Proposal: Calculation element for Form Builder

Overview

We would like to have a new element that allows basic arithmetic operations with number fields. The idea is to be able to sum up several number fields or compute an average. The implementation might make use of the field references suggested in issue #4576.

It should also be possible to include constants in the computation.

Use case

Trying to set up a scoring form for e.g. an event – it would be great to be able to compute the average score and store it in CiviCRM.

Current behavior

No such behaviour currently exists.

Proposed behavior

A computed form element is available that can use input fields as well as fixed values.