
//go get the results
let searchResults = try context.fetch(fetchRequest)
fetchedStatsArray = searchResults as [NSManagedObject]
//I like to check the size of the returned results!
print ("num of results = \(searchResults.count)")
//You need to convert to NSManagedObject to use 'for' loops
for trans in searchResults as [NSManagedObject] {
//get the Key Value pairs (although there may be a better way to do that...
print("\(trans.value(forKey: "who")!)")
let mdate = trans.value(forKey: "CheckinDate") as! Date
print(mdate)
}
} catch {
print("Error with request: \(error)")
}
}
func exportDatabase() {
let exportString = createExportString()
saveAndExport(exportString: exportString)
}
func saveAndExport(exportString: String) {
let exportFilePath = NSTemporaryDirectory() + "Checkins.csv"
let exportFileURL = NSURL(fileURLWithPath: exportFilePath)
FileManager.default.createFile(atPath: exportFilePath, contents: NSData() as Data, attributes: nil)
//var fileHandleError: NSError? = nil
var fileHandle: FileHandle? = nil
do {
fileHandle = try FileHandle(forWritingTo: exportFileURL as URL)
} catch {
print("Error with fileHandle")
}
if fileHandle != nil {
fileHandle!.seekToEndOfFile()
let csvData = exportString.data(using: String.Encoding.utf8, allowLossyConversion: false)
fileHandle!.write(csvData!)
fileHandle!.closeFile()
let firstActivityItem = NSURL(fileURLWithPath: exportFilePath)
let activityViewController : UIActivityViewController = UIActivityViewController(
activityItems: [firstActivityItem], applicationActivities: nil)
activityViewController.excludedActivityTypes = [
UIActivity.ActivityType.assignToContact,
UIActivity.ActivityType.saveToCameraRoll,
UIActivity.ActivityType.postToFlickr,
UIActivity.ActivityType.postToVimeo,
UIActivity.ActivityType.postToTencentWeibo
]
self.present(activityViewController, animated: true, completion: nil)
}
}
func createExportString() -> String {
var checkinwho: String?
var checkinreason: String?
var export: String = NSLocalizedString("who, reason, date \n", comment: "")
for (index, itemList) in fetchedStatsArray.enumerated() {
if index <= fetchedStatsArray.count - 1 {
checkinwho = Checkins.value(forKey: "who") as! String?
checkinreason = itemList.value(forKey: "reason") as! String?
let Datevar = Checkins.value(forKey: "date") as! Date
let whostring = checkinwho
let reasonstring = checkinreason
let DateSting = "\(Datevar)"
export += "\(whostring!),\(reasonstring!),\(DateSting) \n"
}
}
print("This is what the app will export: \(export)")
return export
}
Remove the } on this line
#IBOutlet weak var Table_label: UILabel!
}
and put another } at the end of this file.

Extracting data from csv file to put on UI table view

I was wondering if I could ask a question regarding csv/http posting. I want my data to update within my app after I pull the data from my github csv file, but when I do, it doesn't update within the app but just prints the numbers. What's wrong with my code? Thanks!
class NewStats: UITableViewController {
var didTapMenuType: ((NewMenu) -> Void)?
var Num2:String = "2"
#IBOutlet weak var MultnomahText: UILabel!
#IBOutlet weak var MultnomahView: UIProgressView!
override func viewDidLoad() {
let url = URL(string: "SampleUrl.csv")!
let task = URLSession.shared.dataTask(with: url) {(data, response, error) in
guard let data = data else { return }
let str = (String(data: data, encoding: .utf8)!)
let fullNameArr = str.components(separatedBy: ",")
let Num1 = fullNameArr[0]
self.Num2 = fullNameArr[1]
let Num3 = fullNameArr[2]
let Num4 = fullNameArr[3]
let Num5 = fullNameArr[4]
let Num6 = fullNameArr[5]
let Num7 = fullNameArr[6]
let Num8 = fullNameArr[7]
let Num9 = fullNameArr[8]
let Num10 = fullNameArr[9]
print(Num1);
print(self.Num2);
print(Num3);
print(Num4);
print(Num5);
print(Num6);
print(Num7);
print(Num8);
print(Num9);
print(Num10);
}
task.resume()
super.viewDidLoad()
DispatchQueue.main.async {
self.tableView.reloadData()
}
print(self.Num2);
self.MultnomahText.text = "Multnomah:" + self.Num2
self.MultnomahView.setProgress(0.5, animated: true)
}
After the print(Num10)
DispatchQueue.main.async {
self.MultnomahText.text = "Multnomah:" + self.Num2
self.MultnomahView.setProgress(0.5, animated: true)
self.tableView.reloadData()
}
Hopefully this helps!

