Save Dictionary into NSUserDefaults Swift

Question

I have a Dictionary and i want to save it to NSUserDefaults(or something else so I can have access to my variables after i have terminated the app) , I found an example:

var saved = NSUserDefaults.standardUserDefaults()
let dict = ["Name": "Paul", "Country": "UK"]
saved.setObject(dict, forKey: "SavedDict")

But when i used it to mine Dictionary it didn't work. (maybe because my dictionary it's a little bit different)

My Dictionary is made like this:

 var userDictionary = [Int : Event]()

 struct Event {
        var sensorName: String
        var sensorType: String
        var sensorSub: String

    }

And i add elements like this:

userDictionary[value] = Event(sensorName: "first", sensorType: "Temp", sensorSub: "Third")

And here is what i tried to do so I can store it.

saved.setObject(userDictionary, forKey: "valueDictionary")

And I get this error:

Cannot convert value of type '[Int : SensorsView.Event]' to expected argument type 'AnyObject?'

To avoid this error I did this:

self.saved.setObject(self.userDictionary as? AnyObject, forKey: "valueDictionary")

But I can't retrieve what i saved

Unfortunately this question didn't help me after some comments i believe that the goal here is to convert my dictionary to Data (or something else) and after i retrieve it i convert it back to Dictionary

From the Doc: `The NSUserDefaults class provides convenience methods for accessing common types such as floats, doubles, integers, Booleans, and URLs. A default object must be a property list, that is, an instance of (or for collections a combination of instances of): NSData, NSString, NSNumber, NSDate, NSArray, or NSDictionary. If you want to store any other type of object, you should typically archive it to create an instance of NSData. For more details, see Preferences and Settings Programming Guide.` Event is not one of them, that's why we have in Objective-C to use the encode/decode. — Larme, Jul 10 '16 at 21:52
Thank you @Larme i will try to find some info about this convertion if you have something in mind to look please answer me. — mike vorisis, Jul 10 '16 at 21:55
For a small object like this one, you could use a `initWithDictionary:` method, and a `toDictionary`. Something that convert an`Event` object into `["Name":mySensorName,"Type":mySensorType, "Sub":mySensorSub"]` or something similar. — Larme, Jul 10 '16 at 21:59
I think http://stackoverflow.com/questions/25752433/swift-nsuserdefaults-not-saving-dictionary or http://stackoverflow.com/questions/25109813/saving-dictionary-into-nsuserdefaults may help — gurmandeep, Sep 09 '16 at 03:28

score 2 · Answer 1 · answered Sep 09 '16 at 00:09

Try to convert the data to NSData and then retrieve like so:

/// Save
NSUserDefaults.standardUserDefaults().setObject(NSKeyedArchiver.archivedDataWithRootObject(object), forKey: key)

/// Read
var data = NSUserDefaults.standardUserDefaults().objectForKey(key) as NSData
var object = NSKeyedUnarchiver.unarchiveObjectWithData(data) as [String: String]

score 0 · Answer 2 · edited May 23 '17 at 11:46

0

What i think is from the link below you will be able to store the Dictionary into NSUserDefaults

Swift NSUserDefaults not saving Dictionary? or

Saving dictionary into NSUserDefaults may help

edited May 23 '17 at 11:46

Community

1
1

answered Sep 09 '16 at 03:29

gurmandeep

1,227
1
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score 0 · Accepted Answer · answered Nov 06 '16 at 13:56

I managed to save my custom Dictionary using Realm! Instead of a struct I use a different class like this:

import RealmSwift


class Sensors : Object {


    dynamic var sensorName = ""
    dynamic var sensorType = ""
    dynamic var sensorSub = ""

}

and then I fill it like this:

    var useOfRealm = try! Realm() 
    var allSensors = useOfRealm.objects(Sensors.self)
    var saving = Sensors()
    func fillThis() {
    try! useOfRealm.write {

                saving.sensorName = "something"
                saving.sensorType = "something"
                saving.sensorSub = "something"

                useOfRealm.add(saving)
    }
}

Use the function with parameters so you can fill the 'Dictionary' Dynamically.

Use allSensors so you can retrieve everything that you want.

Save Dictionary into NSUserDefaults Swift

3 Answers3