Re: [SMW-devel] Recurring Events Calendar Format

[John M. <jmc...@hy...>]

1. My initial question -- I was asking for some realistic use cases,
particularly having 'thousands' (or even hundreds) of repetitions.

2. The Book Use Case -- (ok, there's 3*20 = 60 meetings) -- why not
pre-calculate the specific event dates using a template and or parser
function, rather than re-calculating them each and every time the
[[category:Event]] article is read by the {{#ask:}} extension? It's far, far
better performance for the system, and it's as hidden from view as any other
template-formulated property.

3. Multiple attribute instances - whew, I'm relieved to hear that!

4. Date arithmetic -- no I am instead talking about integrating function
calls (like date arithmetic) directly into the {{#ask:}} format so that the
result is displayed in a table column, for instance.

Thinking back, the reason I commented originally was that I believe a
<calendar> widget is a more robust solution than {{#ask:}}. At the same
time, I couldn't be in more agreement that a calendaring facility for
repeating events is sorely needed. It's best though to remain as mindful as
we can of the costs and consequences of any approach.

- John
  -----Original Message-----
  From: Yaron Koren [mailto:ya...@gm...]
  Sent: Friday, April 03, 2009 9:54 AM
  To: John McClure
  Cc: sem...@li...
  Subject: Re: [SMW-devel] Recurring Events Calendar Format


  I don't quite understand your initial question: a repeated event can have
thousands of repetitions, so it wouldn't be practical to specify them all
manually; meanwhile, #ask is just how data is retrieved within SMW.

  You do point out one weakness in the scheme I'm proposing, although I
don't think it's a major one: that it doesn't let you have more than one
data property on the page that's the recurring event. To show why I don't
think it's a big deal, let me illustrate with your example: for a book, all
the dates you listed are most likely single events. But let's say one of
them is repeated, like there's a daily editing meeting for several months.
In that case, you can create a page called "[Book name] editing meeting",
and have all the necessary repeating-event properties on that page, instead
of on the book's own page. Which I think is natural anyway: if any sort of
event happens on a regular basis, it's probably important enough to have its
own page.

  To your other question - I don't know about all the formats, but I think
most handle multiple values per property. Semantic Google Maps does, and I
think the 'calendar' format does as well - if it doesn't, it should.

  Date arithmetic can, and I think should, be done by parser functions
outside of SMW - I don't know of any extensions that do it at the moment,
but it would definitely be a good idea for an extension.

  -Yaron



  2009/4/3 John McClure <jmc...@hy...>

    Hi Yaron,
    It's not so much what sf/smw can or can't do -- it's about whether
{{#ask:}} is the right approach for repeating event. #ask is presently used
to query articles having *any* date-property. So what benefit actually is
there to having repeatable events handled by #ask? I can think of just ONE
BENEFIT: a user does not need to specify multiple date-properties for an
article. Maybe there are others?

    Here's the bigger problem though. Lets say we have an article about a
book. The article contains many, many dates -- dates for composition,
editing, proofing, publishing, shipping, distribution, etc. If
repeat-properties are present for the article, which action is being
"repeated"? Or maybe is the book itself somehow being "repeated"?

    So my concern is that -- yes while technically possible -- hardcoding
repeat-event properties for an article kinda leads to many questions about
the data model you're assuming/looking for.

    I'm curious, does #ask today handle multiple instances of a named
property for an article, or does it just look for a single instance? Does
the calendar format accurately show those multiple values?

    Hmm, if you'd like to bring #ask to a 'new level' that involves dates,
might I suggest that a useful generic function would be to perform date
arithmetic, eg difference(dated-property-1, dated-property-2,
units-selection), and output the result. Or something like that. I'm not
thoroughly knowldegeable about #ask, so maybe that's already there. Another
example that ties right into the calendar option would be
duration(dated-property-1, dated-property-2), which would bracket the two
dates in an interesting way. Maybe that's there with the timeline option --
I havent studied it all enough yet.

    Thanks



    ------------------------------------------------------------------------
------

    _______________________________________________
    Semediawiki-devel mailing list
    Sem...@li...
    https://lists.sourceforge.net/lists/listinfo/semediawiki-devel