Swift 3 JSON Bug? - json

Question

I can't seem to compile my code no matter how much I fiddle with it. I think I need another perspective.
At "let image = data["images"] as! [String : AnyObject]"
xcode keeps telling me "Cannot subscript a value of type '[[String : AnyObject]]' with an index of type 'String'"
func retreiveInstagramMedia() {
let token = user?.token
let urlString = "https://api.instagram.com/v1/users/self/media/recent/?access_token=\(token!)"
let url = URL(string: urlString)
URLSession.shared.dataTask(with: url!, completionHandler: {
(data, response, error) in
if(error != nil){
print("error")
}else{
do{
let json = try JSONSerialization.jsonObject(with: data!, options:.allowFragments) as! [String : AnyObject]
if let data = json["data"] as? [[String : AnyObject]] {
let image = data["images"] as! [String : AnyObject]
let standardResolution = image["standard_resolution"] as! [String : AnyObject]
let url = standardResolution["url"] as! String
print(url)
}
OperationQueue.main.addOperation({
self.tableView.reloadData()
})
}catch let error as NSError{
print(error)
}
}
}).resume()
}

Answer 1

As Martin said, your data is an array of dictionaries. So iterate through those dictionaries:
if let arrayOfData = json["data"] as? [[String : Any]] {
for individualData in arrayOfData {
if let image = individualData["images"] as? [String : Any],
let standardResolution = image["standard_resolution"] as? [String : Any],
let url = standardResolution["url"] as? String {
// now do something with URL
print(url)
}
}
}
I'd suggest you avoid using ! to force cast/unwrap. When dealing with data from remote sources, you should more gracefully handle situations where one of these subscripts fail to retrieve what you expect they would.

Answer 2

First of all in Swift 3 a JSON dictionary is [String:Any]
Your mistake (developer bug) is to use the array data as the index variable of the loop.
Replace the underscore with anItem and get the image with anItem["images"]
let json = try JSONSerialization.jsonObject(with: data!) as! [String : Any]
if let data = json["data"] as? [[String : Any]] {
for anItem in data {
let image = anItem["images"] as! [String : Any]
let standardResolution = image["standard_resolution"] as! [String : Any]
let url = standardResolution["url"] as! String
print(url)
}
}
Note: The key images implies multiple items so the value could be also an array.