Re: Activity (state)

There have been a few ideas on how to express this kind of state. The
current model relies on the use of the startTime/endTime/published
properties but that can be ambiguous. Essentially the heuristic is:

1. If there is no startTime/endTime, the activity is assumed to have
occurred in the past ... at a point at or before the published time
(if provided). The implicit assumption is that published is always
either right now or in the past.

2. If there is an endTime that either indicates right now or past, the
activity occurred in the past.

3. If there is a startTime that either indicates right now or past:

  a. And there is no endTime, the Activity *can be assumed* to either
      have occurred in the past or is still ongoing.
  b. Or there is an endTime that indicates the future, the Activity is
      assumed to be ongoing

3. If there is a startTime that indicates a future date/time, the
Activity is pending.

Obviously, this is an imperfect model but given that Activities have,
for the most part, been used primarily to record Activities that have
already occurred, the rules haven't proven to be much of a problem.

That said, other suggestions have been made.

A. An earlier version of the AS2 spec had a "state" property whose
value was an enum explicitly identifying various activity states (e.g.
completed, pending, cancelled, aborted, etc). It was removed due to
lack of clear supporting use cases

B. We could leverage JSON-LD's @type to indicate the status, i.e.
{"@type": ["Activity", "PendingActivity"], ... }. This could work, but
would imply that an object's type changes as the status of the
activity changes, which can be a bit strange (object types are
typically immutable).

If we wanted to explicitly identify the status of the Activity rather
than using the startTime/endTime heuristics, then I would go for
option A, we would just need to identify the specific states required.

- James

On Mon, Jun 29, 2015 at 5:00 AM, Renato Iannella
<ri@semanticidentity.com> wrote:
> [Apologies if this has already been discussed…]
>
> The definition (note) for Activity in [1] says "An Activity is a subclass of
> Object that describes some form of action that may happen, is currently
> happening, or that has already happened.”
>
> There seems to be three states (may/current/past) to an Activity but no way
> to express this in syntax?
>
>
> Cheers...
> Renato Iannella
> Semantic Identity
> http://semanticidentity.com
> Mobile: +61 4 1313 2206
>
> [1]
> http://jasnell.github.io/w3c-socialwg-activitystreams/activitystreams2-vocabulary.html#types

Received on Monday, 29 June 2015 15:21:46 UTC