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The Workbench
Articles
Useful Scripts

Chapter 10: JavaScript and Cookies

Contents:

Baking Your First Cookie
Reading a Cookie
Showing Your Cookies
Using Cookies as Counters
Deleting Cookies
Handling Multiple Cookies
Displaying "New to You" Messages

Return to Chapter 10

To use this script on your own page, click in the text area below, select all, and copy to grab the script. Then, just paste into your own page — and you're done.

Displaying "New to You" Messages

See it run: Displaying "New to You" Messages

Script 10.9

The CSS used in the HTML of this page applies the next script's results to the page.

Script 10.10

This JavaScript can help you personalize your site by alerting the user to new content.

window.onload = initPage;

function initPage() {
	var now = new Date();
	var lastVisit = new Date(cookieVal("pageVisit"));
	var expireDate = new Date();
	expireDate.setMonth(expireDate.getMonth()+6);
	
	document.cookie = "pageVisit=" + now + ";expires=" + expireDate.toGMTString();
	var allGrafs = document.getElementsByTagName("p");
	
	for (var i=0; i<allGrafs.length; i++) {
		if (allGrafs[i].id.indexOf("New-") != -1) {
			newCheck(allGrafs[i],allGrafs[i].id.substring(4));
		}
	}	
	
	function newCheck(grafElement,dtString) {
		var yyyy = parseInt(dtString.substring(0,4),10);
		var mm = parseInt(dtString.substring(4,6),10);
		var dd = parseInt(dtString.substring(6,8),10);
		var lastChgd = new Date(yyyy,mm-1,dd);
			
		if (lastChgd.getTime() > lastVisit.getTime()) {
			grafElement.className = (grafElement.className == "") ? "newImg" : "newImg " + grafElement.className;
		}
	}
}

function cookieVal(cookieName) {
	var thisCookie = document.cookie.split("; ");

for (var i=0; i<thisCookie.length; i++) {
		if (cookieName == thisCookie[i].split("=")[0]) {
			return thisCookie[i].split("=")[1];
		}
	}
	return "1 January 1970";
}

Images: