Re: [Jmap] Hacker News Discussion - getMailboxes single data set vs tree primitives or paging

[Neil Jenkins <[e-mail]>]

When considering this before, I've tended to observe the
following points:
 * Standard mail clients generally fetch all mailboxes up front, and
   indeed often need to before they will display a (non-loading) UI.
 * The vast majority of users have very few folders (from what I
   remember last time we ran the stats at FastMail, well over 90% of
   users never created a single extra folder beyond the defaults).
So I therefore left out querying mailboxes (and so being able to fetch
them in pages) from the initial JMAP draft. The main case for this seems
to be presenting access to usenet groups or other non-strictly-email
stuff. There is always a question of whether we want to support every
use case, at the expense of making implementation more onerous.
Having said that, there's a standard mechanism in JMAP for doing
querying/sorting/paging of a record type (getFooList[1]), so if we do
decide we want this capability it is mostly obvious how it should be
specified. We'd include a filter option for *parentId* so you could
easily fetch as a hierarchy if you want, and it would be easy to add an
isArchived flag or similar later and filter on that if desired.
As long as we still allow *getMailboxes* to be called with a null *ids*
argument (therefore returning all mailboxes), clients can still just
ignore all this if they always need to fetch the whole set up front.
It's mainly therefore an extra burden on server implementations. So is
it worth the tradeoff? Thoughts?
Neil.

Links:

  1. http://jmap.io/spec-core.html#querying-data