Getting the value of a selected option

[skunkbad]

I've got a standard select box with options, and the select box has an
id of "theme_choice"

I've found the following script online, but it isn't popping up an
alert when a selection is made:


$$('#theme_choice').each(function(elem){
if (elem.selected) alert(elem.text + ' ' + elem.value);
});


Prototype is called just before this in the head area of the page. I'm
using the latest version RC3.

This is for a theme changer script on my website. I have a current
theme changer script, but I'm trying to play around with prototype.

I don't know if it is spam to put a link to my website or reference
it, so I won't, but the select box with options is really just a
standard form element. Nothing special.

Thanks for your help.

[T.J. Crowder]

Hi,

> I've found the following script online, but it isn't popping up an
> alert when a selection is made:

You're not asking it to. :-) You're asking it to pop up an alert if
something is selected at the moment you're calling that code; you
haven't hooked up an event handler. To make it happen when something
is selected, you'll need to observe the 'change' event (probably).
You probably also want $('theme_choice') rather than $$
('#theme_choice')[1][2]. More here[3][4].

[1] http://prototypejs.org/api/utility/dollar
[2] http://prototypejs.org/api/utility/dollar-dollar
[3] http://prototypejs.org/api/element/observe
[4] http://prototypejs.org/api/event/observe

HTH,
--
T.J. Crowder
tj / crowder software / com
Independent Software Engineer, consulting services available

[ColinFine]

Incidentally, (not answering your question, which TJ has done)

> $$('#theme_choice').each(function(elem){
>                                 if (elem.selected) alert(elem.text + ' ' + elem.value);
>                 });

"$$('#something')"

while valid, is almost always wrong. It says "give me a list of all
the elements with id 'something'". But by definition there can be only
one such element, so it is simpler to replace your code with

elem = $(''theme_choice');
if (elem.selected) ...

If you are using this because you have multiple entities with the same
id, then your page is not valid HTML, and browsers may not behave
identically with it.