Why does my segue not wait until completion handler finished?

I have a page based app, using RootViewController, ModelViewController, DataViewController, and a SearchViewController.
In my searchViewController, I search for an item and then add or remove that Item to an array which is contained in a Manager class(and UserDefaults), which the modelViewController uses to instantiate an instance of DataViewController with the correct information loaded using the dataObject. Depending on whether an Item was added or removed, I use a Bool to determine which segue was used, addCoin or removeCoin, so that the RootViewController(PageView) will show either the last page in the array, (when a page is added) or the first (when removed).
Everything was working fine until I ran into an error which I can not diagnose, the problem is that when I add a page, the app crashes, giving me a "unexpectadely found nil when unwrapping an optional value"
This appears to be the problem function, in the searchViewController 'self.performSegue(withIdentifier: "addCoin"' seems to be called instantly, even without the dispatchque:
#objc func addButtonAction(sender: UIButton!) {
print("Button tapped")
if Manager.shared.coins.contains(dataObject) {
Duplicate()
} else if Manager.shared.coins.count == 5 {
max()
} else {
Manager.shared.addCoin(coin: dataObject)
CGPrices.shared.getData(arr: true, completion: { (success) in
print(Manager.shared.coins)
DispatchQueue.main.async {
self.performSegue(withIdentifier: "addCoin", sender: self)
}
})
}
searchBar.text = ""
}
Meaning that In my DataViewController, this function will find nil:
func getIndex() {
let index = CGPrices.shared.coinData.index(where: { $0.id == dataObject })!
dataIndex = index
}
I can't find out why it does not wait for completion.
I also get this error about threads:
[Assert] Cannot be called with asCopy = NO on non-main thread.
which is why I try to do the push segue using dispatch que
Here is my searchViewController full code:
import UIKit
class SearchViewController: UIViewController, UISearchBarDelegate {
let selectionLabel = UILabel()
let searchBar = UISearchBar()
let addButton = UIButton()
let removeButton = UIButton()
var filteredObject: [String] = []
var dataObject = ""
var isSearching = false
//Add Button Action.
#objc func addButtonAction(sender: UIButton!) {
print("Button tapped")
if Manager.shared.coins.contains(dataObject) {
Duplicate()
} else if Manager.shared.coins.count == 5 {
max()
} else {
Manager.shared.addCoin(coin: dataObject)
CGPrices.shared.getData(arr: true, completion: { (success) in
print(Manager.shared.coins)
DispatchQueue.main.async {
self.performSegue(withIdentifier: "addCoin", sender: self)
}
})
}
searchBar.text = ""
}
//Remove button action.
#objc func removeButtonActon(sender: UIButton!) {
print("Button tapped")
if Manager.shared.coins.contains(dataObject) {
Duplicate()
} else if Manager.shared.coins.count == 5 {
max()
} else {
Manager.shared.removeCoin(coin: dataObject)
self.performSegue(withIdentifier: "addCoin", sender: self)
}
searchBar.text = ""
}
//Prepare for segue, pass removeCoinSegue Bool depending on remove or addCoin.
override func prepare(for segue: UIStoryboardSegue, sender: Any?) {
if segue.identifier == "addCoin" {
if let destinationVC = segue.destination as? RootViewController {
destinationVC.addCoinSegue = true
}
} else if segue.identifier == "addCoin" {
if let destinationVC = segue.destination as? RootViewController {
destinationVC.addCoinSegue = false
}
}
}
//Remove button action.
