| There are some fast food outlets that start cooking | | | | and send you back a result (an example is attempting |
| food only after you walk up to the counter and | | | | to fetch images from certain online photo sharing |
| order it. Make no mistake, these are the inefficient | | | | sites).But suppose your desktop had a program in it |
| outlets. You end up waiting half an hour for your | | | | which anticipated what your next request could be, |
| meal to appear and vow never to go the restaurant | | | | got that information ahead of time from the server, |
| again because of the time it made you waste.Switch | | | | and kept it ready for your browser. When you did |
| to a well-organized fast-food outlet. Popular menu | | | | make the request, the information you wanted would |
| items are already waiting for you in the brightly lit | | | | be readily available in your desktop. You would not |
| 'keep warm' showcase. You walk up to the counter, | | | | have to wait for it to be fetched from the server; |
| order a burger with fries, the salesperson goes to | | | | the program gives it to your browser and it is |
| the showcase, takes out a warm, packaged burger, | | | | displayed immediately.Now think of the 'keep warm' |
| takes out fries and gives them all to you in a | | | | showcase strategy in the fast food restaurant. You |
| jiffy.AJAX is a strategy for giving you web pages in | | | | see the similarity in concepts?So here's the thing: the |
| a jiffy. I can't but help thinking that Jesse James | | | | program in your desktop that anticipates your next |
| Garrett, credited with being the brain behind AJAX, | | | | move and 'pre-fetches' data from the server is called |
| spent a lot of time at the best fast food outlets. | | | | an 'AJAX Engine'. It is written in the JavaScript |
| Why? Because the AJAX strategy is uncannily similar | | | | programming language.When it pre-fetches data from |
| to that used in a quality fast food establishment.Let's | | | | the server, it uses a programming language called |
| think for a moment about how your browser | | | | XML.The pre-fetching does not occur as a result of |
| (Internet Explorer, Firefox, whatever) fetches a web | | | | your request for a page. It happens at other times, |
| page for you. You type the URL for the page into | | | | perhaps while you are sitting back and viewing the |
| your browser. Your browser sends a request to a | | | | last page that was sent. The pre-fetching is thus not |
| computer on the internet (the 'server' at that URL) | | | | synchronized with your requests for pages. This is |
| to send that page back. The server pulls the page | | | | known technically as asynchronous pre-fetching.Hence |
| out from its store of pages and sends it to your | | | | the name Asynchronous JavaScript And XML, AJAX |
| browser, which displays the page on your | | | | for short. And guess what, Google Groups, Google |
| screen.Usually you do not have to wait more than 15 | | | | Suggest, and Google Maps are all implemented with |
| seconds for the page to reach your browser and be | | | | AJAX.It is likely that AJAX is going to show up more |
| displayed on your screen.But sometimes it can take a | | | | frequently in the design of interactive websites in the |
| whole half minute (which is the same as 'forever' in | | | | coming years. Now you do not have to wonder what |
| Internet terms) to see your page. Usually this occurs | | | | it is!Lucky Balaraman is a graduate engineer and one |
| in a situation where you have entered some data in a | | | | of the founders of The Magnum Group, a leading |
| web page, sent it down the Internet to a server, | | | | web design and CAD service provider based at |
| and are expecting the server to process your data | | | | Chennai, India. |