The last third of #207, and the only part that remembers anything.
An admin turns a setting on for people who are already here -- which a default
cannot do, since a default only seeds an account that has none -- and readers
may still turn it back off afterwards, which enforcement does not allow. The
difference between the two is entirely in the remembering.
Each change carries its own version, and an account stores the ones it has had
in its own settings file. Ids rather than a high-water mark, so a change dated
earlier than one already applied is not silently skipped -- the reporter's
analogy is a schema migration, and this is that shape.
Per account rather than per device, because ihasmail's settings are not
browser-local: they live in a file in the reader's own JMAP Files, with the
browser holding a cache. Signing in on a phone does not apply everything a
second time.
A change reaches somebody who had already decided otherwise. That is intended
and confirmed on the issue: the point is to reach everybody who is already
here. It is applied once, and their next decision sticks.
One `update` for however many are pending, since each would otherwise push a
settings file of its own. Enforced values still win, being applied after. A
change whose settings this build does not have at all is dropped rather than
recorded, or it would never run on the ihasmail that does have them.
The reader is told. A setting moving under somebody without a word is the part
of this worth being uneasy about, so the count is toasted with a way into
Settings.
README gains the Docker half the user asked for: a mounted policy file, the
same thing as environment variables for a deployment with no volume, a compose
fragment, and the fact that a policy is read once at startup so editing it
means a restart.
Closes#207.
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