Re: [Evolution] Calendar: recurrence, exceptions and occurrences

["D. D. Brierton" <darren dzr-web com>]

On Wed, 2004-03-03 at 18:56, Dan Winship wrote:

> Sure, but you wouldn't just tell the students "because of conflicts, we
> won't be meeting on day X". You'd explicitly say "but we will make up
> the lost time by meeting on day Y" or something. The problem is that evo
> doesn't let you make that clarification.

Right -- my problem may be purely with the wording of those parts of the
Recurrence tab. I was genuinely confused by it.

> You guys have weird commercials. :-)

Oh we're weird in all kinds of ways :-)

> > In summary, I think that if you are using "until <date>" in your
> > recurrence rule then an exception should indeed be a cancellation.
> > However if you are using "for <n> occurrences" then an exception should
> > be a postponement.
>
> Well, I can come up with examples where that would be the wrong thing
> too. In the university example, another professor might already have the
> room booked during your time slot starting the week after your class was
> supposed to end, so you have to switch the class to Mondays instead of
> Wednesdays for the two "extra" weeks.

Right. I hadn't thought of that. The kinds of classes I had in mind are
normally *very* small and so are taught in the office they loan me. No
room booking required. But you are right.

> In that case, an interface that
> treated exceptions as postponements would be a pain to deal with, but
> one that let you add and remove instances as you needed [which evo
> doesn't completely do right now] would work fine.

Obviously there is no point looking at this any further until 2.0 comes
out. I haven't been testing 1.5.x so I don't know if the interface has
changed at all. But after 2.0 comes out I might post a usability bug for
that part of the new appointment dialog, as I genuinely was surprised by
what it did. It's clear that the choice of "exception" and "occurrence"
is based on something in some spec, because Mozilla Calendar is almost
identical in its use of these terms when specifying an event's
recurrence. Perhaps just a better choice of words could be found.

As for whether the actual functionality could be altered, I don't know.
It's hard to imagine how to add more options to the dialog without it
becoming hugely bloated and unwieldy. What are the usage scenarios?
Would one ever want a choice as to whether an exception was treated as a
cancellation or a postponement if the rule is "until <date>"? I can't
think of any. As we've shown, there are scenarios where one might want
either cancellation or postponement for exceptions to a "for <n>
occurrences" rule. But thinking of a clean simple way of allowing a user
to specify which is pretty hard. Perhaps Anna would have an idea?

Best, Darren

-- 
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D. D. Brierton            darren dzr-web com          www.dzr-web.com
       Trying is the first step towards failure (Homer Simpson)
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