Currently, the routine to set values in appserver only tests if the provided
value can be converted to the correct data type (i.e. whether it is a valid date
etc.). Neither strings nor numbers are checked for length. Handling too long
strings or too big numbers is completely left to the backend.

It would be preferrable if appserver tested for length of strings, for length of
numbers and would probably even round numbers to the allowed fractional part
before passing the data to the backend.