如何生成日期时间标记,使用ISO 8601和RFC 3339格式标准?
我们的目标是一个字符串,它看起来像这样:
"2015-01-01T00:00:00.000Z"
格式:
最好的情况:
我搜索StackOverflow上,谷歌,苹果等,还没有找到一个斯威夫特答案。
似乎最有前途的类NSDate
,NSDateFormatter
,NSTimeZone
。
相关Q&A:How do I get ISO 8601 date in iOS?
下面是我想出迄今最好的:
var now = NSDate()
var formatter = NSDateFormatter()
formatter.dateFormat = "yyyy-MM-dd'T'HH:mm:ss.SSS'Z'"
formatter.timeZone = NSTimeZone(forSecondsFromGMT: 0)
println(formatter.stringFromDate(now))
斯威夫特4•11.2.1的iOS或更高版本
extension ISO8601DateFormatter {
convenience init(_ formatOptions: Options, timeZone: TimeZone = TimeZone(secondsFromGMT: 0)!) {
self.init()
self.formatOptions = formatOptions
self.timeZone = timeZone
}
}
extension Formatter {
static let iso8601 = ISO8601DateFormatter([.withInternetDateTime, .withFractionalSeconds])
}
extension Date {
var iso8601: String {
return Formatter.iso8601.string(from: self)
}
}
extension String {
var iso8601: Date? {
return Formatter.iso8601.date(from: self)
}
}
用法:
Date().description(with: .current) // Tuesday, February 5, 2019 at 10:35:01 PM Brasilia Summer Time"
let dateString = Date().iso8601 // "2019-02-06T00:35:01.746Z"
if let date = dateString.iso8601 {
date.description(with: .current) // "Tuesday, February 5, 2019 at 10:35:01 PM Brasilia Summer Time"
print(date.iso8601) // "2019-02-06T00:35:01.746Z\n"
}
iOS版9•斯威夫特3或更高版本
extension Formatter {
static let iso8601: DateFormatter = {
let formatter = DateFormatter()
formatter.calendar = Calendar(identifier: .iso8601)
formatter.locale = Locale(identifier: "en_US_POSIX")
formatter.timeZone = TimeZone(secondsFromGMT: 0)
formatter.dateFormat = "yyyy-MM-dd'T'HH:mm:ss.SSSXXXXX"
return formatter
}()
}
可编码协议
如果您需要进行编码和解码此格式可编码协议工作时,你可以创建自己的自定义日期编码/解码策略:
extension JSONDecoder.DateDecodingStrategy {
static let iso8601withFractionalSeconds = custom {
let container = try $0.singleValueContainer()
let string = try container.decode(String.self)
guard let date = Formatter.iso8601.date(from: string) else {
throw DecodingError.dataCorruptedError(in: container,
debugDescription: "Invalid date: " + string)
}
return date
}
}
和编码策略
extension JSONEncoder.DateEncodingStrategy {
static let iso8601withFractionalSeconds = custom {
var container = $1.singleValueContainer()
try container.encode(Formatter.iso8601.string(from: $0))
}
}
游乐场测试
let dates = [Date()] // ["Feb 8, 2019 at 9:48 PM"]
编码
let encoder = JSONEncoder()
encoder.dateEncodingStrategy = .iso8601withFractionalSeconds
let data = try! encoder.encode(dates)
print(String(data: data, encoding: .utf8)!)
