which DOM level to use?

[YAD]

How do you decide which DOM level you should use? I've been told level 2
is the "modern" approach, but also saw a website that said use level 0
any time you can.

Should you use higher-level code where lower-level code works? Does
lower-level code fail in modern browsers? What are the issues you have
to worry about?

--
Yet another Dan

[RobG]

YAD wrote:

How do you decide which DOM level you should use? I've been told level 2
is the "modern" approach, but also saw a website that said use level 0
any time you can.

DOM 0 is just the stuff that both Navigator and IE supported when DOM 1
was introduced. It is possible (though not yet likely) that new
browsers will start to drop support for DOM 0 since it isn't in any W3C
standard.

Should you use higher-level code where lower-level code works? Does
lower-level code fail in modern browsers? What are the issues you have
to worry about?

Use DOM 2 with feature detection and fallback. Use DOM 0 only where:

- you know there is an issue with the implementation of a
particular DOM 2 feature in a browser you need to support
(for the web that's all of them)
- DOM 0 proivdes a more widely supported alternative, and
- there is no easy test to use for fallback

For example, IE's issue with using createElement for option elements -
it's easier to just use new Option.
--
Rob

[Richard Cornford]

YAD wrote:

How do you decide which DOM level you should use?

That question is maningless.

I've been told level 2 is the "modern" approach, but also
saw a website that said use level 0 any time you can.

Generally, if any single feature of any DOM (or pre-DOM/non-DOM) can be
verified to be available and functioning correctly it can be used. Some
(but not all) of the features of what it called DOM Level 0 as so
universal that they could be assumed to be available without
verification, using those features then becomes advantageous as it
avoids the need to test for them.

Should you use higher-level code where lower-level code
works?

If you can verify that the higher level DOM features are available and
function correctly.

Does lower-level code fail in modern browsers?

No and yes.

What are the issues you have to worry about?

Designing the whole system so that there are sensible outcomes following
the verification of the unavailability of features required by scripts.

Richard.

[Richard Cornford]

Richard Cornford wrote:

YAD wrote:

>How do you decide which DOM level you should use?

That question is maningless.

<snip>

And that would make more sense if it was "meaningless".

Richard.

[YAD]

Richard Cornford wrote:

YAD wrote:

>How do you decide which DOM level you should use?

That question is maningless.
And that would make more sense if it was "meaningless".

It would make even more sense if you would explain why or how
it's meaningless. If you decide to use a DOM-2 feature in a web
page, aren't you using DOM-2? What's meaningless about that?

Also, what about DOM-1 vs. DOM-2?
I'm asking the general question about how you decide
what features to use, not just level 0 and level 2.
Do essentially all browsers support DOM-1 these days?
Is it much safer than DOM-2?

>What are the issues you have to worry about?

Designing the whole system so that there are sensible outcomes following
the verification of the unavailability of features required by scripts.

But more specifically, suppose you can write the whole page without
DOM-2 features. Is there any reason you should use DOM-2 anyway
just because it's more up-to-date? Or should it be avoided except
where lower levels don't provide the functionality you need?
How aggressive should you be about moving away from lower DOM levels?
--
Yet another Dan