I am a longtime Domino developer, relatively new to XPages.  The requirement is quite simple, although, I have never been able to find anyone else who has even tried this...

 

Basically, validate one set of attachments, pdf's only, based on how many pages are in each file.  So, if the limit is 25 pages, this is how it works:

1. attach file #1 - 10 pages.  OK.
   
2. attach file #2 - 10 pages.  OK.
3. attach file #3 - 7 pages.  OOPS!  Sorry, you've gone over the 25 page limit.  Please try another.
4. attach file #4 - 5 pages.  OK.

At this point, the user can't attach any more pdf's, unless some are removed.  This is in several file uploads, but the totals are for the entire web form.

 

I've been able to do this in traditional Domino, using a small java applet to return the page counts, and javascript to update the total before validating.  Is there any way to do this with SSJS or other way?  Note that the pdf file shouldn't be saved at all if it goes over the limit.