解码
let decoder = JSONDecoder()
decoder.dateDecodingStrategy = .iso8601withFractionalSeconds
let decodedDates = try! decoder.decode([Date].self, from: data) // ["Feb 8, 2019 at 9:48 PM"]
如果没有一些手工串口罩或TimeFormatters
import Foundation
struct DateISO: Codable {
var date: Date
}
extension Date{
var isoString: String {
let encoder = JSONEncoder()
encoder.dateEncodingStrategy = .iso8601
guard let data = try? encoder.encode(DateISO(date: self)),
let json = try? JSONSerialization.jsonObject(with: data, options: .allowFragments) as? [String: String]
else { return "" }
return json?.first?.value ?? ""
}
}
let dateString = Date().isoString
记住场景设置成在en_US_POSIX
描述Technical Q&A1480。在斯威夫特3:
let date = Date()
let formatter = DateFormatter()
formatter.dateFormat = "yyyy-MM-dd'T'HH:mm:ss.SSSZZZZZ"
formatter.timeZone = TimeZone(secondsFromGMT: 0)
formatter.locale = Locale(identifier: "en_US_POSIX")
print(formatter.string(from: date))
问题是,如果你是其中使用非公历的设备上,今年不会,除非你指定locale
还有timeZone
和dateFormat
串符合RFC3339 / ISO8601。
或者你可以使用ISO8601DateFormatter
让你出设置locale
和timeZone
自己的杂草:
let date = Date()
let formatter = ISO8601DateFormatter()
formatter.formatOptions.insert(.withFractionalSeconds) // this is only available effective iOS 11 and macOS 10.13
print(formatter.string(from: date))
对于斯威夫特2再现,看到previous revision of this answer。
如果你想使用ISO8601DateFormatter()
从一个Rails 4+ JSON饲料的日期(而不必当然米利斯),您需要设置格式的几个选项,它的权利,否则的date(from: string)
函数将返回正常工作零。下面是我使用的是什么:
extension Date {
init(dateString:String) {
self = Date.iso8601Formatter.date(from: dateString)!
}
static let iso8601Formatter: ISO8601DateFormatter = {
let formatter = ISO8601DateFormatter()
formatter.formatOptions = [.withFullDate,
.withTime,
.withDashSeparatorInDate,
.withColonSeparatorInTime]
return formatter
}()
}
下面是使用在操场截图经文不是选择的结果:
为了进一步恭维安德烈斯托雷斯马罗金狮子座Dabus,我有保留小数秒的版本。我找不到它的任何地方记录,但苹果截断秒的小数部分对输入和输出(即使使用SSSSSSS,违背Unicode tr35-31指定)微秒(精度3位)。
我要强调的是,这可能是没有必要的大多数使用情况。日期在线通常不需要精确到毫秒,而当他们这样做,它往往是更好地使用不同的数据格式。但有时必须用一种特殊的方式预先存在的系统进行互操作。
Xcode的8/9和斯威夫特3.0-3.2
extension Date {
struct Formatter {
static let iso8601: DateFormatter = {
let formatter = DateFormatter()
formatter.calendar = Calendar(identifier: .iso8601)
formatter.locale = Locale(identifier: "en_US_POSIX")
formatter.timeZone = TimeZone(identifier: "UTC")
formatter.dateFormat = "yyyy-MM-dd'T'HH:mm:ss.SSSSSSXXXXX"
return formatter
}()
}
var iso8601: String {
// create base Date format
var formatted = DateFormatter.iso8601.string(from: self)
// Apple returns millisecond precision. find the range of the decimal portion
if let fractionStart = formatted.range(of: "."),
let fractionEnd = formatted.index(fractionStart.lowerBound, offsetBy: 7, limitedBy: formatted.endIndex) {
let fractionRange = fractionStart.lowerBound..<fractionEnd
// replace the decimal range with our own 6 digit fraction output
let microseconds = self.timeIntervalSince1970 - floor(self.timeIntervalSince1970)
var microsecondsStr = String(format: "%.06f", microseconds)
microsecondsStr.remove(at: microsecondsStr.startIndex)
formatted.replaceSubrange(fractionRange, with: microsecondsStr)
}
return formatted
}
}
extension String {
var dateFromISO8601: Date? {
guard let parsedDate = Date.Formatter.iso8601.date(from: self) else {
return nil
}
var preliminaryDate = Date(timeIntervalSinceReferenceDate: floor(parsedDate.timeIntervalSinceReferenceDate))
if let fractionStart = self.range(of: "."),
