JavaScript Examples Bible - UserWorks Technologies

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JavaScript Examples Bible: The Essential Companion to JavaScript Bible
It is clear, of course, that the BODY element has an important role to play. Both
the IE4+ and W3C DOMs expose the document.body property, which returns a reference
to the BODY element of the current document. The IE4+ DOM, however,
bestows even more importance to the BODY element, by forcing it to be the frame
of reference for how much a document’s content scrolls inside a window or frame.
All other DOMs put that control into the hands of the window (that is, scrolling the
window rather than the BODY element inside the window).
Examples Highlights
✦ Observe in Listing 18-1 how (backward-compatible) document object properties
for various colors (alinkColor and the like) impact the look of the page.
It may be even more important to experience the lack of dynamic control that
these properties provide in a variety of browsers.
✦ See how IE4+/Windows exposes date information about the document in
Listing 18-4.
✦ Listings 18-11 and 18-12 provide a workshop to let you test how well your target
browsers support the document.referrer property. You may need to put
them on your server for the real test. Unfortunately, IE/Windows doesn’t
always provide the desired information.
✦ If you script for W3C-DOM compatibility, be sure to grasp the
document.getElementById() and document.getElementsByName() methods
with the help of the example steps provided.
✦ The document.write() method is one of the most important ones in the
vocabulary. Listings 18-16 through 18-18 demonstrate its power.
✦ See examples for document.body.scrollLeft and
document.body.doScroll() to control document scrolling in IE, and the
onScroll event handler example (Listing 18-21) to see how to keep a page
scrolled at a fixed position.
Document Object
Properties
activeElement
document.activeElement
NN2 NN3 NN4 NN6 IE3/J1 IE3/J2 IE4 IE5 IE5.5
Compatibility ✓ ✓ ✓