#objc func removeButtonAction(sender: UIButton!) {
if Manager.shared.coins.count == 1 {
removeAlert()
} else {
Manager.shared.removeCoin(coin: dataObject)
print(Manager.shared.coins)
print(dataObject)
searchBar.text = ""
self.removeButton.isHidden = true
DispatchQueue.main.async {
self.performSegue(withIdentifier: "removeCoin", sender: self)
}
}
}
//Search/Filter the struct from CGNames, display both the Symbol and the Name but use the ID as dataObject.
func filterStructForSearchText(searchText: String, scope: String = "All") {
if !searchText.isEmpty {
isSearching = true
filteredObject = CGNames.shared.coinNameData.filter {
// if you need to search key and value and include partial matches
// $0.key.contains(searchText) || $0.value.contains(searchText)
// if you need to search caseInsensitively key and value and include partial matches
$0.name.range(of: searchText, options: .caseInsensitive) != nil || $0.symbol.range(of: searchText, options: .caseInsensitive) != nil
}
.map{ $0.id }
} else {
isSearching = false
print("NoText")
}
}
//Running filter function when text changes.
func searchBar(_ searchBar: UISearchBar, textDidChange searchText: String) {
filterStructForSearchText(searchText: searchText)
if isSearching == true && filteredObject.count > 0 {
addButton.isHidden = false
dataObject = filteredObject[0]
selectionLabel.text = dataObject
if Manager.shared.coins.contains(dataObject) {
removeButton.isHidden = false
addButton.isHidden = true
} else {
removeButton.isHidden = true
addButton.isHidden = false
}
} else {
addButton.isHidden = true
removeButton.isHidden = true
selectionLabel.text = "e.g. btc/bitcoin"
}
}
override func viewDidLoad() {
super.viewDidLoad()
//Setup the UI.
self.view.backgroundColor = .gray
setupView()
}
override func viewDidLayoutSubviews() {
}
//Hide keyboard
override func touchesBegan(_ touches: Set<UITouch>, with event: UIEvent?) {
self.view.endEditing(true)
}
//Alerts
func removeAlert() {
let alertController = UIAlertController(title: "Can't Remove", message: "\(dataObject) can't be deleted, add another to delete \(dataObject)", preferredStyle: .alert)
alertController.addAction(UIAlertAction(title: "Okay", style: .default, handler: nil))
self.present(alertController, animated: true, completion: nil)
}
func Duplicate() {
let alertController = UIAlertController(title: "Duplicate", message: "\(dataObject) is already in your pages!", preferredStyle: .alert)
alertController.addAction(UIAlertAction(title: "Okay", style: .default, handler: nil))
self.present(alertController, animated: true, completion: nil)
}
func max() {
let alertController = UIAlertController(title: "Maximum Reached", message: "\(dataObject) can't be added, you have reached the maximum of 5 coins. Please delete a coin to add another.", preferredStyle: .alert)
alertController.addAction(UIAlertAction(title: "Okay", style: .default, handler: nil))
self.present(alertController, animated: true, completion: nil)
}
}
and here is the DataViewController
import UIKit
class DataViewController: UIViewController {
#IBOutlet weak var dataLabel: UILabel!
//Variables and Objects.
//The dataObject carries the chosen cryptocurrencies ID from the CoinGecko API to use to get the correct data to load on each object.
var dataObject = String()
//The DefaultCurrency (gbp, eur...) chosen by the user.
var defaultCurrency = ""
//The Currency Unit taken from the exchange section of the API.
var currencyUnit = CGExchange.shared.exchangeData[0].rates.gbp.unit
var secondaryUnit = CGExchange.shared.exchangeData[0].rates.eur.unit
var tertiaryUnit = CGExchange.shared.exchangeData[0].rates.usd.unit
//Index of the dataObject
var dataIndex = Int()
//Objects
let cryptoLabel = UILabel()
let cryptoIconImage = UIImageView()
let secondaryPriceLabel = UILabel()
let mainPriceLabel = UILabel()
let tertiaryPriceLabel = UILabel()
//Custom Fonts.
