internalcalc Necessary facilities

internalcalc Necessary facilities

I'm using "unidac" comps for "delphi" with "tclientdataset"
I want to use "unidac" comps without "tclientdataset"
before I was use it with "tclientdataset" and use internalcalc  field as
in-mem field
I was change it whenever i want
"Devart" add internalcalc field in version "unidac9.4.0"
but it work like calculated field it set to null before every call of "onCalcFields"
I want to set it one time and field save this value until other change