[whatwg] RWD Heaven: if browsers reported device capabilities in a request header (Boris Zbarsky)
Ashley Sheridan
ash at ashleysheridan.co.uk
Mon Feb 6 14:21:30 PST 2012
On Mon, 2012-02-06 at 22:16 +0000, Kornel Lesiński wrote:
> On Mon, 06 Feb 2012 20:00:45 -0000, Irakli Nadareishvili
> <irakli at gmail.com> wrote:
>
> > 1. Adaptive images:
> > To optimize user-experience on smart-phones (most of which have
> > relatively small screens, and are on slow connections most of the time)
>
> Be careful with generalizations like that.
>
> Mobile devices can be connected to high-speed networks. Laptops can be
> tethered via mobile networks.
>
> There are many permutations of screen size, DPI, zoom, network speed,
> bandwidth cost and memory availability that influence decision what image
> resolution is best, and it's not as simple as "mobile" vs "non-mobile".
>
>
> There aren't even clear "device classes". Basic device characteristics
> like physical screen size and presence of a hardware keyboard can change
> dynamically!
>
> Smartphones can be connected to TVs and projectors. Tablets can be
> connected to keyboards. Laptops can be flipped into tablet mode. Desktops
> can have touchscreens — and these aren't obscure things. It's iPad with
> AirPlay and dock. It's most tablet PCs. You can expect many laptops to
> have touchscreens soon.
>
> "Mobile" or "smartphone" can mean anything from Opera Mini on GPRS
> connection to a quad-core 4G smartphones more powerful than desktops were
> few years ago.
>
>
> I appreciate optimisations you're trying to make, but simply reporting
> basic capabilities in an HTTP header isn't going to work well in other
> than few most common cases.
>
> I hope we could come up with a better solution that can all the
> optimisations and improved experience you want to achieve, but doesn't
> have pitfalls of assuming that slow networks and touch screens go
> hand-in-hand, or that devices with keyboards also have mouse and < 100dpi
> screen, etc.
>
>
> > 2. Adaptive CSS/Javascript.
>
> CSS has media queries already. New queries can (and I think should) be
> added to query more capabilities like presence of a touch screen (Mozilla
> experiments with -moz-touch-enabled media query already).
>
> Media queries are dynamic and can be observed by JavaScript, so when you
> switch from tablet's own touch screen to an external display, pages could
> theoretically switch UI too.
>
> > If server could easily detect device type/capabilities it would have the
> > ability to tailor aggregated js/css files to a class of a device, thus
> > providing greatly improved experience.
>
> Sure, but it doesn't mean that the server has to do that and that it's the
> only way to do that. For example:
>
> <script src=touch-ui.js media="input-type: touch">
> <script src=mouse-ui.js media="input-type: mouse">
>
> (although I'm not suggesting using that form literally, as it has some
> drawbacks of its own)
>
> Next version of JavaScript is going to have modules, which makes loading
> of JavaScript cleaner than <script>. Perhaps modules could be loaded
> conditionally based on media-query-like declarations?
>
I can't remember where right now, but I do recall seeing an article
which said that it was a common misconception that mobile devices were
most often on a slow connection. Personally, I tend to make most use of
my mobile for browsing when I'm on a wireless connection. Just because
someone is using a mobile device, it doesn't naturally mean they are on
the move.
--
Thanks,
Ash
http://www.ashleysheridan.co.uk
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