Can ActionScript tell when a SWF was published? - actionscript-3

Question

I'd like to write a little class that adds a Day/Month box showing the date a SWF was published from Flash.
The company I work for regularly produces many, many SWFs and many versions of each, iterating over the course of months. A version-tracking system we've been using to communicate with our clients is a Day/Month date-box that gives the date the SWF was published. Up until now, we've been filling in the publish date by hand. If there's any way I can do this programatically with ActionScript that'd be fantastic.
Any insight? Basically, all I need is the call that gives me the publish date, or even.. anything about the circumstances under which a SWF was published that I could use to roll into some form of.. automated version identification, unique to this SWF.
So, can ActionScript tell when a SWF was published?

Answer 1

George is correct. Adobe sneaks an undocumented ProductInfo tag that contains the compilation date in to every compiled swf. The DisplayObject.loaderInfo.bytes contains the the complete uncompressed swf that loaded the Display Object.
http://livedocs.adobe.com/flash/9.0/ActionScriptLangRefV3/flash/display/DisplayObject.html#loaderInfo
So the quickest way to get the swf's compilation date without external libraries (from a Display Object):
import flash.utils.Endian;
import flash.display.LoaderInfo;
import flash.utils.ByteArray;
...
private function getCompilationDate():Date{
if(!stage) throw new Error("No stage");
var swf:ByteArray = stage.loaderInfo.bytes;
swf.endian = Endian.LITTLE_ENDIAN;
// Signature + Version + FileLength + FrameSize + FrameRate + FrameCount
swf.position = 3 + 1 + 4 + (Math.ceil(((swf[8] >> 3) * 4 - 3) / 8) + 1) + 2 + 2;
while(swf.position != swf.length){
var tagHeader:uint = swf.readUnsignedShort();
if(tagHeader >> 6 == 41){
// ProductID + Edition + MajorVersion + MinorVersion + BuildLow + BuildHigh
swf.position += 4 + 4 + 1 + 1 + 4 + 4;
var milli:Number = swf.readUnsignedInt();
var date:Date = new Date();
date.setTime(milli + swf.readUnsignedInt() * 4294967296);
return date; // Sun Oct 31 02:56:28 GMT+0100 2010
}else
swf.position += (tagHeader & 63) != 63 ? (tagHeader & 63) : swf.readUnsignedInt() + 4;
}
throw new Error("No ProductInfo tag exists");
}
The SWF Specification: http://www.adobe.com/content/dam/Adobe/en/devnet/swf/pdf/swf_file_format_spec_v10.pdf

Answer 2

Also you can read the date from the SWF bytecode with the awesome as3swf library.
Check this out.

Answer 3

I'm afraid you can't do it in Actionscript. Depending on how you build the swfs, there might be a couple of options. For instance, if you use the Flash IDE, you could use a JSFL script to publish the swf. This jsfl could replace a placeholder variable where you will store the publication date, and the publish the swf (haven't write a JSFL script in a long time but it shouldn't be too hard to get this working).
So, let's say you have a Version class:
public class Version {
public var publicationDate:Date = new Date();
}
Your script should read the file where this class lives, find that line and replace it with the current date:
Something like this:
var curDate = new Date();
var dateLine = "public var publication:Date = new Date(" + curDate.getFullYear() + "," + curDate.getMonth() + "," + curDate.getDate() +");";

Answer 4

In case you're using FlashDevelop (which is very nice lightweight, free AS3 IDE) you can do this:
public static function GetBuildDate() : String
{
return CONFIG::timeStamp;
}
It returns date in format YYYY-MM-DD
More info: http://www.flashdevelop.org/wikidocs/index.php?title=AS3_Conditional_Compilation

Answer 5

Not sure if this would work, but could you use an 'include' statement which calls in an externally generated .as file at compile time which has the (then) current date hard-coded into it? You'd need to have a script of some kind running on your server to update this file once a day to keep it current.