[Typo3-dev] character conversion JS -> PHP and class.t3lib_cs.php

[Rainer (Rene) Suthoelder]

hi!
perhaps someone can point me to the right direction:

i run across the problem of converting/manipulating strings from BE form 
fields.

the problem:
i want to import FE users from file, which is already running fine.
as a last step, i wanted to mimik the field eval functions: to get compliant 
usernames, they have to be all lowercase. not a big problem, i thought, but 
then i learned that this conversion is done on the client side using 
javascript (jsfunc.evalfield.js, toLowerCase()) which takes into account the 
remote's machine locale.

since i do my char conversion on the server side, problems occur with 
character sets: the file gets uploaded from whereever in whatever language 
and on the server we have the server's locale and that might differ from the 
browser's locale.

as a user you would expect (once told so) that you simply have to type in 
the password all lowercase. a german user would type in ö  (ö) instead 
of Ö (Ö). this only works if you have identical locales defined on both 
sides, otherwise you might get unpredicted strings.

so, what to do? should i simply use mb_strtolower() while converting? or how 
could class.t3lib_cs.php help me in that respect?

any help highly appreciated.

rainer