So I am new to using Parse and having some issues with posting a message through the back-end. I am able to set up a user account but when I try to submit the post I am getting an error that says..."fatal error: unexpectedly found nil while unwrapping an Optional value" ...?
Here is my code:
class ComposeViewController: UIViewController {
#IBOutlet var travelTextView: UITextView!
#IBOutlet var charRemainingLabel: UILabel!
override func viewDidLoad() {
super.viewDidLoad()
// Do any additional setup after loading the view.
}
override func didReceiveMemoryWarning() {
super.didReceiveMemoryWarning()
// Dispose of any resources that can be recreated.
}
#IBAction func sendPost(sender: AnyObject) {
var travelPost:PFObject = PFObject(className: "travelposts")
travelPost["content"] = travelTextView.text
travelPost["poster"] = PFUser.currentUser()
travelPost.saveInBackgroundWithTarget(nil, selector: nil)
self.navigationController?.popToRootViewControllerAnimated(true)
}
you cannot pass nil for selector.
travelPost.saveInBackgroundWithTarget(nil, selector: nil);
do this to just save the object.
travelPost.saveInBackground();
But you want to get notified when the object is saved use
Related
I'm learning how to program and am playing with a Swift project in Xcode. The main storyboard has two view controllers. The first view controller is simply called ViewController and the second view controller is called HelpScreenViewController.
In ViewController I have a "help" button that switches the user to HelpScreenViewController. This button uses a segue called "goToHelpScreenSegue".
In HelpScreenViewController I have three buttons:
"Close" button to dismisses the view (no segue used)
"Send Feedback" button to generate a new email in the Mail app (no segue used)
"Reset Game" button to call a function that is coded within the first ViewController. This third button uses a segue called "resetGameSegue".
What I'm trying to do is...
...Get the "Reset Game" button on the HelpScreenViewController to reset the game by calling a function that's coded within the first view controller.*
To try and get this to work the way I want, I've used the following code:
WITHIN first main ViewController
import UIKit
import iAd
import AdSupport
import AVFoundation //audio
import GameplayKit
class ViewController: UIViewController, ADBannerViewDelegate, MyResetGameProtocol {
#IBOutlet weak var Banner: ADBannerView!
#IBOutlet weak var buttonA: UIButton!
#IBOutlet weak var buttonB: UIButton!
#IBOutlet weak var buttonC: UIButton!
#IBOutlet weak var buttonD: UIButton!
#IBOutlet weak var labelQuestion: UILabel!
#IBOutlet weak var labelScore: UILabel!
#IBOutlet weak var labelTotalQuestionsAsked: UILabel!
#IBOutlet weak var labelFeedback: UILabel!
#IBOutlet weak var buttonNext: UIButton!
var score :Int! = 0
var totalquestionsasked :Int! = 0
var allEntries : NSArray!
var shuffledQuestions: [AnyObject]!
var nextQuestion = -1
var currentCorrectAnswerIndex : Int = 0
var audioPlayer = AVAudioPlayer()
override func viewDidLoad() {
super.viewDidLoad()
// Do any additional setup after loading the view, typically from a nib.
self.Banner?.delegate = self
self.Banner?.hidden = true
LoadAllQuestionsAndAnswers()
if #available(iOS 9.0, *) {
shuffledQuestions = GKRandomSource.sharedRandom().arrayByShufflingObjectsInArray(allEntries as [AnyObject])
nextQuestion++
LoadQuestion(nextQuestion)
// Fallback on earlier versions
}else{
let randomNumber = Int(arc4random_uniform(UInt32(allEntries.count)))
LoadQuestionPreiOS9(randomNumber)
}
LoadScore()
AdjustInterface()
}
override func didReceiveMemoryWarning() {
super.didReceiveMemoryWarning()
// Dispose of any resources that can be recreated.
}
override func prepareForSegue(segue: UIStoryboardSegue, sender: AnyObject?) {
let viewController = segue.destinationViewController as! HelpScreenViewController
viewController.controller = self
}
func ResetGame() {
PlaySoundReset()
score = 0
totalquestionsasked = 0
SaveScore()
LoadScore()
}
func PlaySoundReset()
{
let alertSound = NSURL(fileURLWithPath: NSBundle.mainBundle().pathForResource("pcbeep", ofType: "wav")!)
do {
audioPlayer = try AVAudioPlayer(contentsOfURL: alertSound)
} catch {
}
audioPlayer.prepareToPlay()
audioPlayer.play()
}
func SaveScore()
{
let defaults = NSUserDefaults.standardUserDefaults()
defaults.setInteger(score, forKey: "Score")
defaults.setInteger(totalquestionsasked, forKey: "Out of")
}
func LoadScore()
{
let defaults = NSUserDefaults.standardUserDefaults()
score = defaults.integerForKey("Score")
totalquestionsasked = defaults.integerForKey("Out of")
labelScore.text = "Score: \(score)"
labelTotalQuestionsAsked.text = "out of \(totalquestionsasked)"
}
and so on....
