TYPO3 Core

I added a custom checkbox field to a Powermail content element that will trigger submitting the form data to an external API. I wanted to validate that the form has the necessary fields required by that API, and simply wanted to use a user function in the eval configuration.

Unforunately checkboxes do not allow user funcs in TYPO3 v12: https://docs.typo3.org/m/typo3/reference-tca/12.4/en-us/ColumnsConfig/Type/Check/Properties/Eval.html

It would be nice if I could use custom user evaluation functions (tce formevals) with checkboxes.