let customFont = UIFont(name: "AvenirNext-Heavy", size: UIFont.labelFontSize)
let secondFont = UIFont(name: "AvenirNext-BoldItalic" , size: UIFont.labelFontSize)
//Setup Functions
//Get the index of the dataObject
func getIndex() {
let index = CGPrices.shared.coinData.index(where: { $0.id == dataObject })!
dataIndex = index
}
//Label
func setupLabels() {
//cryptoLabel from dataObject as name.
cryptoLabel.text = CGPrices.shared.coinData[dataIndex].name
//Prices from btc Exchange rate.
let btcPrice = CGPrices.shared.coinData[dataIndex].current_price!
let dcExchangeRate = CGExchange.shared.exchangeData[0].rates.gbp.value
let secondaryExchangeRate = CGExchange.shared.exchangeData[0].rates.eur.value
let tertiaryExchangeRate = CGExchange.shared.exchangeData[0].rates.usd.value
let realPrice = (btcPrice * dcExchangeRate)
let secondaryPrice = (btcPrice * secondaryExchangeRate)
let tertiaryPrice = (btcPrice * tertiaryExchangeRate)
secondaryPriceLabel.text = "\(secondaryUnit)\(String((round(1000 * secondaryPrice) / 1000)))"
mainPriceLabel.text = "\(currencyUnit)\(String((round(1000 * realPrice) /1000)))"
tertiaryPriceLabel.text = "\(tertiaryUnit)\(String((round(1000 * tertiaryPrice) / 1000)))"
}
//Image
func getIcon() {
let chosenImage = CGPrices.shared.coinData[dataIndex].image
let remoteImageUrl = URL(string: chosenImage)
guard let url = remoteImageUrl else { return }
URLSession.shared.dataTask(with: url) { (data, response, err) in
guard let data = data else { return }
do {
DispatchQueue.main.async {
self.cryptoIconImage.image = UIImage(data: data)
}
}
}.resume()
}
override func viewDidLoad() {
super.viewDidLoad()
// for family in UIFont.familyNames.sorted() {
// let names = UIFont.fontNames(forFamilyName: family)
// print("Family: \(family) Font names: \(names)")
// }
// Do any additional setup after loading the view, typically from a nib.
self.setupLayout()
self.getIndex()
self.setupLabels()
self.getIcon()
}
override func viewWillAppear(_ animated: Bool) {
super.viewWillAppear(animated)
self.dataLabel!.text = dataObject
view.backgroundColor = .lightGray
}
}
Edit: CGPrices Class with getData method:
import Foundation
class CGPrices {
struct Coins: Decodable {
let id: String
let name: String
let symbol: String
let image: String
let current_price: Double?
let low_24h: Double?
//let price_change_24h: Double?
}
var coinData = [Coins]()
var defaultCurrency = ""
var coins = Manager.shared.coins
var coinsEncoded = ""
static let shared = CGPrices()
func encode() {
for i in 0..<coins.count {
coinsEncoded += coins[i]
if (i + 1) < coins.count { coinsEncoded += "%2C" }
}
print("encoded")
}
func getData(arr: Bool, completion: #escaping (Bool) -> ()) {
encode()
let urlJSON = "https://api.coingecko.com/api/v3/coins/markets?vs_currency=btc&ids=\(coinsEncoded)"
guard let url = URL(string: urlJSON) else { return }
URLSession.shared.dataTask(with: url) { (data, response, err) in
guard let data = data else { return }
do {
let coinsData = try JSONDecoder().decode([Coins].self, from: data)
self.coinData = coinsData
completion(arr)
} catch let jsonErr {
print("error serializing json: \(jsonErr)")
print(data)
}
}.resume()
}
func refresh(completion: () -> ()) {
defaultCurrency = UserDefaults.standard.string(forKey: "DefaultCurrency")!
completion()
}
}
I figured it out.
