Swift 3 iterate over a nested Dictionary? - ios

Question

Okay, so, swift noob alert:
How do I do the simplest of iterations given the following array (I dont know what to call this shape: array, dictionary, object...)?
func showNotification(_ sender: [AnyHashable: Any]) { ... }
sender["actions"]:
Optional([{"text":"Confirm","type":"response"},{"text":"Decline","type":"response"},{"link":"https://www.stackoverflow.com","text":"Website","type":"info"}])
attempts:
if let result = sender["actions"] {
print("YES \(result)")
for action in result as! [String] {
print(action)
}
}
the above prints:
YES [{"text":"Confirm","type":"response"},{"text":"Decline","type":"response"},{"link":"https:\/\/www.stackoverflow.com","text":"Website","type":"info"}]
...however, returns the following error:
Could not cast value of type '__NSCFString' (0x1a7c28d50) to 'NSArray' (0x1a7c297c8)
The end goal here is to simply get to each one of the actions individually, ie:
{"text":"Confirm","type":"response"}
{"text":"Decline","type":"response"
ect...
Does Swift have a map function... FYI Im coming in from a Java and JavaScript world... swiftyjson seems a bit heavy for one loop.
Thanks, and as always any help and direction is appreciated!
edit:
This is the print via the param passed to the function sender:
sender: [AnyHashable("title"): title!, AnyHashable("message"): message, AnyHashable("message_id"): 0:1503511875428318%03300c3203300c32, AnyHashable("id"): 1497708240713, AnyHashable("actions"): [{"text":"Confirm","type":"response"},{"text":"Decline","type":"response"},{"link":"https:\/\/www.notifyd.com","text":"Website","type":"info"}], AnyHashable("aps"): {
"content-available" = 1;
}]

Answer 1

You want to decode the JSON String and then cast to an array of Dictionary:
if
// cast sender["actions"] to String
let actionsString = sender["actions"] as? String,
// decode data of string and then cast to Array<Dictionary<String, String>>
let actionsStringData = actionsString.data(using: .utf8),
let result = try JSONSerialization.jsonObject(with: actionsStringData, options: []) as? [[String : String]]
{
print("YES \(result)")
for action in result {
print(action)
}
}

Answer 2

Is it really true that what you've got here is an undecoded JSON string? In that case, Swift 4 makes this really easy:
struct S : Decodable {
let link : String?
let text : String
let type : String
}
if let acts = sender["actions"] as? String {
let data = acts.data(using: .utf8)!
if let arr = try? JSONDecoder().decode(Array<S>.self, from: data) {
arr.forEach {print($0)}
}
}
/*
S(link: nil, text: "Confirm", type: "response")
S(link: nil, text: "Decline", type: "response")
S(link: Optional("https://www.stackoverflow.com"), text: "Website", type: "info")
*/

Answer 3

There is something fishy going on here with the data. Let's treat the data with more care. Here is a method to get JSON from a JSON object, a JSON array, a Data object or a string.
enum JsonError: Error { case notJson; case notJsonArray }
func json(from any: Any?) throws -> Any {
if let json = any as? [String: Any] { return json }
if let json = any as? [Any] { return json }
if let data = any as? Data {
return try JSONSerialization.jsonObject(with: data)
}
if let string = any as? String, let data = string.data(using: .utf8) {
return try JSONSerialization.jsonObject(with: data)
}
throw JsonError.notJson
}
Now that I'm being more careful with the JSON object, I should get the what I want or know more about the error.
func showNotification(_ sender: [AnyHashable: Any]) {
do {
guard let result = try json(from: sender["actions"]) as? [Any] else {
throw JsonError.notJsonArray
}
print("YES \(result)")
for action in result {
print("Action: \(action)")
}
} catch {
// Do Something
}
}