RE: PositionOptions.timeout & UserAgent permission

Doug's interpretation sounds the most sensible to me - you cannot expect that gaining permission is going to take less time than the site expects for getting a result.  In either case, the site should still be given the option of using window.setTimeout() if there is an absolute requirement.  Hopefully, gaining permissions will be a one-off situation for a site and permission can be gained before any time-critical operations are necessary (i.e. at registration or login time, rather than when there is an emergency in progress).

> -----Original Message-----
> From: [mailto:public-geolocation-
>] On Behalf Of Andrei Popescu
> Sent: Monday, 16 March 2009 11:48 PM
> To: Greg Bolsinga
> Cc: public-geolocation
> Subject: Re: PositionOptions.timeout & UserAgent permission
> Hi,
> You're right, the interaction between timeout and user permissions
> needs to be clarified.
> We have two choices for when the timer starts:
> 1. At the moment of the call. This is what the spec says right now.
> In this case, the following would happen when the timer fires (i.e. we
> failed to get a position fix in the given time interval):
> 1.1 The user permission was already given prior to the call. When the
> timeout expires, the error callback is invoked with TIMEOUT.
> 1.2 The user permission was unknown at the moment of the call... (the
> implementation started the location acquisition process (warms up the
> GPS / fires a request to a server / etc) and also asked the user for
> permission.)
>   1.2.1 The timer expires before the user has time to react. The error
> callback is invoked with TIMEOUT.
>   1.2.2 The user allows permission and later the timer fires. The
> error callback is invoked with TIMEOUT.
>   1.2.3 The user denies permission before the timer expires. The error
> callback is invoked with PERMISSION.
> The problems I see with this scenario:
> - In case 1.2.1, what will happen to the UI once the error callback
> has fired? If the call was a one shot request (getCurrentPosition()),
> then the UI is now irrelevant as no matter what the user decides, the
> call has already failed.
> - The implementation does some work before the user permission is
> granted. This is all useless if the permission is later denied.
> The other choice we have is:
> 2. The timer starts once the user permission is given. This can be at
> the moment of the call if the permission was given already or later,
> once the user interacts with a UI widget. This is Doug's
> interpretation of the spec.
> 2.1 The user permission was already given prior to the call. When the
> timeout expires, the error callback is invoked with TIMEOUT.
> 2.2 The user permission was not given at the moment of the call...
> (i.e. the implementation asked the user for permission but didn't do
> anything else).
> 2.2.1 If the user denies permission,  the error callback is invoked
> 2.2.2 If the user allows permission, this case is equivalent to 2.1
> The 2.* scenario doesn't have the problems with 1.*. We do need to
> explain though that the timeout interval does not apply to the time it
> takes for the user to grant the permission. It only applies to the
> time it takes the implementation to acquire a location, once the
> permission is given. However, here we also have a problem: in some
> cases, the developer has an overall constraint on the time it takes to
> get a position fix. This constraint is a property of the application
> and applies no matter what causes may prevent the position to be
> acquired (including user / UI slowness!). In this scenario, the
> developers would be forced to use a separate window timeout, which
> defeats the purpose of having a timeout in our own API.
> I feel that the usecase mentioned in scenario 2 is the likely usecase,
> therefore I think it's best to stick to choice 1, given that
> implementations can find reasonable solutions for the problems I
> mentioned above.
> On Sun, Mar 15, 2009 at 7:32 PM, Greg Bolsinga <>
> wrote:
> > I'm afraid I still think that timeout, the old lastPosition, and
> maximumAge
> > are still muddly. These are all implementation details. All the
> developer
> > wants is a position. Developers may basically either want a precise
> position
> > or a lazy position.  And when I think of developers, I do no think
> many are
> > going to want the lazy position at all.
> I can think of at least one set of developers who want the lazy
> position :)
> > Why not just give them less options
> > instead of more that they will always set to precise?
> If they only wanted the precise position, I'd be all for removing the
> option. But given the previous point, I think we want this flexibility
> :)
> Thanks,
> Andrei

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Received on Monday, 16 March 2009 22:24:50 UTC