The problem was inside my getData method I was not updated the coins array:
var coinData = [Coins]()
var defaultCurrency = ""
var coins = Manager.shared.coins
var coinsEncoded = ""
static let shared = CGPrices()
func encode() {
for i in 0..<coins.count {
coinsEncoded += coins[i]
if (i+1)<coins.count { coinsEncoded+="%2C" }
}
print("encoded")
}
I needed to add this line in getData:
func getData(arr: Bool, completion: #escaping (Bool) -> ()) {
//Adding this line to update the array so that the URL is appended correctly.
coins = Manager.shared.coins
encode()
let urlJSON = "https://api.coingecko.com/api/v3/coins/markets?vs_currency=btc&ids=\(coinsEncoded)"
This would fix the finding nil in the DataViewController, but the app would still crash do to updating UI Elements on a background thread, as the segue was called inside the completion handler of the getData method. to fix this, I used DispatchQue.Main.Async on the segue inside the getData method in the addButton function, to ensure that everything is updated on the main thread, like so:
#objc func addButtonAction(sender: UIButton!) {
print("Button tapped")
if Manager.shared.coins.contains(dataObject) {
Duplicate()
} else if Manager.shared.coins.count == 5 {
max()
} else {
Manager.shared.addCoin(coin: dataObject)
print("starting")
CGPrices.shared.getData(arr: true) { (arr) in
print("complete")
print(CGPrices.shared.coinData)
//Here making sure it is updated on main thread.
DispatchQueue.main.async {
self.performSegue(withIdentifier: "addCoin", sender: self)
}
}
}
searchBar.text = ""
}
Thanks for all the comments as they helped me to figure this out, and I learned a lot in doing so. Hopefully this can help someone else in their thought process when debugging, as one can get so caught up in one area of a problem, and forget to take a step back and look to other areas.

How can I reuse a variable later on in Swift

I'm trying to capture a user input (textfield + button) and reuse the result later in the program but I don't know how to do that.
import UIKit
class ViewController: UIViewController {
#IBOutlet weak var resultLabel: UILabel!
#IBOutlet weak var moneyTextField: UITextField!
#IBAction func convert(_ sender: Any) {
let convertion:Double = Double(moneyTextField.text!)!
print(convertion)
}
override func viewDidLoad() {
super.viewDidLoad()
let url = URL(string: "https://www.x-rates.com/calculator/?from=EUR&to=USD&amount=1")!
let request = NSMutableURLRequest(url : url)
let task = URLSession.shared.dataTask(with: request as URLRequest) {
data, response, error in
var rateValue:Double = 0.0;
if let error = error {
print(error)
} else {
if let unwrappedData = data {
let dataString = NSString(data: unwrappedData, encoding: String.Encoding.utf8.rawValue)
var stringSeperator = "<span class=\"ccOutputRslt\">"
if let contentArray = dataString?.components(separatedBy: stringSeperator){
if contentArray.count > 0 {
stringSeperator = "<span"
let newContentArray = contentArray[1].components(separatedBy: stringSeperator)
if newContentArray.count > 0 {
rateValue = Double(newContentArray[0])!
print(newContentArray[0])
}
}
}
}
}
//
print("Rate is \(rateValue)");
DispatchQueue.main.sync(execute: {
self.resultLabel.text = "the value of the dollar is " + String(rateValue)
}
)}
task.resume()
}
}
What I want to do is take the let convertion and multiply it by rateValue at the end of the code. I tried different thing but without any results.
after the advice from Joakim Danielson
I did that :
import UIKit
class ViewController: UIViewController {
var fxRate: Double?
#IBOutlet weak var resultLabel: UILabel!
#IBOutlet weak var moneyTextField: UITextField!
#IBAction func convert(_ sender: Any) {
let convertion:Double = Double(moneyTextField.text!)!
print(convertion)
var convertedAmount = 0.0
if let rate = fxRate, let money = Double(moneyTextField.text) {
convertedAmount = rate * money
}
print(convertedAmount)
}
override func viewDidLoad() {
super.viewDidLoad()
// Do any additional setup after loading the view, typically from a nib.
let url = URL(string: "https://www.x-rates.com/calculator/?from=EUR&to=USD&amount=1")!
