ckraider ckraider - 1 month ago 6
iOS Question

How to format date in Swift that similarly matches Json?

I am having trouble generating Date objects that match the json output. In http://chartapi.finance.yahoo.com/instrument/1.0/aapl/chartdata;type=quote;range=1y/json - the dates are in the following format "Date": 20151013. In order to get 2015-10-13, first I use Alamofire & SwiftJSON in my API call and JSON parsing. Here are some relevant lines from my code:

let dateInteger = subJson["Date"].int
if dateInteger != nil {
let editedDateInt = dateInteger!
let dateString = NSMutableString(string: "\(editedDateInt)")
dateString.insert("-", at: 4)
dateString.insert("-", at: 7)
chartpoint.date = Formatters.sharedInstance.dateFromString(key: dateString as String) }

// date extension
public class Formatters {
public static let sharedInstance = Formatters()
private let dateKeyFormatter = DateFormatter()
init() { dateKeyFormatter.dateFormat = "yyyy-MM-dd" }

public func dateFromString(key: String?) -> Date? {
guard let key = key else { return nil }
return dateKeyFormatter.date(from: key) }


Problem is the output came up Optional(2015-10-12 16:00:00 +0000). Not quite 2015-10-13 that I was expecting. How do I fix this? Is this related to user's Locale or TimeZone?

Answer

Check this out

Swift 3.0

let dateFromServer = "20151013"    
let dateFormatter = DateFormatter()
dateFormatter.dateFormat = "yyyyMMdd"
dateFormatter.timeZone = TimeZone(abbreviation: "GMT")
let date = dateFormatter.date(from: dateFromServer)
dateFormatter.dateFormat = "yyyy-MM-dd"
let finalDate = dateFormatter.string(from: date!)
print(finalDate)

Output:

2015-10-13

As suggested by @rmaddy changed the format style form YYYY to yyyy.