custom bbCode tag and variables ($postid) ? possible?

[effgee]

Hi all!

I would like to create a custom bbCode tag [spoiler] that can be collapsed/expanded via JS. In order to be able to do that however, I need to assign unique IDs to each container displaying a spoiler posted by users.

So I was wondering if it was possible to create a custom bbCode tag [spoiler], where the replacement code contains the variable $postid, similar to the snippet below:

<div id="spC_$postid" onclick="JSgoeshere">
  <div class="spBody"> (This just for formatting)
    {param}
  </div>
</div>

("spC_" = prefix so the div doesn't have the same ID as the postbit container)

Any hints/tips/pointers would be greatly appreciated.