let request = NSMutableURLRequest(url : url)
let task = URLSession.shared.dataTask(with: request as URLRequest) {
data, response, error in
var rateValue:Double = 0.0;
if let error = error {
print(error)
} else {
if let unwrappedData = data {
let dataString = NSString(data: unwrappedData, encoding: String.Encoding.utf8.rawValue)
var stringSeperator = "<span class=\"ccOutputRslt\">"
if let contentArray = dataString?.components(separatedBy: stringSeperator){
if contentArray.count > 0 {
stringSeperator = "<span"
let newContentArray = contentArray[1].components(separatedBy: stringSeperator)
if newContentArray.count > 0 {
rateValue = Double(newContentArray[0])!
print(newContentArray[0])
rateValue = Double(newContentArray[0])!
self.fxRate = rateValue
}
}
}
}
}
//
print("Rate is \(rateValue)");
DispatchQueue.main.sync(execute: {
self.resultLabel.text = "the value of the dollar is " + String(rateValue)
}
)}
task.resume()
}
override func didReceiveMemoryWarning() {
super.didReceiveMemoryWarning()
// Dispose of any resources that can be recreated.
}
}
but I have the error : Cannot invoke initializer for type 'Double' with an argument list of type '(String?)' on line 26. Can you please help me? thx!
create a variable outside of your function
var anyVariableYouWantToAccessLater: Double?
And use this variable anywhere you want.
Since you're downloading the rate during viewDidLoad I am assuming this is what you want to keep.
Add a new property to the class
class ViewController: UIViewController {
var fxRate: Double?
...
In viewDidLoad update this property with the downloaded value
rateValue = Double(newContentArray[0])!
fxRate = rateValue
In the convert func (or wherever you want to use the rate)
#IBAction func convert(_ sender: Any) {
var convertedAmount = 0.0
if let rate = fxRate, let money = Double(moneyTextField.text ?? "0") {
convertedAmount = rate * money
}
print(convertedAmount)
}

Displaying Artwork for .MP3 file

I am trying to currently display the album artwork for a locally stored .MP3 track in an ImageView. Does anyone know how to fetch this artwork in Swift in order to accomplish this?
I have found this solution (iOS AVFoundation: How do I fetch artwork from an mp3 file?) but the code is written in Objective C. I simply want to grab the image embedded in my MP3 and display it in my ImageView.
I've looked at the API documentation for the MPMediaItemArtwork and found an example that also accomplishes what I am trying to accomplish in Objective C as well here(http://www.codeitive.com/0zHjkUjUWX/not-able-to-get-the-uiimage-from-mpmediaitempropertyartwork.html) but cannot come up with a solution. My code is as follows:
import UIKit
import AVFoundation
import MediaPlayer
class ViewController: UIViewController {
let audioPath:NSURL! = NSBundle.mainBundle().URLForResource("SippinOnFire", withExtension: "mp3")
#IBOutlet var artistImage: UIImageView!
#IBOutlet var trackLabel: UILabel!
#IBOutlet var artistLabel: UILabel!
#IBOutlet var sliderValue: UISlider!
var player:AVAudioPlayer = AVAudioPlayer()
#IBAction func play(sender: AnyObject) {
let audioInfo = MPNowPlayingInfoCenter.defaultCenter()
println(audioInfo)
player.play()
//println("Playing \(audioPath)")
let playerItem = AVPlayerItem(URL: audioPath)
let metadataList = playerItem.asset.metadata as! [AVMetadataItem]
for item in metadataList {
if let stringValue = item.value {
println(item.commonKey)
if item.commonKey == "title" {
trackLabel.text = stringValue as? String
}
if item.commonKey == "artist" {
artistLabel.text = stringValue as? String
}
if item.commonKey == "artwork" {
if let audioImage = UIImage(data: item.value as! NSData) {
let audioArtwork = MPMediaItemArtwork(image: audioImage)
println(audioImage.description)
}
}
}
}
}
#IBAction func pause(sender: AnyObject) {
player.pause()
}
#IBAction func stop(sender: AnyObject) {
player.stop()
player.currentTime = 0;
}
#IBAction func sliderChanged(sender: AnyObject) {
player.volume = sliderValue.value
}
override func viewDidLoad() {
super.viewDidLoad()
var error:NSError? = nil
player = AVAudioPlayer(contentsOfURL: audioPath!, error: &error)
player.volume = 0.5;
}
override func didReceiveMemoryWarning() {
super.didReceiveMemoryWarning()
// Dispose of any resources that can be recreated.
