JavaScript & DOM

Any web developer must have knowledge of this. In earlier days html are hand-written and site had more java-script decorators. Slowly they were disregarded, the gimmickry effects are considered to be not-so useful, and mostly distracting the user. A plain site with clean navigation flow is considered more useful. Even for data-validation, the java-script which runs at the client is considered risk. So they moved them to server, and preferred server-side validations to client-side validations. Servlets & JSP reduced the developer to directly interact with core html, and often helped to generate dynamic html, and do server-side validations with controller components

A good understanding of DOM model is very much required for any web developer. With Web2.0, an over used term, often meaning to give power to the user, by providing interactive user interface; JavaScript is playing a role again.

JavaScript is most supported client side script, by the browsers. Even though JSP’s support various scripting language under the BSF model, JS is most commonly supported by all.

Where is JavaScript now -- Version 1.5

Upcoming JavaScript 2.0

http://www.quirksmode.org/js/support.html

FireFox1.5 supports JavaScript version 5, but still IE 7 beta just supports JavaScript 1.3, with many browsers in the market, we have to be careful to choose correct version of JS, to reach wider users.

DOM2 is recent specification released, by w3c, hopefully supported by common browsers soon. Best is to stick with DOM0 or DOM level1, based on the functionality you require.