CrashSpace Sign JSON parsing in Swift, using struct

CrashSpaceSignJsonParseStruct.swift

//: CrashSpace Sign JSON parsing in Swift, using struct

import Cocoa
import Foundation

struct ButtonPress {
    let id: String
    let msg: String
    let diff_mins: Int
    let date: String
    let date_epoch: String
    let type: String
}

extension ButtonPress {
    // 'json' is dictionary where key is string, value is any
    init?(json: [String: Any]) {
        guard let id = json["id"] as? String,
            let msg = json["msg"] as? String,
            let diff_mins = json["diff_mins_max"] as? Int,
            let date = json["date"] as? String,
            let date_epoch = json["date_epoch"] as? String,
            let type = json["type"] as? String
        else {
                return nil
        }
        self.id = id
        self.msg = msg
        self.diff_mins = diff_mins
        self.date = date
        self.date_epoch = date_epoch
        self.type = type
    }
}

// array to hold our future list of ButtonPress objects
var buttonPresses = [ButtonPress]()


let urlString = "https://crashspacela.com/sign2/json/";

let url = URL(string: urlString)

URLSession.shared.dataTask(with:url!) { (data, response, error) in
    if error != nil {
        print("oh no \(error)")
    } else {
        print("hi there; we got server response")
        do {
            
            let parsedData = try JSONSerialization.jsonObject(with: data!, options: .allowFragments) as! [Any]
            
            print("all items:");
            print("-------------");

            for item in parsedData {
                let item = item as! [String:Any] // recast as array w/ key:string, val:any
                let id = item["id"] as! String
                let msg = item["msg"] as! String
                let diff_mins = item["diff_mins_max"] as! Int
                print("  item: id:\(id), msg:\(msg), diff_mins:\(diff_mins)")
            }
            
            // from https://developer.apple.com/swift/blog/?id=37
            // convert json-ish data to struct, using extension
            for item in parsedData {
                let item = item as! [String:Any]
                if let buttonPress = ButtonPress(json: item) {
                    buttonPresses.append(buttonPress)
                }
            }
            
            print("\nbuttonPress structs");
            print("-------------");
            
            for b in buttonPresses {
                print("buttonPress: \(b.id) '\(b.msg)' for \(b.diff_mins) minutes at \(b.date)")
            }
            
        } catch let error as NSError {
            print(error)
        }
    }
    
    }.resume()


// in playground, loop forever so the task above completes
var waiting = true
while( waiting ) {
    sleep(10)
    print("sleeping...")
}