robodesign at gmail.com
Sat Feb 4 03:06:25 PST 2006
On Sat, 04 Feb 2006 03:49:23 +0200, Brad Fults <bfults at gmail.com> wrote:
> On 2/3/06, Jim Ley <jim.ley at gmail.com> wrote:
> I can't believe that you're so insistent upon this extremely narrow
> set of use cases and that there aren't any other popular use cases for
> If there are no use cases for this function then what are the use
> cases for getElementById()? I suppose this should be
> addEventToElementById()? How about getElementsByTagName()? That one
> too, eh?
> The point of getElementsByClassName() is superior control over the
> DOM. Where getElementById() falls short by only returning one element
> and getElementsByTagName() falls short by only returning one,
> document-mandated type of element, getElementsByClassName() gives the
> author the control to collect arbitrary sets of elements which all
> share the same class or set of classes.
> Completely irrelevant. See getElementById() or getElementsByTagName().
> The requirement for a loaded document is to be expected when one
> wishes to manipulate the constructed DOM from that document.
Very good point. There are many use-cases for getElementsByClassNames().
This is not a useless function, it's a very useful one.
Lets take the IMDB site. Comments are marked as being positive or
negative, so users can pick which type of comments they want to see. Each
comment *could* (it is not currently AFAIK) styled accordingly (like
change the background-color for negative comments, or whatever). It is
fair to assume that the negative and positive comments will have their own
class name. With getElementsByClassNames() you can have a UserJS that
manipulates those comments (for example, it could parse them all and save
a local db of negative comments :) ).
finds all emoticons from comments (yes, each emoticon has
class="emoticon"). I could do "cool" things with 'em using
getElementsByClassNames(). If I currently want to manipulate all the
emoticons from JS I have to use getElementsByTagName('img') then check for
.className="emoticon" which is slow and not very efficient.
Now ... we could go on and provide many more imaginary use-cases ... or we
can go on and discuss something else :).
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