iOS Main Formatters

class ClassicClass {
    func forFormatting() {
        //Date Formatter
        var todayDate = Date()
        let todayString = Formatters.DateFormatters.string(todayDate)
        todayDate = Formatters.DateFormatters.date(todayString)
        Formatters.DateFormatters.standardDateFormatters(todayDate)
        Formatters.DateFormatters.customDateFormatters(todayDate)

        //Person Name Components Formatters
        var myName = PersonNameComponents()
        myName.namePrefix = "Mr."
        myName.givenName = "John"
        myName.middleName = "Gordon"
        myName.familyName = "Smith"
        myName.nameSuffix = "Esq."
        myName.nickname = "Smithster"
        let myNameString = Formatters.PersonNameComponentsFormatters.string(myName) // Mr. John Gordon Smith Esq.
        myName = Formatters.PersonNameComponentsFormatters.name(myNameString) // doesn't include nickname and often middleName appends to familyName
        Formatters.PersonNameComponentsFormatters.standardNameFormatters(myName)

        //Number Formatter
        var myNumber = NSNumber(value: 003095)
        let myNumberString = Formatters.NumberFormatters.string(myNumber) // doesn't include all start "0" (3095)
        myNumber = Formatters.NumberFormatters.number(myNumberString)
        Formatters.NumberFormatters.standardNumberFormatters(myNumber)
    }
}

struct Formatters {

    struct DateFormatters{
        static let dateFormatter = DateFormatter()

        static func standardDateFormatters(_ todayDate: Date) {
            dateFormatter.dateStyle = .full
            dateFormatter.timeStyle = .full
            print(dateFormatter.string(from: todayDate)) //Thursday, August 17, 2017 at 12:04:50 PM Moscow Standard Time

            dateFormatter.dateStyle = .long
            dateFormatter.timeStyle = .long
            print(dateFormatter.string(from: todayDate)) //August 17, 2017 at 12:04:50 PM GMT+3

            dateFormatter.dateStyle = .medium
            dateFormatter.timeStyle = .medium
            print(dateFormatter.string(from: todayDate)) //Aug 17, 2017, 12:04:50 PM

            dateFormatter.dateStyle = .short
            dateFormatter.timeStyle = .short
            print(dateFormatter.string(from: todayDate)) //8/17/17, 12:04 PM

            dateFormatter.dateStyle = .none
            dateFormatter.timeStyle = .none
            print(dateFormatter.string(from: todayDate)) //Empty String
        }

        static  func customDateFormatters(_ todayDate: Date) {
            dateFormatter.setLocalizedDateFormatFromTemplate("yyyyMMddHH:mm")
            print(dateFormatter.string(from: todayDate)) //08/17/2017, 12:34

            dateFormatter.setLocalizedDateFormatFromTemplate("MMMMd")
            print(dateFormatter.string(from: todayDate)) //August 17

            dateFormatter.setLocalizedDateFormatFromTemplate("EdMMM")
            print(dateFormatter.string(from: todayDate)) //Thu, Aug 17
        }

        static func string(_ date: Date) -> String {
            dateFormatter.dateStyle = .medium
            dateFormatter.timeStyle = .medium
            return dateFormatter.string(from: date)
        }

        static func date(_ string: String) -> Date {
            guard let date = dateFormatter.date(from: string) else { return Date() }
            return date
        }
    }

    struct PersonNameComponentsFormatters {
        static let personNameComponentsFormatter = PersonNameComponentsFormatter()

        static func standardNameFormatters(_ name: PersonNameComponents) {
            personNameComponentsFormatter.style = .default
            print(personNameComponentsFormatter.string(from: name)) // John Gordon Smith

            personNameComponentsFormatter.style = .abbreviated
            print(personNameComponentsFormatter.string(from: name)) // JG

            personNameComponentsFormatter.style = .long
            print(personNameComponentsFormatter.string(from: name)) // Mr. John Gordon Smith Esq.

            personNameComponentsFormatter.style = .medium
            print(personNameComponentsFormatter.string(from: name)) // John Gordon Smith

            personNameComponentsFormatter.style = .short
            print(personNameComponentsFormatter.string(from: name)) // John
        }

        static func string(_ name: PersonNameComponents) -> String {
            personNameComponentsFormatter.style = .long
            return personNameComponentsFormatter.string(from: name)
        }

        static func name(_ string: String) -> PersonNameComponents {
            guard let name = personNameComponentsFormatter.personNameComponents(from: string) else { return PersonNameComponents() }
            return name
        }
    }

    struct NumberFormatters {
        static let numberFormatter = NumberFormatter()

        static func standardNumberFormatters(_ number: NSNumber) {
            numberFormatter.numberStyle = .currency
            print(string(number)) // $3,095.00

            numberFormatter.numberStyle = .currencyPlural
            print(string(number)) // 3,095.00 US dollars

            numberFormatter.numberStyle = .currencyISOCode
            print(string(number)) // USD3,095.00

            numberFormatter.numberStyle = .currencyAccounting
            print(string(number)) // $3,095.00

            numberFormatter.numberStyle = .decimal
            print(string(number)) // 3,095

            numberFormatter.numberStyle = .ordinal
            print(string(number)) // 3,095th

            numberFormatter.numberStyle = .percent
            print(string(number)) // 309,500%

            numberFormatter.numberStyle = .scientific
            print(string(number)) // 3.095E3

            numberFormatter.numberStyle = .spellOut
            print(string(number)) // three thousand ninety-five

            numberFormatter.numberStyle = .none
            print(string(number)) // 3095
        }

        static func string(_ number: NSNumber) -> String {
            guard let string = numberFormatter.string(from: number) else { return "" }
            return string
        }

        static func number(_ string: String) -> NSNumber {
            guard let number = numberFormatter.number(from: string) else { return NSNumber() }
            return number
        }
    }
}