How to fill document title metadata with file name via script

Took me a while to piece working code together for an Illustrator script (jsx) that can be run from the Illustrator scripts menu, wish there was better documentation.  Sharing with everyone else...

try {
	var docRef = app.activeDocument;
	var docPath = docRef.path.fsName;
	var docName = docRef.name.replace(/(.*?)(?:\.([^.]+))?$/,'$1');
	var docExtension = docRef.name.replace(/(.*?)(?:(\.[^.]+))?$/,'$2');
	docRef = setDocumentTitleMetadata(docRef, docName);

	//do other stuff

}
catch(e) {
	alert('error:' + e.message);
}

function setDocumentTitleMetadata(docRef, title) {
	// load xmp library required
	loadXMPLibrary();
	// get full document path + name
	var fullPath = docRef.path.fsName + getPathSeparator(docRef.path.fsName) + docRef.name;
	// open xmp
	var xmpFile = new XMPFile(fullPath, XMPConst.UNKNOWN, XMPConst.OPEN_FOR_UPDATE);    
	// open xmp metadata
	var xmp = xmpFile.getXMP();     
	// unset old title
	xmp.deleteProperty(XMPConst.NS_DC, "title");
	// set new title
	xmp.setLocalizedText(XMPConst.NS_DC, "title", null, "x-default", title);
	// update xmp with new metadata
	xmpFile.putXMP(xmp);
	// close xmp
	xmpFile.closeFile(XMPConst.CLOSE_UPDATE_SAFELY);    
	// unload xmp library no longer required
	unloadXMPLibrary();
	// skipping this step will overwrite your changes if you save the active document
	closeAndOpenDocument(docRef, fullPath); 
	// return the newly opened document
	return app.activeDocument;
}

function loadXMPLibrary() {  
	 if (!ExternalObject.AdobeXMPScript) {  
		try {  
			ExternalObject.AdobeXMPScript = new ExternalObject('lib:AdobeXMPScript');  
		} 
		catch (e) {  
		  alert('Unable to load the AdobeXMPScript library!');  
		  return false;  
		}  
	}  
	return true;  
}  

function unloadXMPLibrary() {  
	 if(ExternalObject.AdobeXMPScript) {  
		try {  
			ExternalObject.AdobeXMPScript.unload();  
			ExternalObject.AdobeXMPScript = undefined;  
		} catch (e) {  
		  alert('Unable to unload the AdobeXMPScript library!');  
		  return false;
		}  
	}  
	return true;
}  

function closeAndOpenDocument(docRef, fullPath) {
	app.userInteractionLevel = UserInteractionLevel.DONTDISPLAYALERTS; 
	docRef.close(SaveOptions.DONOTSAVECHANGES);
	app.open(new File(fullPath));
	app.userInteractionLevel = UserInteractionLevel.DISPLAYALERTS; 
}

function getPathSeparator(fullPath) {
	if(fullPath.indexOf("\\") > -1) {
		return "\\";
	}
	return "/";
}

The script above updates the active document's title to the file name without the extension and then closes and re-opens the active document.  If you do not close and re-open the document saving will revert the document title to whatever is currently in the box in the user interface of Illustrator.  The document title and file name will get out of sync when changing the file name outside of Illustrator. 

Enjoy.