UserDefaults are not working in my App. Please find the below code under AppDelegate file.
let sharingData = UserDefaults.init(suiteName: "group.macuser79.xxx");
sharingData?.set("vincenzo", forKey:"username");
sharingData?.synchronize();
In the InterfaceController of the app to Watch, to be able to retrieve the value so I did this:
override func awake(withContext context: Any?) {
let sharingData = UserDefaults.init(suiteName: "group.macuser79.xxx");
let username = sharingData?.object(forKey: "username");
print("Value username \(username)");
}
Please let me know, what I'm doing wrong!
In Swift3 UserDefaults made much smarter to obtained stored value. In below line, you are storing String value without specifying it!:
sharingData?.set("vincenzo", forKey:"username");
So, in order to get that, you need to write like below:
let username = sharingData?.string(forKey: "username");
print("Value username \(username)");
}
This is much more better context in getting values based on you Store.
Try this instead:
let defaults = UserDefaults.standard
defaults.set("group.macuser79.xxx", forKey:"username")
defaults.synchronize()
To access the store:
let defaults = UserDefaults.standard
let username = defaults.string(forKey: "username")
I admit that I haven't tried to init() my own UserDefaults instance before, but the standard instance of it, which is made into a singleton by iOS, is good practice to use.
Also, don't forget to unwrap the optional properly.
To set:
UserDefaults(suiteName: "group.macuser79.xxx")?.set("vincenzo", forKey: "username")
To access:
UserDefaults(suiteName: "group.macuser79.xxx")!.string(forKey: "username")
Related
I'd like to add data in the NSUserDefaults object for specific Username but I'm a little bit embarrassed I don't know how can I do it?
I started this way:
//Set data
let defaults = UserDefaults.standard
defaults.set(invnr, forKey: "Person")
defaults.synchronize()
//getData
let name = UserDefaults.standard.string(forKey: "Person")
print(name)
This way works, but for all users, I want to add data in session for specific username. Hope you help me. Thank you
Assuming you have
let username = "Blahblahblah"
So, let's try it in this way:
let defaults = UserDefaults.standard
defaults.set(invnr, forKey: "Person \(username)")
defaults.synchronize()
//getData
let name = UserDefaults.standard.string(forKey: "Person \(username)")
print(name)
I have a two step login process. On the first screen I save the FB user's details to UserDefaults.
When I load the second ViewController it is supposed to load the user's profile image and username (which I create using "fullname"). It actually works the second time I load the user but never the first time, is there some sort of delay? I already tried UserDefaults.standard.synchronize() but that does nothing. It even prints the details so I know it works...
let userName = fullName.replacingOccurrences(of: " ", with: "_")
UserDefaults.standard.setValue(userName, forKey: "username")
if let picture = result["picture"] as? NSDictionary , let data = picture["data"] as? NSDictionary, let url = data["url"] as? String {
UserDefaults.standard.setValue(url, forKey: "userFBPicURL")
let username = UserDefaults.standard.value(forKey: "username") as? String
let profileImage = UserDefaults.standard.value(forKey: "userFBPicURL") as? String
UserDefaults.standard.synchronize()
print ("Details are User:",username, "profileImage:",profileImage)
and in the new VC after self.performSegue(withIdentifier: "UsernameSegue", sender: self):
override func viewDidLoad() {
super.viewDidLoad()
if let username = UserDefaults.standard.value(forKey: "username") as? String {usernameTextfield.text = username}
if FBSDKAccessToken.current() != nil {loadFacebookProfileImage()}
}
I think you are setting the value to UserDefaults after performing segue or after the viewDidLoad gets called.
Steps to try find the issue:
Could you please try set breakpoint and see what goes first and what second?
Try printing from defaults right after you assign there.
Just try getting data not in ViewDidLoad but later. For example on button tap. Just to see if it's there for the 1st time too (but not only for the 2nd)
Question: where do you set the value to defaults?
PS: Also I wouldn't use UserDefaults for that, but yeah it's a different question.
Sorry, that can't provide an exact solution since it requires more info/code from your debugging. Please try the options above. Hope it helps.
