[whatwg] RWD Heaven: if browsers reported device capabilities in a request header

[Matthew Wilcox]

Well given that the point you raise is about opting in and out, not about
the capability of fingerprinting itself. Which as you say, already exists.

Can we not turn this into an option in the same way browsers handle
requests to get the users location? With configuration too?

Allow browsers to see my:

screen size

connection speed

…

On 7 February 2012 22:45, Mike Taylor <miket at opera.com> wrote:

> On Tue, 07 Feb 2012 11:32:23 -0600, Matthew Wilcox <mail at matthewwilcox.com>
> wrote:
>
>  , will cause their users to get more broken pages (which is what happens
>>> in many cases with browser sniffing right now), will lock new devices out
>>> of the market (which is what happens with new UA strings right now).  And
>>> hence that the proposal is bad for the web in various ways.
>>>
>>>  I'm not sure what your grounds are for thinking this. Would it not be
>> sensible for the server to have to serve some default if the headers
>> aren't
>> there anyway, the assumption must be that the device can't send these
>> headers. In what circumstances might this cause breakages? And how could
>> it
>> possibly lock out any devices? This is a progressive-enhancement type
>> tech,
>> not a "if you don't have the ability to notify the server you can't get
>> any
>> info" type tech. Surely?
>>
>
> "Progressive-enhancement type tech" gets abused as well. Take the <video>
> element, with its lovely <source> elements for codecs and fallback content
> for non-supporting UAs. No hacks necessary. Then throw laziness and
> javascript at it and you've got a mess.
>
> An example, visit http://www.maerskfleet.com/ with an empty UA string (or
> use Opera). In a browser that should be able to support <video>, you'll get
> a JS error and the page is blank. Even after including Modernizr and using
> HTML5 which is designed to gracefully degrade for older UAs, developers do
> the same old UA sniffing trick: https://gist.github.com/**1761168<https://gist.github.com/1761168>
>
> I would love to believe that all developers would use this proposal "for
> good", as it were. Experience leads me to believe it will be just another
> technique sniffed and served to the regular suspects.
>
> --
> Mike Taylor
> Opera Software
>