let fractionEnd = self.index(fractionStart.lowerBound, offsetBy: 7, limitedBy: self.endIndex) {
let fractionRange = fractionStart.lowerBound..<fractionEnd
let fractionStr = self.substring(with: fractionRange)
if var fraction = Double(fractionStr) {
fraction = Double(floor(1000000*fraction)/1000000)
preliminaryDate.addTimeInterval(fraction)
}
}
return preliminaryDate
}
}
在我来说,我必须将DynamoDB转换 - LASTUPDATED柱(UNIX时间戳),正常时间。
LASTUPDATED的初始值为:1460650607601 - 通过转换至2016年4月14日16时16分47秒0000:
if let lastUpdated : String = userObject.lastUpdated {
let epocTime = NSTimeInterval(lastUpdated)! / 1000 // convert it from milliseconds dividing it by 1000
let unixTimestamp = NSDate(timeIntervalSince1970: epocTime) //convert unix timestamp to Date
let dateFormatter = NSDateFormatter()
dateFormatter.timeZone = NSTimeZone()
dateFormatter.locale = NSLocale.currentLocale() // NSLocale(localeIdentifier: "en_US_POSIX")
dateFormatter.dateFormat = "yyyy-MM-dd'T'HH:mm:ssZZZZZ"
dateFormatter.dateFromString(String(unixTimestamp))
let updatedTimeStamp = unixTimestamp
print(updatedTimeStamp)
}
在未来的格式可能需要改变这可能是具有date.dateFromISO8601在应用程序调用随处可见小脑袋疼。使用类和协议包的实施,改变一个地方的日期时间格式的通话将更加简单。使用RFC3339如果可能的话,它的更完整的表示。 DateFormatProtocol和日期格式是伟大的依赖注入。
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
}
}
}
有一个新的ISO8601DateFormatter
类,它可以让你创建只有一行的字符串。为了向下兼容我使用了旧的C语言库。我希望这是有用的人。
雨燕3.0
extension Date {
var iso8601: String {
if #available(OSX 10.12, iOS 10.0, watchOS 3.0, tvOS 10.0, *) {
return ISO8601DateFormatter.string(from: self, timeZone: TimeZone.current, formatOptions: .withInternetDateTime)
} else {
var buffer = [CChar](repeating: 0, count: 25)
var time = time_t(self.timeIntervalSince1970)
strftime_l(&buffer, buffer.count, "%FT%T%z", localtime(&time), nil)
return String(cString: buffer)
}
}
}
使用ISO8601DateFormatter
上iOS10或更高版本。
使用DateFormatter
上iOS9或以上。
protocol DateFormatterProtocol {
func string(from date: Date) -> String
func date(from string: String) -> Date?
}
extension DateFormatter: DateFormatterProtocol {}
@available(iOS 10.0, *)
extension ISO8601DateFormatter: DateFormatterProtocol {}
struct DateFormatterShared {
static let iso8601: DateFormatterProtocol = {
if #available(iOS 10, *) {
return ISO8601DateFormatter()
} else {
// iOS 9
let formatter = DateFormatter()
formatter.calendar = Calendar(identifier: .iso8601)
formatter.locale = Locale(identifier: "en_US_POSIX")
formatter.timeZone = TimeZone(secondsFromGMT: 0)
formatter.dateFormat = "yyyy-MM-dd'T'HH:mm:ss.SSSXXXXX"
return formatter
}
}()
}
为了配合利奥Dabus的版本,我添加了书面斯威夫特和Objective-C,还增加了可选的毫秒支持项目的支持,可能不是最好的,但你明白了吧:
xcode的8和夫特3
extension Date {
struct Formatter {
static let iso8601: DateFormatter = {
let formatter = DateFormatter()
formatter.calendar = Calendar(identifier: .iso8601)
formatter.locale = Locale(identifier: "en_US_POSIX")
formatter.timeZone = TimeZone(secondsFromGMT: 0)
formatter.dateFormat = "yyyy-MM-dd'T'HH:mm:ss.SSSXXXXX"
return formatter
}()
}
var iso8601: String {
return Formatter.iso8601.string(from: self)
}
}
extension String {
var dateFromISO8601: Date? {
var data = self
if self.range(of: ".") == nil {
// Case where the string doesn't contain the optional milliseconds
data = data.replacingOccurrences(of: "Z", with: ".000000Z")
}
return Date.Formatter.iso8601.date(from: data)
}
}
extension NSString {
var dateFromISO8601: Date? {
return (self as String).dateFromISO8601
}
}