Re: [Task Scheduler] scheduling flexibility

On Tue, Nov 12, 2013 at 9:51 PM, Christophe Dumez
<ch.dumez@sta.samsung.com>wrote:

>
> On 11/12/2013 10:28 AM, Christophe Dumez wrote:
>
>
> On 11/12/2013 07:08 AM, John Mellor wrote:
>
> Skipping the user notification variant for now seems reasonable - it would
> probably be best to integrate that into a v2 Web Notifications API.
>
>  However I'm worried about highPrecision serving as a hint. If your app
> needs highPrecision, it's often essential that the timer happens at that
> exact moment, and inexact scheduling often wouldn't be useful. Hence I'd
> rather have add(...) throw an error if you request highPrecision and it
> gets denied (the app can of course catch this and add a non-highPrecision
> alarm if that would be good enough). This should be easy, since add already
> returns a Promise that can fail with QuotaExceededError or UnknownError; we
> just need to add a new HighPrecisionDeniedError.
>
>
> I guess could be convinced either way. The reason I proposed to use it as
> a hint and not throw was to match an existing API I am familiar with and
> that has pretty much the same use case: the Geolocation API:
> http://dev.w3.org/geo/api/spec-source.html#high-accuracy
>
> Also, I am not a big fan of throwing exceptions unless strictly needed
> because developers tend to forget about handling them.
>
>
> Alternatively to throwing an exception, which is synchronous and therefore
> might cause trouble (if the implementation determines asynchronously if it
> can satisfy the highPrecision request). The client could check the
> highPrecision attribute on the ScheduledTask object that is returned
> asynchronously:
>
> e.g.
>
> navigator.taskScheduler.add(Date.now() + 6 * MS_PER_HOUR, {highPrecision: true; /*hint*/}).then(function(task) {
>   if (task.highPrecision) // Actual value
>     // Request was satisfied.
>   else
>     // Request was not satisfied.
> });
>
> Would this make sense?
>

As I said earlier<http://lists.w3.org/Archives/Public/public-sysapps/2013Nov/0076.html>,
<<By "throw an error", I just mean immediately reject the promise (call the
onRejected callback passed to Promise.then/catch, if any). If the author
doesn't provide an onRejected callback, nothing happens.>>

Rejecting the Promise can be done asynchronously.


> Kr,
>
> --
> Christophe Dumez - Samsung Telecommunications America
>
>