I'm trying to save key value in the NSUserDefaults but is not been save. Here is my code:
func saveData() {
let userDefaults = NSUserDefaults.standardUserDefaults()
userDefaults.setObject("blablabla", forKey:"data")
userDefaults.synchronize()
}
Any of you knows why this data is not been save?
I'll really appreciate your help.
Swift 2.x:
According with Apple sources:
public func objectForKey(defaultName: String) -> AnyObject?
to retrieve your value you could use:
if let value = userDefaults.objectForKey("data") {
// do whatever you want with your value
// P.S. value could be numeric,string,..
}
I think you are doing it wrong, try like this:
let userDefaults = NSUserDefaults.standardUserDefaults()
userDefaults.setObject("blablabla", forKey:"data")
let defaults = NSUserDefaults.standardUserDefaults()
if let name = defaults.stringForKey("data") {
print(name)
}
You won't be able to access a string with dictionaryForKey because string is not a dictionary value type. Let me know if you need any further help.
You won't be able to access a string with 'dictionaryForKey' because a string is not a dictionary value type. You'll need to use:
if let savedString = userDefaults.stringForKey("data") {
print(savedString)
}
If you have any further questions feel free to let me know :)
How to delete data from NSUserDefaults? There is quite a few answers how to do it in Objective C, but how about Swift?
So I tried this:
let defaults = NSUserDefaults.standardUserDefaults()
defaults.removeObjectForKey("myKey")
Didn't work. Maybe what I really want to delete is not NSUserDefaults?
This is how I save data:
class MySavedData: NSObject, NSCoding {
var image: String
init(name: String, image: String) {
self.image = image
}
required init(coder aDecoder: NSCoder) {
image = aDecoder.decodeObjectForKey("image") as! String
}
func encodeWithCoder(aCoder: NSCoder) {
aCoder.encodeObject(image, forKey: "image")
}
}
class ViewController: <...> {
var myData = [MySavedData]() //Later myData gets modified and then function save() is called
func save() {
let savedData = NSKeyedArchiver.archivedDataWithRootObject(myData)
let defaults = NSUserDefaults.standardUserDefaults()
defaults.setObject(savedData, forKey: "myKey")
}
}
EDIT: Just to clear some things - data that is being saved is small (not even close to 100kb)
And maybe I am saving data not to NSUserDefaults (I am new to programming), so here is how I get it (load):
let defaults = NSUserDefaults.standardUserDefaults()
if let savedData = defaults.objectForKey("myData") as? NSData {
myData = NSKeyedUnarchiver.unarchiveObjectWithData(savedData) as! [UserLogin]
}
removeObjectForKey is the right way to go.
This will remove the value for the selected key. The following code sets a string value for a key in NSUserDefaults, prints it and then uses removeObjectForKey to remove and print the key value again. After removeObjectForKey the value is nil.
let prefs = NSUserDefaults.standardUserDefaults()
var keyValue = prefs.stringForKey("TESTKEY")
print("Key Value not set \(keyValue)")
let strHello = "HELLO WORLD"
prefs.setObject(strHello, forKey: "TESTKEY")
keyValue = prefs.stringForKey("TESTKEY")
print("Key Value \(keyValue)")
prefs.removeObjectForKey("TESTKEY")
keyValue = prefs.stringForKey("TESTKEY")
print("Key Value after remove \(keyValue)")
Returns:
Key Value not set nil
Key Value Optional("HELLO WORLD")
Key Value after remove nil
Update Swift 3:
let prefs = UserDefaults.standard
keyValue = prefs.string(forKey:"TESTKEY")
prefs.removeObject(forKey:"TESTKEY")
The code you have written will work fine, but NSUserDefaults synchronise at certain time interval.
As you want that should reflect in NSUserDefaults immediately ,so u need to write synchronise
let defaults = NSUserDefaults.standardUserDefaults()
defaults.removeObjectForKey("myKey")
defaults.synchronize()
Try This
NSUserDefaults.standardUserDefaults().removePersistentDomainForName(NSBundle.mainBundle().bundleIdentifier!)
for Swift 3
UserDefaults.standard.removePersistentDomain(forName: Bundle.main.bundleIdentifier!)