WITHIN the second HelpScreenViewController
import UIKit
protocol MyResetGameProtocol {
func ResetGame()
}
class HelpScreenViewController: UIViewController, MyResetGameProtocol {
var controller: MyResetGameProtocol? // reference to the delegate alias First Controller
override func viewDidLoad() {
super.viewDidLoad()
// Do any additional setup after loading the view.
}
override func didReceiveMemoryWarning() {
super.didReceiveMemoryWarning()
// Dispose of any resources that can be recreated.
}
/*
// MARK: - Navigation
// In a storyboard-based application, you will often want to do a little preparation before navigation
override func prepareForSegue(segue: UIStoryboardSegue, sender: AnyObject?) {
// Get the new view controller using segue.destinationViewController.
// Pass the selected object to the new view controller.
}
*/
#IBAction func SendFeedback(sender: AnyObject) {
UIApplication.sharedApplication().openURL(NSURL(string: "mailto:feedback#felice.ws?")!)
}
#IBAction func DismissView(sender: AnyObject) {
self.dismissViewControllerAnimated(true, completion: nil) }
#IBAction func buttonResetGame(sender: AnyObject) {
controller.ResetGame()
}
}
Now, at the moment with the above code what happens is that if the user taps the "help" button in the first main ViewController (i.e. goToHelpScreenSegue), not only does it take the user to the help screen, but it also calls the function I want activated when the user taps on the "Reset Game" button instead. That is, at the moment, it's the "help" button that resets the game before taking the user to the help screen.
Now, within the help screen, the first two buttons work normally (but they're not using segues). Tapping on the third button (the Reset Game one) simply returns the user back to the main screen. It doesn't call the function, doesn't reset the game.
I've lost count of the times I've changed the code around to try and get it to work right, but I've obviously missed something really obvious.
In particular, I've tried using the following code instead within the main ViewController:
override func prepareForSegue(segue: UIStoryboardSegue?, sender: AnyObject?) {
if segue?.identifier == "resetGameSegue" {
let viewController = segue!.destinationViewController as! HelpScreenViewController
viewController.controller = self
}
However, this results in nothing happening. What I mean is that the button on the main screen works properly (taking the user to the help screen and not incorrectly calling the resetGame function). And, within the help screen the first two buttons work as expected, but the "Reset Game" button just returns the user to the first screen but without calling the ResetGame function.
I also tried removing the IBActions from both my code and the connections inspector for the "Reset Game" button, but that made no difference either.
Any assistance would be most appreciated as I'm just not getting it! :(
I'm agree with MikeG, that you should probably learn about how delegates should be implemented. But the thing you're doing wrong inside this code is that you're not actually calling ResetGame() function on your delegate. Try to implement your #IBAction function in this way:
#IBAction func buttonResetGame(sender: AnyObject) {
controller?.ResetGame()
}
And yeah, if I understand your logic correctly your HelpScreenViewController should not implement MyResetGameProtocol cause your ViewController is the one who's implementing it.
My question is about the UISlider. I managed to implement everything but i don't know how i can save its status.
Ive looked everywhere but al the posts are in older versions of swift/xcode. So the question is how do i save its status so that when i go to another view and then come back the status is still the same.
Thanks very much!
import UIKit
class SettingsViewController: UIViewController {
var sequeInt = 0
let savedWordLength = NSUserDefaults.standardUserDefaults()
override func viewDidLoad() {
super.viewDidLoad()
}
override func didReceiveMemoryWarning() {
super.didReceiveMemoryWarning()
// Dispose of any resources that can be recreated.
}
#IBOutlet weak var wordLength: UISlider!
#IBOutlet weak var wordLengthValue: UILabel!
var selectedValue: Int = 5
#IBAction func valueChanged(sender: UISlider) {
selectedValue = Int(sender.value)
savedWordLength.setInteger(selectedValue, forKey: "myInt")
let ourInt = savedWordLength.integerForKey("myInt")
sequeInt = ourInt
print (sequeInt)
wordLengthValue.text = String(ourInt)
}
UISlider value property is a Float so you can use NSUserDefault's method setFloat to save its value and retrieve it next time your view appears using NSUserDefaults method floatForKey.
to save it:
NSUserDefaults.standardUserDefaults().setFloat(sender.value, forKey: "wordLength")
load it:
override func viewWillAppear(animated: Bool) {
wordLength.setValue(NSUserDefaults.standardUserDefaults().floatForKey("wordLength"), animated: false)
}
Follow these steps.
In your view will appear.
fontSlider.setValue(UserDefaults.standard.float(forKey: "slider_value"), animated: false)
Take another outlet from storyBoard as "editingDidEnd".
In that function:
UserDefaults.standard.set(fontSlider.value, forKey: "slider_value")
And finally in your ValueChanged Outlet.
UserDefaults.standard.set(fontSlider.value, forKey: "slider_value")
my app needs from the user to log in. okay i connected my app to parse, and in the login view controller i wrote these codes
import UIKit
class SigninPageViewController: UIViewController {
#IBOutlet weak var userNameTextField: UITextField!
#IBOutlet weak var userEmailTextField: UITextField!
