Question

Is there any way I can easily check if a string conforms to the SortableDateTimePattern (“s”), or do I need to write a regular expression?

I’ve got a form where users can input a copyright date (as a string), and these are the allowed formats:

Year: YYYY (eg 1997)

Year and month: YYYY-MM (eg 1997-07)

Complete date: YYYY-MM-DD (eg 1997-07-16)

Complete date plus hours and minutes: YYYY-MM-DDThh:mmTZD (eg 1997-07-16T19:20+01:00)

Complete date plus hours, minutes and seconds: YYYY-MM-DDThh:mm:ssTZD (eg 1997-07-16T19:20:30+01:00)

Complete date plus hours, minutes, seconds and a decimal fraction of a second
YYYY-MM-DDThh:mm:ss.sTZD (eg 1997-07-16T19:20:30.45+01:00)

I don’t have much experience of writing regular expressions so if there’s an easier way of doing it I’d be very grateful!

Answer 1

Not thoroughly tested and hence not foolproof, but the following seems to work:

var regex:RegExp = /(?<=\s|^)\d{4}(-\d{2}(-\d{2}(T\d{2}:\d{2}(:\d{2}(\.\d{2})?)?\+\d{2}:\d{2})?)?)?(?=\s|$)/g;
var test:String = "23 1997 1998-07 1995-07s 1937-04-16 " + 
                  "1970-0716 1993-07-16T19:20+01:01 1979-07-16T19:20+0100 " + 
                  "2997-07-16T19:20:30+01:08 3997-07-16T19:20:30.45+01:00";
var result:Object
while(result = regex.exec(test))
    trace(result[0]);

Traced output:

1997
1998-07
1937-04-16
1993-07-16T19:20+01:01
2997-07-16T19:20:30+01:08
3997-07-16T19:20:30.45+01:00

I am using ActionScript here, but the regex should work in most flavors. When implementing it in your language, note that the first and last / are delimiters and the last g stands for global.