Re: User agent context for rendering the presentation

On Fri, Aug 22, 2014 at 4:48 PM, Jonas Sicking <jonas@sicking.cc> wrote:

> On Wed, Aug 20, 2014 at 7:36 PM, Mark Watson <watsonm@netflix.com> wrote:
> > On Wed, Aug 20, 2014 at 6:49 PM, Jonas Sicking <jonas@sicking.cc> wrote:
> >>
> >> On Wed, Aug 20, 2014 at 6:06 PM, Mark Watson <watsonm@netflix.com>
> wrote:
> >> > So, I'm no so much interested in whether it uses an existing
> >> > Presentation
> >> > API session or not. Let's just assume it doesn't.
> >> >
> >> > So the browser on the TV is freshly navigated to www.netflix.com.
> What I
> >> > meant by the TV being logged in to Netflix account N9 is that cookies,
> >> > IndexedDB data etc. for www.netflix.com is present indicating that
> it is
> >> > logged in. It would then be the sites decision, when launched in
> >> > presentation mode and after communicating with the controller, whether
> >> > to
> >> > stay logged in on that Netflix account or log in on the same Netflix
> >> > account
> >> > as the controller. I would very much like to be able to handle the
> case
> >> > where the controller is using the same Netflix account as the TV
> without
> >> > having to do a new Netflix log-in.
> >> >
> >> > So, I'm saying that IndexedDB, if supported, should not be cleared
> each
> >> > time
> >> > a new presentation session starts.
> >>
> >> I think this falls under the umbrella of "connecting to applications
> >> already installed on a TV".
> >
> > No, I'm just addressing the straightforward 2 UA case and the question -
> > which I thought was the subject of this thread - about whether the
> browsing
> > context at the "presenting" UA is a "fresh" one (like incognito mode) or
> > might have previously stored data for that origin.
>
> If you are using data that's on the TV, you are effectively connecting
> to existing applications there. The fact that those applications
> happen to have been implemented using web technologies doesn't really
> affect many of the complexities involved.
>

​Again, I'm thinking of the 2-UA case here, where the presenting device has
a real, fully-fledged UA. It doesn't matter what that UA is running on (TV,
another laptop, whatever), it has the APIs of the web platform, including
IndexedDB.

There is another use-case, where the presenting device does not have a UA,
but does have various apps that can render certain kinds of content. This
is important too (actually, more important, since these devices already
exist in their millions), but not the subject I was addressing here.​


> > It had been suggested that we mandate something like incognito mode,
> where
> > IndexedDB etc. are cleared on the presenting UA before the presentation
> page
> > is loaded. I'm objecting to mandating that, on the grounds described
> above.
> > Of course if we don't mandate it, then people would still be free to
> > implement it that way, but that would also be free to implement a UA with
> > persistent IndexedDB like on desktops/laptops and the latter would have
> > better UX in many cases (IMO).
>
> The incognito mode discussion was around the 1UA case. I.e. that when
> the presentation page runs on the controlling device, it's important
> that it doesn't have access to data from the controlling device.
>

​I think this is too restrictive for the 1 UA case. Of course the
presenting page should not have access to the IndexedDB data stored ​by the
controlling page, but I see no reason why it should always start with an
empty IndexedDB. Why can't it see the data it stored there last time it ran
?


> I'm ok with leaving the 2 UA case undefined for now. I.e. I'm ok with
> letting the spec leave it up to UAs to decide if the page which runs
> on TV will see data from the TV or not.
>
> I think the main hurdle to enabling using data from the TV will not be
> specification text. The main hurdle will be getting hardware vendors
> to support this. Any help here would be greatly appreciated.
>

​I think the TV vendors might reasonably expect the use-case of connecting
to apps on the TV to be addressed before the use-case of connecting to a
fully-fledged UA on the TV, since the former is already widely deployed.

...Mark​



>
> / Jonas
>