Formatters.txt

public struct Formatters {
    
    public enum DateFormatterType {
        case ISO8601
        case medium
    }
    
    static func string(from date: Date, for type: DateFormatterType) -> String {
        return formatter(for: type).string(from: date)
    }
    
    static func date(from string: String, for type: DateFormatterType) -> Date? {
        return formatter(for: type).date(from: string)
    }
    
    private static let iso8601: DateFormatter = {
        let dateFormatter = DateFormatter()
        dateFormatter.locale = Locale(identifier: "en_US_POSIX")
        dateFormatter.dateFormat = "yyyy-MM-dd'T'HH:mm:ssZZZZZ"
        
        return dateFormatter
    }()
    
    private static let medium: DateFormatter = {
        let dateFormatter = DateFormatter()
        dateFormatter.dateStyle = .medium
        dateFormatter.timeStyle = .medium
        
        return dateFormatter
    }()
    
    private static func formatter(for type: DateFormatterType) -> DateFormatter {
        switch type {
        case .ISO8601:
            return iso8601
        case .medium:
            return medium
        }
    }
}

extension DateFormatter {
    
    static var fmt = Formatters.self
}