ValueForKeyPath() returning something unexpected

Question

I am parsing this json:

{
"destination_addresses" : [ "Göteborg, Sverige" ],
"origin_addresses" : [ "Stockholm, Sverige" ],
"rows" : [
   {
      "elements" : [
         {
            "distance" : {
               "text" : "467 km",
               "value" : 466568
            },
            "duration" : {
               "text" : "4 timmar 34 min",
               "value" : 16468
            },
            "status" : "OK"
         }
      ]
   }
],
"status" : "OK"
}

Into an NSDictionary like this:

let dataDict = NSJSONSerialization.JSONObjectWithData(data.dataUsingEncoding(NSUTF8StringEncoding), options: nil, error: nil) as NSDictionary

let distance = dataDict.valueForKeyPath("rows.elements.distance.value")

Now, this works, no crashes or errors. But, I expect it to return 466568 but instead it returns this:

(
        (
        466568
    )
)

I dont know why and I cant use it and cant cast it into anything :(

There is another question similar to this, but the answer there didnt help me because Im not the one to change the json, Google is. So please no hate.

Answer 1

valueForKeyPath is returning a nested NSArray. You might want to cast it twice:

let distanceValue = ((distance as NSArray).objectAtIndex(0) as NSArray).objectAtIndex(0) as NSNumber
// or
let distanceValue = (distance as [NSArray])[0][0] as NSNumber

The distance value can't be directly accessed because valueForKeyPath does't implement a selector for array items.

Without valueForKeyPath:

let rows = dataDict.objectForKey("rows") as [NSDictionary]
let elements = rows[0]["elements"] as [NSDictionary]
let distance = elements[0]["distance"] as NSDictionary
let value = distance["value"] as NSNumber