1. COP 3813 Intro to Internet Computing
Prof. Roy Levow
Lecture 7
DHTML Intro

2. Dynamic HTML Warning! Microsoft DHTML and Netscape DHTML are different
They are not compatable
Examples run under IE but not Netscape

3. Dynamic HTML Object Model
XHTML elements can be treated as objects
Their XHTML attributes become properties of the objects
The properties can be manipulated by scripts for dynamic effect
The id attribute defines the object name
Example: reference.html

4. Collections all and children
A collection is basically an array of related objects
The ‘all’ collection consists of all XHTML elements of a document
The ‘children’ collection of an object consists of all the immediately contained elements
Examples: all.html, children.html

5. Dynamic Styles Styles can change dynamically
Example: dynamicstyle.htlm
Font attributes can change dynamically
Example: dynamicstyle2.html
Position can change dynamically
Example: dynamicposition.html

6. DHTML Events
The script tag can contain an event attribute with a script to execute as its value
The action can be limited by the ‘for’ attribute.
Example: onclick.html
On load is triggered when page loads
Example: onload.html

7. Error Handling
The onerror attribute specifies a function to execute if there is an error
Three parameters: errType, errURL, errLineNum
Passed by system
Example onerror.html

8. Mouse Events onmousemove provides event object properties include
button
clientX/clientY – position in client window
offsetX/offsetY – position in current object
screenX/screenY – screen position
cancelBubble – events bubble up from innermost object
Example: onmousemove.html

9. Rollovers onmouseover, onmouseout Event bubling
Example: onmouseoverout.html
Event bubling
Example: bubbling.html