Display count of records in drawer

I would like to show the count of the sub-records in a drawer. This will be a flag to the user that there are related records and they should open the drawer. 

I have two basic models on my page. The drawer is working properly. Just want to get this count. 


Here’s an example using Accounts and Contacts.

Additionally, you can create a rollup field on the main records for the count of records in the drawer to conditionally render the row action. ie. contactCount > 0

Amazingly simple. That’s great! Thanks.

Quite  welcome.

Pat is the man!