Re: The Rubber meets the Road - DNT compliance code

Or, "Is this UA mobile? If so, redirect to the mobile site"

Again, this is neither new nor hard.

On Wed, Jun 13, 2012 at 8:22 AM, Ian Fette (イアンフェッティ) <ifette@google.com>wrote:

> Many websites already do this -- "serve this JS to this user agent". It is
> neither complex nor hard.
>
>
> On Wed, Jun 13, 2012 at 7:44 AM, Peter Cranstone <
> peter.cranstone@gmail.com> wrote:
>
>> All,
>>
>> There's a lot of questions around a non-compliant UA sending a DNT
>> header. There's still no definition on the forum or the spec on what
>> constitutes a non compliant UA, or even who is going to maintain a
>> "blacklist" of those non-compliant UA's. Finally there's no description of
>> a message that should be sent back to the consumer indicating that he's
>> using a non-compliant UA.
>>
>> So I'm posting a link today of what something might look like running on
>> a server. The reason this is in PHP is because there are lot of servers (in
>> the 10's of millions) that cannot suddenly start adding server side modules
>> that do the detection. So it will all have to be done via a script.
>>
>> Think about this for a moment. In the real world server side admins are
>> going to have to add code to EVERY CGI script to do this. The performance
>> hit is going to be HUGE.
>>
>> Here's the link: http://www.5o9mm.com/mod_dnt_test_1.php
>>
>> We've blacklisted the following browsers:
>>
>> HTTP_DNT_BLACKLISTED_USER_AGENT_1 = Mozilla/4.0 (compatible; MSIE 7.0;
>> Windows NT 6.1; Trident/5.0)
>> HTTP_DNT_BLACKLISTED_USER_AGENT_2 = Mozilla/5.0 (compatible; MSIE 9.0;
>> Windows NT 6.1; Trident/5.0)
>> HTTP_DNT_BLACKLISTED_USER_AGENT_3 = Mozilla/4.0 (compatible; MSIE 7.0;
>> Windows NT 6.0; Trident/5.0)
>> HTTP_DNT_BLACKLISTED_USER_AGENT_4 = Mozilla/5.0 (compatible; MSIE 9.0;
>> Windows NT 6.0; Trident/5.0)
>> HTTP_DNT_BLACKLISTED_USER_AGENT_5 = Mozilla/5.0 (Windows NT 6.0;
>> rv:8.0.1) Gecko/20100101 Firefox/8.0.1
>>
>> So every time someone hits the Web site we have to run a check. The
>> request time for this check on our server is:
>>
>> REQUEST_TIME = 1339597469
>>
>> For that single page. Now multiply that by every page on your Web site
>> that is scripted. Ouch.
>>
>> Now here's where it gets really interesting. Let's say that I'm on the
>> blacklist. What does the server do? By rights it should abort the entire
>> request and send a 400 invalid request response back to the user.
>>
>> So what the heck does the user do now?
>>
>> If this spec is going to be Trusted and used it has to work in the real
>> world which is NOT 100% technical. They turn it on (or have it turned on
>> for them) and they expect magic. They don't expect to be told that there
>> browser is non-compliant and they can either go get another one or get
>> tracked.
>>
>>
>>
>>
>> Peter
>> ___________________________________
>> Peter J. Cranstone
>> 720.663.1752
>>
>>
>