Control required values with formulas in Orbeon Forms 4.7

Up to Orbeon Forms 4.6, Form Builder only lets you determine whether a field is required or not once and for all, by saying "Yes" or "No.

With the upcoming Orbeon Forms 4.7, you can also choose to use a formula, which means that the choice can be dynamic: for example, a field might be required only if another field is set to a specific value.

As usual, you express the formula with an XPath expression, which gives you access to all of the form's data as well as the Orbeon Forms XPath function library.

For more details, see the documentation.