Learn-AJAX
One of the major concerns of information technology (IT) in the present historical moment is making the Web and web applications as efficient as possible. This insures a business’ competitive edge in this era where operating systems and applications are increasingly accessed and/or stored on the Internet. Web applications that can function on a variety of platforms or in a variety of contexts have been difficult to attain. Third-party protocols like Flash or Java’s “applets” have tried to bring more dynamism and user-friendly interactivity to web applications.
Other limitations of using web applications are the frustration and workflow interruptions that come from page-loading delays. However, the technologies encompassed in Ajax (Asynchronous JavaScript and XML) try to enable web applications so they can function quickly and efficiently in a variety of contexts without this lag time.
This article will describe the major technological components of Ajax. A brief outline of these will set the stage for understanding how they work together to enact Ajax methods that make web applications so much more competent and interoperable. Finally, this article will discuss some of the major advantages in the Ajax approach.
Ajax is a form of web development. Jesse James Garret coined the term in 2005. Ajax is not an object, but rather a practice- the working together of several pre-existing technologies. The following are the component technologies that comprise Ajax. XHTML (Extensible Hypertext Markup Language) and CSS (Cascading Style Sheets style web pages and standardize formats for consistent information-sharing over the web. The DOM (Document Object Model) is accessed with a client-side scripting language, like JavaScript.
This allows for information to be presented dynamically and in a manner that allows interaction. XMLHttpRequest objects enable asynchronous data exchange with web servers. XML (Extensible Markup Language) provides the format for transmitting data between server and client. The most important detail for formatting data in Ajax is server-side scripting. Server-side scripting allows user requests to be processed by running the script directly on the server to make dynamic and interactive HTML (Hypertext Markup Language) web pages. It is used to format and present the interface between a web page and a database.
However, Ajax is not a new thing. The technologies that make it up have been around for a while and offer tested and trusted solutions.
Ajax’s primary contribution to web pages is user-experience improvement. Web pages usually require several applications to function. This can make it seem like a cumbersome operation where users have to wait for the separate applications to refresh before interacting with the complete page. Decreasing user delay, which is a direct result of Ajax techniques, could make the Internet even more popular and pervasive than it already is.
Another advantage of Ajax is a decrease in bandwidth use. Bandwidth in web hosting refers to the amount of data that can be communicated between user and server/website. In Ajax, bandwidth is used only to accomplish specific demands without requiring that the page be re-loaded (which requires bandwidth, every time a request is made. Contents are loaded on demand and HTML is produced locally from the browser. Ajax also allows programmers to separate methods and formatting for specific information delivery functions on the Web.
Programmers can use whatever languages or formats work for their specific goal. For example, raw data, usually obtained in XML from a server-side database is separated from the format or structure of the webpage, which is usually structured in XHTML. This allows for dynamic handling of DOM. CSS use allows for the separating of style elements on the page, like fonts and picture placement. Ajax also separates the functionality of web pages by combining different elements in different ways. For example, JavaScript on the client-side browser is combined with XMLHttp to enable communication between client and server browsers. Then any server-side program or scripting language allows the programmer to quickly respond to client requests in a language and format they are familiar with.
However, one of the major advantages of Ajax and, indeed, a major trend in other forms of computer programming, is that it is based on open standards. Open standards are supported by a variety of browsers and platforms, giving programmers the accessibility and flexibility to use what they need across browsers.
