AJAX

AJAX is an abbreviation of Asynchronous Javascript and XML. This is a technology to access the server without reloading the page. Which means pressure decrease  on the data transmitting channels. Due to this, response time is reduced and a web app interacts more like a desktop one.

Despite the fact that the name of the technology contains the letter X (from the word XML), it is not necessary to use XML. By AJAX, we mean any communication with the server without reloading the page, organized using JavaScript.

AJAX Advantages

• Ability to create a convenient web-interface
• Active user interaction
• Partial page reload, instead of full
• The convenience of use

AJAX uses two methods of working with a web page: changing it without reloading it, and dynamically accessing the server.

What can we do with AJAX?

Interface elements

First of all, AJAX is useful for forms and buttons associated with elementary actions: add to cart, subscribe, fulfil some data in the contact form, etc. Such actions on the sites are carried out without reloading the page.

Live Search

Live search is a classic AJAX use case, adopted by modern search engines. A user starts typing a search phrase, and JavaScript offers possible options, getting a list of the most likely additions from the server.

How the System Works

AJAX technology includes the following steps:

1. A user accesses AJAX; most often this happens by pressing a button, requesting to learn more detailed information.
2. The service forwards the request to the server along with the associated data. For example, you may need to download some file or specific information from the database.
3. After receiving the response from the database, the server sends it to the browser.
4. JavaScript receives the response, decrypts and shows it to the user.

An XMLHttpRequest object is created for data exchange; it performs an intermediary function between the server and the browser. There are two types of requests - GET and POST. GET refers to a document on the server, the web resource’s URL is provided as an argument. You can use the JavaScript Escape feature to ensure query continuity. POST is used for large amounts of data and provide better security level. With POST the user’s data is transferred in the cryptographed way, with GET request all information, including the personal name and passwords, is transferred openly, directly in the body of the request code.