A preliminary enhancement of the Dataform which was surprisingly easy to do. It allows adding formulas to view templates for calculations on numeric values in entries displayed in the view.
For example, the following is an illustration of Dataform-based attendance activity with push buttons for selecting present/absent for each participant, and a column that shows number of attendances for each participant and total in the column header.
The formula tag that does the entry level calculation in this illustration:
%%F1:=||Lecture 1:value||+||Lecture 2:value||+||Lecture 3:value||+||Lecture 4:value||%%
The formula tag for the column total: