Save a tuple in NSUserDefaults

Question

I\'m using a tuple to store something like this.

var accessLavels: (hasInventoryAccess: Bool, hasPayrolAccess: Bool)
accessLavels = (hasInventoryAccess: true         


        

Answer 1

I encountered a similar scenario trying to encode a tuple with NSCoder. The way I am solving it is by manually converting the tuple to a Dictionary. This is not a great solution as the keys need to be changed in several places if the tuple ever changes.

I had a nested enum in my tuple and gave it a base type (String) from which I converted the raw value. It was a little extra work but thankfully yours is only primitives.

# SerializeableTuple.swift

typealias AccessTuple = (hasInventoryAccess: Bool, hasPayrolAccess: Bool)
typealias AccessDictionary = [String: Bool]

let InventoryKey = "hasInventoryAccess"
let PayrollKey = "hasPayrollAccess"

func serializeTuple(tuple: AccessTuple) -> AccessDictionary {
    return [
        InventoryKey : tuple.hasInventoryAccess,
        PayrollKey : tuple.hasPayrolAccess
    ]
}

func deserializeDictionary(dictionary: AccessDictionary) -> AccessTuple {
    return AccessTuple(
        dictionary[InventoryKey] as Bool!,
        dictionary[PayrollKey] as Bool!
    )
}

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# Encoding / Decoding

var accessLavels: AccessTuple = (hasInventoryAccess: true, hasPayrolAccess: false)

// Writing to defaults
let accessLevelDictionary = serializeTuple(accessLavels)
NSUserDefaults.standardUserDefaults().setObject(accessLevelDictionary, forKey: "AccessLevelKey")

// Reading from defaults
let accessDic = NSUserDefaults.standardUserDefaults().dictionaryForKey("AccessLevelKey") as AccessDictionary
let accessLev = deserializeDictionary(accessDic)