wcf.swift

import Foundation

extension NSDate {
    convenience init?(WCFDateString dateString: String) {
        // First remove nonsense from dateString: /Date(_)/
        let dateStringSane = dateString.stringByTrimmingCharactersInSet(NSCharacterSet.decimalDigitCharacterSet().invertedSet)
        
        // Make sure dateStringSane is at least 3 characters
        guard dateStringSane.characters.count >= 3 else { return nil }
        
        // Trim ms from the string
        let dateStringTrimmed = dateStringSane.substringToIndex(dateStringSane.endIndex.advancedBy(-3))
        
        // Convert to Double
        guard let timeIntervalSince1970 = Double(dateStringTrimmed) else { return nil }
        
        self.init(timeIntervalSince1970: timeIntervalSince1970)
    }
}

NSDate(WCFDateString: "/Date(1450093658000)/") // "Dec 14, 2015, 12:47 PM"
NSDate(WCFDateString: "/Date(1450093658)/") // "Jan 17, 1970, 7:48 PM"
NSDate(WCFDateString: "/Date(1455)/") // "Jan 1, 1970, 1:00 AM"
NSDate(WCFDateString: "/Date(145)/") // nil
NSDate(WCFDateString: "/Date(14)/") // nil
NSDate(WCFDateString: "/Date(1)/") // nil