JavaScript and the DOM
Browsers render web pages by placing objects onscreen. Scripts let you grab hold of those objects to make them do special things. You can grab hold of the browser's status bar, for example, and write a message into it. You can make text on your web pages display active content, such as the current date and time. You can create rollover effects that highlight a graphic, make sounds, and pop out explanatory messages when the user moves the mouse over an object onscreen. When the user clicks a button to submit something typed into a text field, you can grab hold of the text field and validate what the user entered into it. You can also write scripts that use cookies to remember things as the user navigates from screen to screen. In this session, you will learn how to do these things in the context of the Document Object Model, which is the official definition of the objects and methods you can manipulate on a Web page.
Forms and Cookies
Dreamweaver has an application toolbar that you can use to write scripts that process forms. You will learn how to write an ASP script to receive and process data posted by a form. Then you learn to use cookies to maintain state as the user moves from page to page. As a final touch, you learn how to read the values of the cookies and make decisions based on what the user has done at your web site.
Document Object Model
The Document Object Model (DOM) is the official W3C structural definition of the objects, methods, and properties that comprise documents on the World Wide Web. By learning how to manipulate objects in the DOM, you can create some dynamic effects without needing to do any programming.
JavaScript Special Effects
You can create special effects by altering the color, size, position, and content of text and graphics depending on where the user mouses onscreen. Then you will learn how to build more intelligence into forms by having the contents of menus change depending on what the user chooses elsewhere onscreen. To conserve bandwidth, you will learn how to handle in the browser tasks that formerly required round trips to the server. Along the way, you will deepen your experience in the DOM and begin to dream of new ways to use it.
Button Rollovers
You can use JavaScript to create interesting button rollover effects. This lesson shows you how.
JavaScript
Students who are using JavaScript in their projects may find the following links useful:
New Media
New Media's product reviews of Web-based development tools provide insight into some of the latest trends and techniques.
ZDNet.com
At the Web site ZDNet.com you will find lots of cool tools that you can download and try out. Type your keywords into the search field to look for tools related to your content area.
