Convert rfc3339DateFormatter method to Swift

Author: mokagio

WordPressKit/NSDate+RFC3339.swift

@@ -2,8 +2,25 @@ import Foundation
 
 extension NSDate {
 
+    // TODO: Make `static let` after conversion since it's not used outside WordPressKit
+    @objc
+    static func rfc3339DateFormatter() -> DateFormatter {
+        DateFormatter.rfc3339Formatter
+    }
+
     @objc(WordPressComJSONString)
     public func wordPressComJSONString() -> String {
         NSDate.rfc3339DateFormatter().string(from: self as Date)
     }
 }
+
+extension DateFormatter {
+
+    static let rfc3339Formatter: DateFormatter = {
+        let formatter = DateFormatter()
+        formatter.dateFormat = "yyyy'-'MM'-'dd'T'HH':'mm':'ssZ"
+        formatter.timeZone = NSTimeZone(forSecondsFromGMT: 0) as TimeZone
+        formatter.locale = NSLocale(localeIdentifier: "en_US_POSIX") as Locale
+        return formatter
+    }()
+}

WordPressKit/NSDate+WordPressJSON.h

@@ -2,8 +2,6 @@
 
 @interface NSDate (WordPressJSON)
 
-+ (NSDateFormatter *)rfc3339DateFormatter;
-
 /**
  Parses a date string
 

WordPressKit/NSDate+WordPressJSON.m

@@ -2,6 +2,7 @@
 
 @implementation NSDate (WordPressJSON)
 
+// FIXME: This is here only for the benefit of dateWithWordPressComJSONString. Remove together with that.
 + (NSDateFormatter *)rfc3339DateFormatter {
     static NSDateFormatter *rfc3339DateFormatter;
     if (rfc3339DateFormatter == nil) {