Hi,
Using a Business rule can be done, but without a Client script or an UI policy the user will not have any indication that that field is mandatory.
So it might not be the best user experience, to have an error message stating invalid insert, without first showing which field should be filled in.
To make a field mandatory with a business rule you can write something like below example.
(and this simple example doesn't even need to use script, it could be done with conditions filter and actions alone.
Business rule runs before insert
(function executeRule(current, previous /*null when async*/) {
if (!current.getValue('description')) {
gs.addErrorMessage('Description is mandatory, cannot be empty');
current.setAbortAction(true);
}
})(current, previous);
