What is AJAX?

AJAX = Asynchronous JavaScript and XML.

In short; AJAX is about loading data in the background and display it on the webpage, without reloading the whole page.

Examples of applications using AJAX: Gmail, Google Maps, Youtube, and Facebook tabs.

AJAX is Asynchronous JavaScript And XML.

The XmlHttpRequest is an actual object which works behind the scene.

Ajax implementation uses JavaScript functions to call methods from a webservice, webpage request in response to get response.

Response data is parsed using DOM.

Asynchronous data retrieval using XmlHttpRequest

AJAX Advantages

  • AJAX Learn:Ajax is easy to learn and understand.
  • Speed:Reduce the Server Traffic in both side request to or from. also reduce the time consuming on both side response.
  • Interaction:AJAX is much responsive, whole page(small amount) data transfer at a time.
  • XMLHttpRequest:It can be used by Web browser scripting languages, such as JavaScript to transfer XML and other text data to and from a Web server using HTTP. It is used for making requests to the non-Ajax pages.
  • Asynchronous calls:AJAX allows for the ability to make asynchronous calls to a web server. This allows the client browser to avoid waiting for all data to arrive before allowing the user to act once more.
  • Form Validation:This is the biggest advantage. Form validation should be instant and properly. AJAX gives you all of that, and more. form validation is the easiest way to get a proper validation.
  • Bandwidth Usage:No require to completely reload page you are really using less server bandwidth, and when you are in countries or places that charge for your surfing bandwidth, it really is something to think about.
  • Open Standard: Ajax is supported by almost every web browser and platform. Even now it comes in the count of most trusted brands of application platform in the world.
  • Limited processing on the server: As we know that in case of Ajax, the server is not required to process all the form elements, only the necessary data is sent to the user. So there is a limited processing on the server.
  • Bandwidth Reduction: The components of the site which are requested are loaded very fast with the help of Ajax application. Since the web page does not need to reload its complete content, the bandwidth required per request also undergoes a significant reduction.
  • Vast compatibility range: On one side Ajax is browser independent, and on the other, it’s applicable to most of the standard web servers and server-side languages, be it PHP, ASP, ASP.net, Cold Fusion, Perl or any other.
  • Reduce the traffic travels between the client and the server.
  • Response time is faster so increases performance and speed.
  • You can use JSON (JavaScript Object Notation) which is alternative to XML. JSON is key value pair and works like an array.
  • You can use Firefox browser with an add-on called as Firebug to debug all Ajax calls.
  • Ready Open source JavaScript libraries available for use – JQuery, Prototype, Scriptaculous, etc..
  • AJAX communicates over HTTP Protocol.
  • No cross browser pain
  • U can trust that good developer have spent there time and energy making library
  • U can focus more on actual problem and not on side effects
  • API’s are good. If someones tells UI developer that ajax, HTTP, JavaScrtip bla bla bla…….. OFFFF simple function is always great Ajax.call(url, callbackfunction, param). That is all we are looking for most of the times.
  • Great time saving 🙂 and u can enjoy parties no late night work

AJAX Disadvantages

  • AJAX application would be a mistake because search engines would not be able to index an AJAX application.
    2. Open Source: View source is allowed and anyone can view the code source written for AJAX.
    3. AJAX is not well or full integrated with any browser.
    4. ActiveX requests are enabled only in IE5 and IE6 in old version. now this feature is available in latest version few new browsers.
    The last disadvantage lies in the actual XMLHttpRequest object itself. Due to security constraints, you can only use to access information from the host that served the initial page. If you need to display information from another server, it’s is not possible with in the AJAX.
  • It can increase design and development time
  • More complex than building classic web application
  • Security is less in AJAX application as all files are downloaded at client side.
  • Search Engine like Google cannot index AJAX pages.
  • JavaScript disabled browsers cannot use the application.
  • Due to security constraints, you can only use it to access information from the host that served the initial page. If you need to display information from another server, it is not possible within the AJAX.
  • Its long history of battles between browser and specification that end up in real mess. We as developer understand it when we realize that we are spending more time resolving cross browser specific issues instead of solving the programming business logic/problem.
  • U will be playing on smooth surface and saving skin from headaches that are good for we as software engineers
  • If you use some profiler you will find few dozens of call made inside that function for doing the things using library which consumes few of MILLISECONDS. but this is not really a big deal considering time we saved during the development
  • You have to trust on the library regarding what they say. So i will suggest to stick to good ones only. And yes u r using one of the finest

Good luck…