But this will clear all values from NSUserDefaults.careful while using.
Removing UserDefaults for key in swift 3, based upon the top answer, just slightly different syntax:
UserDefaults.standard.removeObject(forKey: "doesContractExist")
Swift 4.x Remove all key in UserDefaults
let defaults = UserDefaults.standard
let dictionary = defaults.dictionaryRepresentation()
dictionary.keys.forEach
{ key in defaults.removeObject(forKey: key)
}
Use following for loop:
for key in NSUserDefaults.standardUserDefaults().dictionaryRepresentation().keys {
NSUserDefaults.standardUserDefaults().removeObjectForKey(key.description)
}
I would go for a solution which setting the value to nil for a key.
Swift 3
UserDefaults.standard.set(nil, forKey: "key")
Swift 2.x
NSUserDefaults.standardUserDefaults().setValue(nil, forKey: "key")
NOTE: that is a clear and straight statement, but bear in mind there is a limit to store information in NSUserDefaults, it is definitely not the right place to store large binary files (like e.g. images) – for that there is a Documents folder. however it is not defined how big the var image: String which you encode/decode.
To nuke all UserDefaults keys, you can use the following code in Swift 3.x:
UserDefaults.standard.removePersistentDomain(forName: Bundle.main.bundleIdentifier!)
In Swift 5.0, iOS 15 below single line of code is enough.
UserDefaults.standard.dictionaryRepresentation().keys.forEach(defaults.removeObject(forKey:))
Or try this
if let appDomain = Bundle.main.bundleIdentifier {
UserDefaults.standard.removePersistentDomain(forName: appDomain)
}
func remove_pref(remove_key : String){
UserDefaults.standard.removeObject(forKey: remove_key)
UserDefaults.standard.synchronize()
}
Update code for Swift :
Used below line of code to Delete key values for NSUserDefaults in Swift
UserDefaults.standard.setValue(nil, forKey: "YouEnterKey")
I'm trying to save a variable in Xcode so that it saves even after the app has closed, how ever when I access it I do it from a several different classes and files, and I change the value of the variable when I access it. Therefore similar threads do not completely apply, the value to be stored is a string and here is the code I have up until now:
var defaults: NSUserDefaults = NSUserDefaults.standardUserDefaults()
defaults.setObject(Token, forKey: "") as! String
I believe this is the correct format, but I don't know how to call it to change it because when I try I get an error message saying expected declaration.
Anyway any help would be very much appreciated.
First of all you have to specify an unique key to store the variable (in the example MyKey ).
In AppDelegate > applicationDidFinishLaunching register the key with a default value.
The benefit is you can use a non-optional variable and you have a defined default value.
let defaults = UserDefaults.standard
let defaultValue = ["MyKey" : ""]
defaults.register(defaults: defaultValue)
Now you can from everywhere read the value for the key
let defaults = UserDefaults.standard
let token = defaults.string(forKey: "MyKey")
and save it
let defaults = UserDefaults.standard
defaults.set(token, forKey: "MyKey")
Swift 3
(thanks to vadian's answer)
In AppDelegate > applicationDidFinishLaunching :
let defaults = UserDefaults.standard
let defaultValue = ["myKey" : ""]
defaults.register(defaults: defaultValue)
to save a key:
let defaults = UserDefaults.standard
defaults.set("someVariableOrString", forKey: "myKey")
defaults.synchronize()
to read a key:
let defaults = UserDefaults.standard
let token = defaults.string(forKey: "myKey")
Let's say you have a string variable called token
To save/update the stored value on the device:
NSUserDefaults.standardUserDefaults().setObject(token, forKey: "mytoken")
NSUserDefaults.standardUserDefaults().synchronize()
In the code above I made sure to give the key a value ("mytoken"). This is so that we later can find it.
To read the stored value from the device:
let token = NSUserDefaults.standardUserDefaults().objectForKey("mytoken") as? String
Since the method objectForKey returns an optional AnyObject, I'll make sure to cast it to an optional String (optional meaning that it's either nil or has a value).
Add default.synchronize() after setting value.