What is DHTML?

DHTML = Dynamic HTML

Ability to change style (visibility, appearance, position) and content of document in response to browser events.

DHTML components

1. The document

• The document contents, carefully marked up in valid HTML!

2. The style sheet

• The display rules for the document contents
• We'll use cascading style sheets.

3. The scripting language

• The tool for changing document contents and display styles.
• We'll use javascript.

• Components:
  • Usual scripting language logic and flow-control stuff:
    What to do.
  • Document object model (DOM): the rules for identifying a chunk of the document contents.
    Where to do it
  • Event handlers: methods for detecting and acting on browser events.
    When to do it

The complication

... of course!

• DHTML concepts have evolved quickly.
• DOMs used in common browsers are very different
• We'll spend some time looking how to write DHTML that works across browsers.