Gauss said:
I wasn't able to get this working the way you described it.
If I put @{hp_temp} in the token settings bar's second box, it doesn't work.
I have to put it in the attribute's second box.
Additionally, if the value is 0/@{hp_temp} (ie: 0/0) there is still a (empty) bar.
The method I was describing above achieves the same result I saw with your method, except there is no denominator (12/0 is displayed as "12").
It sounds like it's working the way I described and intended! Unless I'm misunderstanding you.
The point is to be able to have a full bar showing if there are any amount of temporary hit points available. It will be a full bar whether it's 1 temporary hit point, or 20.
E.g. If you want to use Bar2 to show a full bar whenever there is any amount of Temporary Hit Points, then you would open the Token Settings for the character, and link the Bar2 attribute to 'hp_temp', set the current amount of temporary hit points in the Bar2 'current' (left) field, and set the Bar 2 'max' (right) field to '@{hp_temp}':

On testing, I realized that you'll have to manually change the token bar value one time for the sheetworkers to actually update and display the bar. After saving the changes on the token, it looks like this:

As soon as I enter '20' into the Bar2 bubble again, it shows like this:

And what is interesting is that the Bar2 'max' field on the Token Settings page will automatically update and show the 'current' value, but the attribute is actually still there, as long as you don't change either of the Bar2 fields from the Token Settings page - make sure to only update the Temporary Hit Point value from the Bar2 bubble. (I just found this out, so I'll update the Tips & Tricks post as well).
But changing the Bar2 bubble to '0' makes the blue line disappear, showing that there are no more Temporary Hit Points available:
