Adding Ajax

In practical examples, it is shown how to add ajax effects into already existing web applications and make sites more interactive, without reworking them entirely. Briefly given the basis of AJAX technologies, the principles of operation with XmlHttpRequest objects and creating requests to the web server. The main libraries of AJAX are described, including Prototype, Script.aculo.us, Rico and Mochikit. Interactive AJAX effects are considered: the use of events and event handlers. ACCORDION type elements, pages with tabs, pop-ups, etc. are described. Data update methods are given, including adding new data, delete and update, and all this is within one page. The reasons for the occurrence of the effects of type "breakdowns" of the return button or loss of visits history and ways to eliminate most such problems are explained. Some complex CSS effects are disclosed, including the use of SVG and CANVAS objects. Presentation of writing Mashup applications, affected issues of scaling, distribution of resources and security of web applications