Custom Function to increment a value by one

Custom Function to increment a value by one

Hi,

I'm trying to find a solution to set up a counter on CRM records that tracks how many times certain actions have taken place. As a specific example:

We have a field on Deals called "Times Close Updated". This starts at 0 on record creation. I'd like this field to automatically increase by 1 whenever a user edits the "Closing Date" field of that specific record. This doesn't seem to be possible via a Workflow Rule directly (I can set the field to a specific number, but can't set it to {previous value}+1.

It seems straightforward to set up a custom function that will run every time such an edit takes place, but I'm not familiar with Deluge and haven't found any suitable code online that I was able to successfully modify to get what I want. Do you have any advice on how I'd go about doing this? In particular, I'm not clear on the scope of Deluge's custom functions and wasn't able to find a clear answer. Does a function that's triggered by a Workflow Rule run only on the record that triggered it, or does it run globally on everything?

Thanks!