What is the preferred way to get a reference to an element in a document?

[Rosinger]

Hi all,

What is the preferred in term of browser copatability to get a
reference to an element in the document in JavaScript?

I am not sure about when to use document.all or document.layers or
document.getElementByID. Are they all doing the same thing?

Cheers,

dave

 

[David Dorward]

What is the preferred in term of browser copatability to get a
reference to an element in the document in JavaScript?

I am not sure about when to use document.all or document.layers or
document.getElementByID. Are they all doing the same thing?

Similar things.

The _standard_ way is document.getElementById, but not all browsers support
that. You could use object detection though, possibly something like:

var x;
if (document.getElementById) {
x = document.getElementById('foo');
} else if (document.all) {
...
} else if (document.layers) {
...
}

(Provisio - I'm not quite awake yet, I think the structure is right, but its
quite likely there are syntax errors in there.)

 

[Lasse Reichstein Nielsen]

I am not sure about when to use document.all or document.layers or
document.getElementByID. Are they all doing the same thing?

The preferred way is "document.getElementById". It is from the W3C DOM
specification.

In IE 4 and earlier, that function is not available, so you have to use
the Microsoft proprietary collection "document.all". Apart from being
a collection (so you access it as "document.all[id]" instead of calling
it as a function), it does the same thing as "document.getElementById".

In Netscape 4 and earlier, neither of these two are available. In fact,
there is no way to access an arbitrary element of a page. You can only
access elements through the available collections. Those are
document.images (<img> elements)
document.links (<a href...> and <area href...> elements)
document.ancors (<a name...> elements)
document.forms (<form> elements)
document.applets (<applet> applets)
document.embeds (<embed> elements)
document.layers (<layer> elements and elements with CSS position:absolute)
and
document.forms[...].elements (form elements in a form)

Most of these Netscape collections are also valuid W3C DOM, however
"document.layers" is not. If you are dealing with images, links, or
forms and their elements, you might as well use the collection.

/L

 

[Vladdy]

| Hi all,
|
| What is the preferred in term of browser copatability to get a
| reference to an element in the document in JavaScript?
|
| I am not sure about when to use document.all or document.layers or
| document.getElementByID. Are they all doing the same thing?
|
| Cheers,
|
| dave

The correct way is using document.getElementById
The browsers that do not support it are better off without javascript
anyway.

Vladdy