I created a function getAge in global events which calculates a persons age from their id
the id is stored in the users table in the field 'personalcode'
I want to create a custom field that will display the user's age
I can do this in row_rendered like this
getAge($this->personalcode->CurrentValue)
but for tidiness i would rather have it directly in the custom field
What would the correct expression be for that, assuming its possible?