}
}
Here is a screen shot of my sample .mp3 file. As you can see there is indeed album artwork that is both visible in the "get info" section of Finder. I've also opened the .mp3 in my iTunes to make sure and have confirmed there is artwork in the "get info" section of it there as well as under the "artwork" tab.
However, when trying to use the commonKey to assign the image to my imageView I find that there is no commonKey for "artwork".
Thanks
Change your snippet of code into this (I already tested it):
I added println lines commented in places of interest, Feel free to uncomment in order to see what is happening.
for item in metadataList {
if item.commonKey == nil{
continue
}
if let key = item.commonKey, let value = item.value {
//println(key)
//println(value)
if key == "title" {
trackLabel.text = value as? String
}
if key == "artist" {
artistLabel.text = value as? String
}
if key == "artwork" {
if let audioImage = UIImage(data: value as! NSData) {
//println(audioImage.description)
artistImage.image = audioImage
}
}
}
}
UPDATE: A bit of clean up of this code
for item in metadataList {
guard let key = item.commonKey, let value = item.value else{
continue
}
switch key {
case "title" : trackLabel.text = value as? String
case "artist": artistLabel.text = value as? String
case "artwork" where value is NSData : artistImage.image = UIImage(data: value as! NSData)
default:
continue
}
}
UPDATE: For Swift 4
for item in metadataList {
guard let key = item.commonKey?.rawValue, let value = item.value else{
continue
}
switch key {
case "title" : trackLabel.text = value as? String
case "artist": artistLabel.text = value as? String
case "artwork" where value is Data : artistImage.image = UIImage(data: value as! Data)
default:
continue
}
}
edit/update Swift 4 or later:
import MediaPlayer
var nowPlayingInfo: [String: Any] = [:]
let playerItem = AVPlayerItem(url: url)
let metadataList = playerItem.asset.metadata
for item in metadataList {
switch item.commonKey {
case .commonKeyTitle?:
nowPlayingInfo[MPMediaItemPropertyTitle] = item.stringValue ?? ""
case .commonKeyType?:
nowPlayingInfo[MPMediaItemPropertyGenre] = item.stringValue ?? ""
case .commonKeyAlbumName?:
nowPlayingInfo[MPMediaItemPropertyAlbumTitle] = item.stringValue ?? ""
case .commonKeyArtist?:
nowPlayingInfo[MPMediaItemPropertyArtist] = item.stringValue ?? ""
case .commonKeyArtwork?:
if let data = item.dataValue,
let image = UIImage(data: data) {
nowPlayingInfo[MPMediaItemPropertyArtwork] = MPMediaItemArtwork(boundsSize: image.size) { _ in image }
}
case .none: break
default: break
}
}
let audioInfo = MPNowPlayingInfoCenter.default()
audioInfo.nowPlayingInfo = nowPlayingInfo
Note: You will have to invoke beginReceivingRemoteControlEvents() otherwise it will not work on the actual device. You will also need to set your app Background Modes (Audio and AirPlay) and set your AVAudioSession category to AVAudioSessionCategoryPlayback and set it active:
do {
try AVAudioSession.sharedInstance().setCategory(.playback, mode: .default, options: [.mixWithOthers, .allowAirPlay])
print("Playback OK")
try AVAudioSession.sharedInstance().setActive(true)
print("Session is Active")
} catch {
print(error)
}
Try this:
It appears that sometimes iOS 8 returns nil at first attempt of obtaining this info:
if let audioCenter = MPNowPlayingInfoCenter.defaultCenter(){
if let audioInfo = audioCenter.nowPlayingInfo{
if let artwork = audioInfo[MPMediaItemPropertyArtwork] as? MPMediaItemArtwork
{
var image: UIImage? = artwork.imageWithSize(artwork.bounds.size)
if image == nil {
image = artwork.imageWithSize(artwork.bounds.size);
}
if image != nil{
println("image loaded")
}
}
}
}