What is AJAX?
Modern websites offer a high degree of interactivity and must be able to react dynamically to user input. When creating an e-mail account, for example, before the data is transmitted, it could be checked whether the desired e-mail address is available or whether the password meets the minimum level of security. Such and similar scenarios can only be implemented if individual components of the website can be manipulated regardless of the moment at which the website is loaded. AJAX is a procedure with which this asynchronous data transfer between server and client can be implemented.
The greatest advantage of AJAX is that websites no longer have to be completely reloaded in order to react to user input. Static content remains unchanged, while dynamic information can be added to the DOM (Document Object Model) as required. In the above example with the creation of a new e-mail account, a request must be sent to the responsible web server so that it can check whether the desired username is available.
Instead of having to lead users to a new website for each new step, only certain parts of the page with the relevant content are changed. This not only saves time but also bandwidth and offers a better user experience.
How does AJAX work?
Properties and special features of AJAX
As we have already mentioned in the above paragraph, the functionality of traditional websites and web applications can be described with the principle of “stop and go”: the visitor triggers an action on a website and waits for the responsible server to process this action and the website then updated.
With AJAX applications, server requests are started in the background without having to change an HTML document. This means that there is no longer any need to wait for a response from the responsible web server, or the server only has to send back a small data packet. The main advantage of Ajax-based web applications is that they react much faster to user actions and thus come closer to the smooth behavior of native apps and desktop applications. This has an extremely positive effect on the user experience and usability.
How can I use AJAX when developing?
The “X” in AJAX stands for “Extensible Markup Language”. This is the XML markup language. While page content is defined and designed with HTML and CSS, XML is used for asynchronous data transfer.