Disadvantage/Drawback of AJAX.
AJAX technology is very help full but as we know every coin has two aspect . Like other AJAX technology also have some drawbacks/disadvantage some are list below. So before developing your application with AJAX you should know about advantage and disadvantage of AJAX.
1. The page address doesn’t change while working , so you can’t bookmark
AJAX-enabled pages.
2. Search engines may not be able to index all protions of your AJAx
application site.
3. The Back button in browsers , doesn’t produce the same result as with
classic web applications, because all actions happen inside the same page.
4. Javascript can be disabled at the client side, which makes the AJAX
application non-functional, so it’s good to have another plan in your
site, whenever possible, to avoid losing visitors.
What onreadystatechange event of ajax ?
Sep 18, 2009 Ajax
0: uninitialized
Open request has not been called yet.
1:loading
Send request has not been called yet.
2:loaded
send request has been called,but the response is yet not availble.
3: interactive
The response is being downloaded ,and ther responseText property holds
partial data.
4:completed
The response has been loaded and the request is completed.
How Ajax works ?
Sep 18, 2009 Ajax
1. Javascript makes invisible call to server
2. sever replies by sending requested data
3. javascript update web page this data.
How to create XMLHttpRequest in ajax ?
Sep 18, 2009 Ajax
function creatObject() Read the rest of this entry »
{
var xmlHttp;
try
{
xmlHttp=new XMLHttpRequest();
}
catch(e)
