Dynamic Web Development with Seaside

20Dynamic Content with Scriptaculous

While a simple web application requires communication with the server for each update of the display, refresh or any action, JavaScript-enabled applications can allow some part of the computation to be done in the client without requiring the server to recreate and resend the complete XHTML defining the page. This allows you, for example, to have UI updates without forcing the user to explicitly click on a link or press a button.

JavaScript running in the web browser can also communicate with the web server without the need to reload the whole page. This provides you with a lightweight way to provide updates to the contents of your application’s pages, such as stock tickers.

The use of these techniques allows you to build highly dynamic and interactive web applications that behave like desktop applications rather than traditional web pages. Google’s web mail client is a great example of how well this approach can work.

In this chapter, we give a brief description of the JavaScript frameworks Seaside supports. Then we explain how you can add JavaScript effects to your applications and show how you can take advantage of AJAX to support the communication between the client side and the server.

