Extract Value from Locksmith with SwiftyJson - ios

Question

I'm trying the value of an access token in Swift. I'm loading the token using Locksmith like so:
let (dictionary, error) = Locksmith.loadDataForUserAccount("userAccount")
This returns the following in the console:
Optional({
"access_token" = 123123123123123;
})
I'm using SwiftyJSON to extract the value of the access token
var access_token = dictionary["access_token"].stringValue
I'm getting the following error:
'NSDictionary?' does not have a member named 'subscript'
Any idea why?

Answer 1

LockSmith returns (NSDictionary?, NSError?):
public class func loadDataForUserAccount(userAccount: String, inService service: String = LocksmithDefaultService) -> (NSDictionary?, NSError?)
So, in your case dictionary itself is Optional:
Try:
var access_token = dictionary?["access_token"] as? String
Here, access_token is String?, it can be nil. If you want to store it to AnyObject variable, you must unwrap it. For example, using "Optional Binding":
if let token = access_token {
// Here, `token` is `String`, while `access_token` is `String?`
self.access_token = token
}
Or more directly:
if let access_token = dictionary?["access_token"] as? String {
// Here, access_token is `String`, not `String?`
self.access_token = token
}
else {
// error handling...
}
BTW, If you want to use SwiftyJSON, you should create JSON object from dictionary.
if let dict = dictionary {
var json = JSON(dict)
var access_token = json["access_token"].stringValue
}

Answer 2

As described at your 'NSDictionary?' Dictionary is an optional. You have to unwrap your optional before extracting stringValue from it. You can safely unwrap it using if let:
Edit
taking a hint from Rintaro as mentioned by him LockSmith returns an optional Dictionary so you need to first unwrap your dictionary and them you can unwrap access_token key value
if let dictionary = dictionary {
if let access_token = dictionary["access_token"] as? Int { // or as? String
println(access_token)
} else {
println(false)
}
} else {
println(false)
}
or if it returns a [String:String] Dictionary there is no need to cast the value to String
if let dictionary = dictionary {
if let access_token = dictionary["access_token"] {
println(access_token)
} else {
println(false)
}
} else {
println(false)
}