Lesson 30: JavaScript and DHTML Fundamentals

Objectives Define and contrast client-side and server-side technologies used to create dynamic content for Web pages Use JavaScript dot notation to access X/HTML objects Identify common JavaScript objects, properties and methods Use JavaScript to detect browsers, redirect pages, preload pages and confirm user choices Define Dynamic HTML (DHTML) and the technologies it requires, and identify browser-specific DHTML code for use with Microsoft Internet Explorer, Netscape and Mozilla

JavaScript and Common Programming Concepts Scripting languages –Subsets of larger languages Objects –Encapsulate predetermined attributes or behaviors Properties –Represent various attributes of the object Methods –Actions an object can be made to perform

What Is JavaScript? Scripting language Object-based, not object-oriented Event-driven Strengths of JavaScript –Quick development –Easy to learn –Platform independence

JavaScript vs. Other Languages JavaScript vs. Java JavaScript vs. VBScript JavaScript vs. JScript –ECMA Script

Embedding JavaScript into X/HTML The tag Document or section Dot notation

Using JavaScript to Communicate with the User The alert() method The prompt() method –Concatenation The open() method

Using JavaScript for Browser Detection The navigator object Sniffers and redirections Image preloading

Dynamic HTML (DHTML) DHTML and the Document Object Model (DOM) DHTML limitations CSS and DHTML Scripting languages and DHTML DHTML implementation Cross-browser DHTML

Summary Define and contrast client-side and server-side technologies used to create dynamic content for Web pages Use JavaScript dot notation to access X/HTML objects Identify common JavaScript objects, properties and methods Use JavaScript to detect browsers, redirect pages, preload pages and confirm user choices Define Dynamic HTML (DHTML) and the technologies it requires, and identify browser-specific DHTML code for use with Microsoft Internet Explorer, Netscape and Mozilla