attribute checker template & content negotiation

[Peter Schober]

For a site supporting more than one language I setup an attribute
checker template at the SP. (A great feature to support the "federate
freely and catch errors later"-method of getting a service rolled
out.)
This template is making liberal use of mdui stuff, which again may be
provided in different languages.

Which has the side-effect of the template being written in one (static)
language and any variables from that template being replaced with the
language the user agent indicates as preferred (dynamic, via
accept-language).
E.g. a German error template text with English institution names or
URLs or Logos within. Writing that template in English would cause the
same problem, only with languages reversed (English text with German
names etc.).

It's not a big deal and of course we'd like to avoid showing that page
to anyone, ever. Anyway, would adding a mechanism to the SP to make
error templates more dynamic be a desirable feature?

For example by either calling seperate template files based on
presented languages (iterating over e.g. de_AT, de, with a fallback to
en, stat'ing template.$lang.html in turn) or calling a single template
but provide language selection features within that (though my
attribute checker template code is pretty much write-only as it is).

(I only care about accept-language and the attribute checker template
at this time, as I provide the complete error message text myself,
contrary to, say, sessionError where the error text will come from the
software. I'm not asking for those error messages to be translated).
-peter