The first two thirds of #207. A school wanting "warn about outside senders"
on for three thousand pupils cannot ask three thousand pupils, and the
reporter is right that this is a company policy rather than a preference.
Two powers, and the difference between them is the whole request. `defaults`
seed an account that has never had settings of its own and can be changed
afterwards like anything else -- a starting point, not a rule. `enforced` are
reapplied on every load and cannot be changed at all.
Enforced controls stay visible and go dead, with a line saying why. The issue
asked for that by name: a control that is simply missing reads as a bug to
somebody who has used ihasmail without a policy.
The lock is in the settings store rather than only on the controls. There is
one door -- `update` -- and putting it there means an imported settings file,
a settings file synced from a device that predates the policy, and a control
somebody adds later and forgets to check are all covered by construction.
Reset goes back to the installation's answer rather than to ihasmail's, so it
cannot be a way around a policy either.
Configured by environment variable or by a file, because ihasmail's own
production runs read-only with no volume: an installation that cannot mount a
file can still set a variable. Keys this build does not have are dropped, the
same rule an imported settings file already gets -- a policy written against a
newer ihasmail must not put a setting nothing reads into everybody's synced
settings file. Malformed JSON stops the server rather than quietly doing
nothing, since a policy that silently did not apply is indistinguishable from
the feature not working.
Tier three -- enforcing a setting once while still letting readers change it
afterwards -- is not here. It needs a decision the reporter and I have not
made yet, and it is the only part that stores anything new.
Refs #207.
jcoffey-dev
457ea53ca3