In the future the format might need to be changed which could be a small head ache having date.dateFromISO8601 calls everywhere in an app. Use a class and protocol to wrap the implementation, changing the date time format call in one place will be simpler. Use RFC3339 if possible, its a more complete representation. DateFormatProtocol and DateFormat is great for dependency injection.
class AppDelegate: UIResponder, UIApplicationDelegate {
internal static let rfc3339DateFormat = "yyyy-MM-dd'T'HH:mm:ssZZZZZ"
internal static let localeEnUsPosix = "en_US_POSIX"
}
import Foundation
protocol DateFormatProtocol {
func format(date: NSDate) -> String
func parse(date: String) -> NSDate?
}
import Foundation
class DateFormat: DateFormatProtocol {
func format(date: NSDate) -> String {
return date.rfc3339
}
func parse(date: String) -> NSDate? {
return date.rfc3339
}
}
extension NSDate {
struct Formatter {
static let rfc3339: NSDateFormatter = {
let formatter = NSDateFormatter()
formatter.calendar = NSCalendar(calendarIdentifier: NSCalendarIdentifierISO8601)
formatter.locale = NSLocale(localeIdentifier: AppDelegate.localeEnUsPosix)
formatter.timeZone = NSTimeZone(forSecondsFromGMT: 0)
formatter.dateFormat = rfc3339DateFormat
return formatter
}()
}
var rfc3339: String { return Formatter.rfc3339.stringFromDate(self) }
}
extension String {
var rfc3339: NSDate? {
return NSDate.Formatter.rfc3339.dateFromString(self)
}
}
class DependencyService: DependencyServiceProtocol {
private var dateFormat: DateFormatProtocol?
func setDateFormat(dateFormat: DateFormatProtocol) {
self.dateFormat = dateFormat
}
func getDateFormat() -> DateFormatProtocol {
if let dateFormatObject = dateFormat {
return dateFormatObject
} else {
let dateFormatObject = DateFormat()
dateFormat = dateFormatObject
return dateFormatObject
}
}
}