I have a mandatory Text field with the following validation rule formula.
Visitor1=='' && (isNullOrEmpty(trim((Visitor1FirstName))||Visitor1FirstName =='') && (Visitor1LastName!='' || Visitor1Organisation!='')
It work perfectly, if the these three fields were empty when Visitor1 is not selected. However, if a space was entered to any of these fields, somehow it ticketed the blank space as a value and bypass the validation.
So how to validate the blank or whitespace in Nintex form Text field?