What Is Ajax

by Carol Rudenberg.
Share
|
Homepage | Submit your article | Contact | TOS
More articles on ajax and javascript  

You are here: Categories » Computers and technology » AJAX and JavaScript

Ajax stands for Asynchronous Javascript And XML. Although strictly speaking Ajax itself is not a technology, it mixes well-known programming techniques in an uncommon way to enable web developers to build Internet applications with much more appealing user interfaces than those to which we have become accustomed.

When using popular desktop applications, we expect the results of our work to be made available immediately, without fuss, and without us having to wait for the whole screen to be redrawn by the program. While using a spreadsheet such as Excel, for instance, we expect the changes we make in one cell to propagate immediately through the neighboring cells while we continue to type, scroll the page, or use the mouse.

Unfortunately, this sort of interaction has seldom been available to users of web-based applications. Much more common is the experience of entering data into form fields, clicking on a button or link, and then sitting back while the page slowly reloads to exhibit the results of the request. In addition, we often find that the majority of the reloaded page consists of elements that are identical to those of the previous page and that have therefore been reloaded unnecessarily; background images, logos, and menus are frequent offenders.

Ajax promises us a solution to this problem. By working as an extra layer between the user's browser and the web server, Ajax handles server communications in the background, submitting server requests and processing the returned data. The results may then be integrated seamlessly into the page being viewed, without that page needing to be refreshed or a new one loaded.

In Ajax applications, such server requests are not necessarily synchronized with user actions such as clicking on buttons or links. A well-written Ajax application may already have asked of the server, and received, the data required by the userperhaps before the user even knew she wanted it. This is the meaning of the asynchronous part of the Ajax acronym.

The parts of an Ajax application that happen "under the hood" of the user's browser, such as sending server queries and dealing with the returned data, are written in JavaScript, and XML is an increasingly popular means of coding and transferring formatted information used by Ajax to efficiently transfer data between server and client.

Share
Leave a comment or ask a question
Total comments: 0

AJAX and JavaScript Disclaimer

  • The e-articles directory is not responsible for any and all copyright infringements by writers and authors. If you suspect the information contained by this page for any copyright infringements, please contact us to investigate the issue
Goals of AJAX - First and foremost, AJAX is about improving user experience; user experience improvements fall into two categories: making current tasks easier and making previously impossible tasks possible. (more...)
JavaScript Lives in a Web Page - All the code that you write for JavaScript goes into an HTML page. If you don't know HTML yet, you should run out and get a good book on HTML. Lynda and William Weinman's (more...)
JavaScript Literals - The raw data that make up the root of data types are called "literals." These are, in effect, literally what they represent themselves to be. Numbers, strings, and Boolean values make up the cor (more...)
JavaScript Variables - I like to think of variables as containers on a container ship. You can put all different types of content into the containers, move them to another port, empty them, and then replace the contain (more...)
JavaScript Operators - Operators can be placed into three categories-binary, unary, and ternary. Binary operators, most commonly associated with the concept of operator, take two (binary) expressions and combine them in (more...)
JavaScript Arrays - Because objects are collections of properties with each property having its own name and value, arrays are actually JavaScript objects. Each property in an array is an element, and each element (more...)
Loops in JavaScript - Loops in JavaScript are similar to loops in C++ and Java and most other languages using loop structures. In this section, you will find explanations of the different types of loops in JavaScript (more...)
Types of operators in JavaScript - Assignment Operators The key assignment operator is the equals sign (=). The left operand is a variable, an array element, or an object property, and the righ (more...)
Conditional Structures - The "thinking" structure in JavaScript is found in the different types of conditional statements in the language. Used in concert with different types of comparative operators, conditional statem (more...)
The ''with'' Statement - Like the ternary conditional operator, the with statement is a shortcut. Instead of having to list all of the properties of an object by repeating the basic object, you can state the bulk (more...)
 
free content
    Copyright © 2006 - 2012 e-articles.info.
The texts, articles and tutorials in the directory are property of their respective owners and authors.