Add record count to collapsed region

I have a diagnostics page where I wanted to display how many records are in a collapsible region's title.

The following is a simple solution, but will only work properly if all records are displayed, and no pagination is used.
Otherwise, check this past post for alternative methods to get the number of rows in a region.

Pick a column in the region and add a class. I chose "cnt".

Column attribute

To be selective, it's always handy to add a static ID to the region.

This is not an 'advanced' feature

Now we're ready to create an After Refresh Dynamic Action on the region, executing the following JavaScript, also firing on initialisation

$('#p99_share .t-Region-title').text('Sharing ('+$('#p99_share .cnt').length+')');

It will relabel region title with the amount of .cnt classes it could find in the region.

The final result looks like this:

Collapsible region with modified title

An alternative that skips the need for a static region ID would be

$(this.trigginerElement).find('.t-Region-title')
   .text('Sharing ('+$(this.trigginerElement).find('.cnt').length+')');

After Refresh Dynamic Action

Edit - Trent offered a more declarative example.

Relatively simple, but effective.