The Web Wizard

1
The Web Wizards Guide To JavaScript

• Chapter 9
• Applied Web Programming Techniques

2
Chapter Objectives

• To learn how to use a triple nested loop to
  generate an interactive table of Web-safe colors
• To discover how to combine JavaScript with
  client-side image mapping to enhance the user
  interface of your Web pages
• To find out how to detect the visitors browser
  and platform
• To understand how to change the text displayed in
  the visitors status bar to provide your own
  content
• To learn how to create scrolling text in a text
  field
• To get a glimpse of how Dynamic HTML and
  Cascading Style Sheets can boost the power of
  your JavaScript programming

3
Generating Content with Nested Looping

• You can use a short group of nested loops to
  create lengthy and complex tables that include
  background colors and JavaScript code.
• When you include quotes within quotes within
  quotes, you may need to escape the most deeply
  nested quote using the backslash character.

4
JavaScript and Client-Side Image Mapping

• By using client-side image maps with JavaScript,
  you can create novel and compelling user
  interfaces that involve substantial
  interactivity.
• You can use pseudo-URLs and onclick handlers to
  execute JavaScript code when links and map areas
  are clicked.

5
Browser Detection

• Browser detection is often necessary to deliver
  different content for different browsers and
  platforms.
• Browser detection scripts (sniffers) are ideal
  candidates for placement in external code
  libraries such as your mylibrary.js file.

6
Text in the Status Bar

• You can control the text that is displayed in the
  status bar of visitors computers.
• To avoid interfering with status messages coming
  from the browser, be sure to place only temporary
  information in the status bar. An example is a
  short message that appears when visitors move the
  mouse over a link.

7
Scrolling Text in a Field

• Scrolling text in a form field is an economical,
  low-bandwidth way to attract the attention of
  visitors to important announcements on your page.

8
Whats Next?

• Your new skills in JavaScript programming will
  assist you in creating Dynamic HTML and using
  authoring environments such as Flash and
  Director.
• Dynamic HTML is the combination of JavaScript,
  HTML 4, and Cascading Style Sheets.
• Flash and Director are two of many products that
  use JavaScript or JavaScript-like languages to
  create interactivity.