AJAX is getting a lot of attention with the likes of Flickr.com, backpackit.com and Google Mail already changing the landscape of what can be done with greater speed and yet retain GUI richess while working in the relatively familiar JavaScript/HTML/CSS/XML/DOM world that is DHTML. We have raised big view issues and AJAX is far from fall-off-a-log simple requiring as much as 10-20K lines of code per component for some aynchronous or online/offline operations. Here are some current readings that act as a leavening on what can and cannot be done with AJAX:
Adam Bosworth – one of the IE designers of XMLHttpRequest, adds some notes of caution
Alex Bosworth – Adams son who describes 10 shortcomings in AJAX
Thomas Baekdal – provides some very well thought out AJAX usability guidelines
Michael Mahemoff – looks at AJAX design patterns, and provides lots of links
AJAXMatters – site devoted to AJAX with list here of AJAX using sites
Jason Gitlin – provides great AJAX intro and error catching at the same time
A second caution is due. Flash, JSF, and good old Java Applets and J2ME provide solutions to real world subsets of our 7 point Presentation Layer Problems that AJAX is not yet prepared to cope with. Example 1: XMLHttpRequest may become overwhelmed scalability and functionality-wise by large scale and or complex transactions with business rules that handle well in JSP or Flash/Flex space. Example 2: Both XML and JavaScripts plain text source code used in AJAX poses serious hacking/security risks which I have yet to see developers address explicitly. Example 3: It can be done but there is little showing in AJAX yet for incorporating and interoperating with animations, video, 3D graphics, sound and containered fonts and styling (the Flash solution set). If SVG which is coming in Firefox/Mozilla (but heaven knows from IE and Opera??) gets adopted the problem is less acute but still real.
But the bottom line is that AJAX has re-energized what people expect from a browser-GUI experience (desktop or mobile); laser-focused on the issue of standards compliance within browsers (i.e. Microsofts IE7 team will be in very deeeeeeeppp doo doo if they fail to deliver an updated browser that does not meet current state HTML, CSS, DOM, XML standards or worse, spring a hunk of proprietary code on developers); and really extended thinking on just how big the local browser cache or sandlot is. In sum, AJAX is good news for developers.
(c)JBSurveyer 2005