Re: What's wrong with UA sniffing and server side processing?.

On 28 June 2013 12:04, Marcos Caceres <w3c@marcosc.com> wrote:

>
>
> On Thursday, June 27, 2013 at 2:34 PM, Darrel O'Pry wrote:
>
> > <unlurk />
> >
> > There seems a be a general dislike for UA sniffing, but I don't see much
> reasoning behind it. Why are people opposed to UA sniffing? What's wrong
> with UA sniffing to do device detection and determine device
> characteristics?
> See:
>
> https://developer.mozilla.org/en-US/docs/Browser_detection_using_the_user_agent
>
> For example:
>
> http://blogs.msdn.com/b/ieinternals/archive/2011/06/30/perils-of-user-agent-sniffing-browser-mode-document-mode-compatibility-view.aspx
>
>
I think UA sniffing is never going away but I'd prefer to see it only used
for limited cases e.g. where we want different markup for different UAs and
feature detection doesn't deliver.

The examples I can think of are replacing async/defer on script elements
and the proposed lazyload attribute on images with JavaScript loaders for
older UAs rather than always using JS.

That said where feature detection can be used I'd prefer to use it but
there areas where it may not be the most appropriate solution.



> > I understand reservations about server side processing, particularly
> when you don't have access or control over the server?
> Yes, this affects a significant number of developers (at least the
> research we - RIGC- has done seems to suggest this… speaking of which, I
> don't know where the link to that research went. Would be good to have that
> in the Wiki and if there is supporting research, would be good to add to
> the wiki too).
>

Without some understanding as to who completed the survey I think we have
to be careful what conclusions can be drawn from the results. Do we have
any ideas what sort of organisations the respondents came from and what
size sites they run?

I can understand the need to avoid a server-side solution for things like
epub but I wonder how much the desire to avoid a server-side approach is
limiting the possibilities for a solution (not that I've got an magic
answers there).

Cheers

Andy