#IBOutlet weak var userPasswordTextField: UITextField!
override func viewDidLoad() {
super.viewDidLoad()
// Do any additional setup after loading the view.
}
override func didReceiveMemoryWarning() {
super.didReceiveMemoryWarning()
// Dispose of any resources that can be recreated.
}
#IBAction func doneButtonTapped(sender: AnyObject) {
let userEmail = userEmailTextField.text;
let userPassword = userPasswordTextField.text;
PFUser.logInWithUsernameInBackground(userEmail, password: userPassword) {
(user: PFUser?, error: NSError?) -> Void in
if user != nil {
// Login is successful
NSUserDefaults.standardUserDefaults().setBool(true, forKey:"isUserLoggedIn");
NSUserDefaults.standardUserDefaults().synchronize();
self.dismissViewControllerAnimated(true, completion: nil);
} else {
println("Could not find user")
}
}
}
}
the problem is when i tried my app and tried to write the wrong email and the wrong password, the app let me log in without checking if the user is exist or not and without printing line (Could not find user). So the question here is how to let my app check if the user is exist or not, and do not let anonymous users in.
You could establish your own requirements for logging in. If you do a fetch for the user with the email address they entered, you can allow log in only if the email address exists. If it doesn't, just send the user an alert, and don't go through with the login.
I have my code so it puts an annotation on the map each time the user clicks a button, but when the user closes out of the app, the annotation disappears. How do I make it so the annotations stays on the map even when the user closes the app? Below is my code:
import UIKit
import CoreLocation
import MapKit
class UpdateCar: UIViewController, CLLocationManagerDelegate {
#IBOutlet weak var mapView: MKMapView!
#IBOutlet weak var lblLocation: UILabel!
var locationManager = CLLocationManager()
var myPosition = CLLocationCoordinate2D()
override func viewDidLoad() {
super.viewDidLoad()
// Do any additional setup after loading the view, typically from a nib.
locationManager.delegate = self
locationManager.requestWhenInUseAuthorization()
locationManager.startUpdatingLocation()
}
override func didReceiveMemoryWarning() {
super.didReceiveMemoryWarning()
// Dispose of any resources that can be recreated.
}
func locationManager(manager: CLLocationManager!, didUpdateToLocation newLocation: CLLocation!, fromLocation oldLocation: CLLocation!) {
println("Updating Car Location \(newLocation.coordinate.latitude) , \(newLocation.coordinate.longitude) ")
myPosition = newLocation.coordinate
locationManager.stopUpdatingLocation()
lblLocation.text = "\(newLocation.coordinate.latitude) , \(newLocation.coordinate.longitude)"
}
#IBAction func findUserLocationAndDropPin(sender: UIButton) {
var userLocationCoordinates = CLLocationCoordinate2DMake(locationManager.location.coordinate.latitude, locationManager.location.coordinate.longitude)
var pinForUserLocation = MKPointAnnotation()
pinForUserLocation.coordinate = userLocationCoordinates
mapView.addAnnotation(pinForUserLocation)
mapView.showAnnotations([pinForUserLocation], animated: true)
}
}
You have to save it in a persistent store.
Few options:
CoreData, the native way of saving data, recommended, not too easy
NSUserDefaults, usually thought for small stuff, also native, not recommended, very easy though
Another API for managing a persistent store like Realm (similar to CoreData, a little easier but not native)
//when I need to save for example, the last date on which the user login my app will use the setObject function, this will save a value ("10/05/2015") in the "lastlogin" key
var lastLogin = "10/05/2015"
NSUserDefaults.standarUserDefaults().setObject(lastLogin, forkey: "lastLogin")
//And when I need to retrieve the stored value in the "lastlogin" key which I use is "objectForKey" function
NSUserDefaults.standarUserDefaults().objectForKey("lastLogin")
see following link:
https://developer.apple.com/library/mac/documentation/Cocoa/Reference/Foundation/Classes/NSUserDefaults_Class/index.html#//apple_ref/occ/instm/NSUserDefaults/setObject:forKey:
I'm pretty new to coding in Swift and I'm not too sure what's happening here - can anyone help?
Thanks
import UIKit
class SecondViewController: UIViewController {
var toDoItems:[String] = []
#IBOutlet weak var toDoItem: UITextField!
#IBAction func addItem(sender: AnyObject) {
toDoItems.append(toDoItem.text)
fatal error: unexpectedly found nil while unwrapping an Optional value
(lldb)
println(toDoItems)
}
override func viewDidLoad() {
super.viewDidLoad()
// Do any additional setup after loading the view, typically from a nib.
}
override func didReceiveMemoryWarning() {
super.didReceiveMemoryWarning()
// Dispose of any resources that can be recreated.
}
}
Most likely, your IBOutlet, toDoItem, was not bound successfully to a UITextField in Interface Builder. Check the outlets for your text field in Interface Builder and make sure it's hooked up successfully.
If the outlet is hooked up properly, another candidate source of this problem is the instantiation of the view controller itself. If you instantiated it programmatically (e.g. SecondViewController() instead of storyboard.instantiateViewControllerWithIdentifier(...)), that would also result in this error.