Rails - Aug 2006 - Extracting the current value of a DOM element

So, say I have two select boxes. One with the letters of the alphabet, 
and a second with a list of names. When I select the letter in the 
first, how do I, in my onChange function, extract the value I selected 
in the first box, to determine what values to populate the second box 
with?

I don''t want to submit the form, I''d like to do this with
Ajax.

Thanks in advance,
Ben.

-- 
Posted via http://www.ruby-forum.com/.

Ben Brightwell wrote:
> So, say I have two select boxes. One with the letters of the alphabet, 
> and a second with a list of names. When I select the letter in the 
> first, how do I, in my onChange function, extract the value I selected 
> in the first box, to determine what values to populate the second box 
> with?
> 
> I don''t want to submit the form, I''d like to do this with
Ajax.
> 
> Thanks in advance,
> Ben.
<script type="text/javascript">
function alertSelected(selectObj) {
  alert(''selected value is: '' + 
selectObj.options[selectObj.selectedIndex].value);
}
</script>

<form>
  <select onchange="alertSelected(this)" id="letters">
    <option value="a">A</option>
    <option value="b">B</option>
  </select>
</form>

completely untested, but you get the idea. You first need a reference to 
the select element. Then the selectedIndex property will give you the 
index of the selected option and the options property is an array of the 
options.

Dana P

-- 
Posted via http://www.ruby-forum.com/.

Dana Pieluszczak wrote:
> <script type="text/javascript">
> function alertSelected(selectObj) {
>   alert(''selected value is: '' + 
> selectObj.options[selectObj.selectedIndex].value);
> }
> </script>
> 
> <form>
>   <select onchange="alertSelected(this)"
id="letters">
>     <option value="a">A</option>
>     <option value="b">B</option>
>   </select>
> </form>
> 
> completely untested, but you get the idea. You first need a reference to 
> the select element. Then the selectedIndex property will give you the 
> index of the selected option and the options property is an array of the 
> options.
> 
> Dana P
Ok, that works for a static example, but what if I want to send the 
value to the controller? I can''t figure out how to take the
''this''
object and translate it to ruby code.

-- 
Posted via http://www.ruby-forum.com/.