AJAX

JaxFusion April 2006

David Fekke

Who am I?

David Fekke Lead Software Engineer

Data Inteligence Group http://www.fekke.com/blog/ davidfekke@gmail.com

Ajax?

What is Ajax?

Just kidding!

Asynchronous JavaScript and XML Makes use XMLHttpRequest object in

concert with the dynamic html and XML

Whats all the hype about

Fully buzzword compliant Web 2.0 Build truly dynamic web applications

Some examples

Google Maps Gmail Local.live.com

History

Nothing new here Remote scripting 1998 Major differences between IE4 and

Netscape 4, IFRAME vs LAYER Term coined by Adaptive Path

XMLHttp Request Object

Syntax different depending on browser Mozilla, Safari, Opera

new XMLHttpRequest() Internet Explorer

new ActiveXObject("Microsoft.XMLHTTP")

XMLHttp methods and properties

XMLHTTPObj.open(“get”,url,true); .setRequestHeader(“name”,”value”); .send(); .responseText; .responseXML;

XML methods & properties

getElementsByTagName()[]; childNode[1].nodeValue; firstChild.nodeValue; UDF getElementTextNS()

DHTML methods & properties

getElementById(); innerHTML; createElement(); appendChild(); createTextNode();

Transport methods

SOAP REST

ColdFusion Ajax frameworks

Cfajax AjaxCFC JSMX IBM WSAjax

Pros

Pull back small pieces of data without having to reload the whole page.

Can save bandwidth More Interactive

Cons

Back button does not work as expected

Security issues Network latency Compatibility, older browsers,

JavaScript inactivated Accessibility

Compatible Browsers

IE5+ Gecko based browsers, Mozilla,

Firefox, Netscape 7.1+ . . . KHTML, Konqueror, Safari 1.2+ Opera 8+

Non compatible browsers

Opera 7 and lower Lynx, text based Visually impaired browsers

Resources

http://adaptivepath.com http://www.indiankey.com/cfajax/ http://developer.apple.com/internet/we

bcontent/xmlhttpreq.html http://www-128.ibm.com/

developerworks/webservices/library/ws-wsajax/