When i wrote the functions to import contact, i already created a couple
of “temporary” functions to validate whether the input given from the
Excel files was correct according to the various domains used in the
relations, so i can know whether i can import that data.
I realized that i could do exactly the same when validating forms: check
that the value conforms to the domain, in the exact same way, so i can
make sure that the value will be accepted without duplicating the logic,
at the expense of a call to the database.
In an ideal world, i would use pg_input_is_valid, but this function is
only available in PostgreSQL 16 and Debian 12 uses PostgreSQL 15.
These functions are in the public schema because initially i wanted to
use them to also validate email, which is needed in the login form, but
then i recanted and kept the same email validation in Go, because
something felt off about using the database for that particular form,
but i do not know why.
