What is Ajax?

Ajax

  • is not a programming language.
  • is an approach to web interaction. This approach involves transmitting only a small amount of information to and from the server in order to give the user the most responsive experience possible, [1].
  • is an approach for developing dynamic Web sites, [2].
  • is not an acronym but in literature it can be in found also as AJAX, meaning Asynchronous JavaScript And XML.
  • enables us to pass information between a Web browser and a Web server without refreshing the entire Web page, [2].

Ajax is a group of technologies working together:

For presentation:

  • HyperText Markup Language (HTML) – content representation language.

  • Cascading Style Sheets (CSS) – provides stylistic formatting to XHTML.

For data display and interaction:

  • Document Object Model (DOM) – necessary to change portions of an XHTML page without reloading it.

For data interchange:

  • Extensible Markup Language (XML) – protocol used to transfer data back and forth betwen client and server.

  • JavaScript Object Notation (JSON)

For asynchronous communication:

  • XMLHttpRequest Object (XHR)

Other technologies:

  • Extensible HyperText Markup Language (XHTML) – content representation language.
  • JavaScript – scripting language used to program an Ajax engine.
  • Extensible Stylesheet Language Transformation (XSLT) – transforms XML into XHTML (with CSS linked to it).
  • RSS
  • Atom.

Two different styles of Ajax, [2]:

  • Partial-page rendering
  • JSON service

Ajax Frameworks:

  • ASP.NET is Microsoft’s Ajax Framework. ASP stands for Active Server Pages.
  • Jboss RichFaces is a Framework for integrating Ajax capabilities into applications using JavaServer Faces (JSF).

Ajax example:

Google Suggest – as we type, Google Suggest requests suggestions from the server, showing us a drop-down list of search terms that we may be interested in.