How to deny foreign alphabets in utf-8 in PHP 5.x (symfony)?

Question

I have to disable chinese, japanese, cyrillic (and so on) alphabets to be entered by users in my website, at validation time (only server side validation). At the same time I want all latin accented characters to be allowed. I use symfony 1.1 and PHP 5.2, using utf-8, of course. Any hint?

Answer 1

You can always convert to latin1 and then back again. That would discard any non latin1 characters. Eg.:

$str = utf8_encode(utf8_decode($str));

I wonder why you want this in the first place though?

Answer 2

BTW, if a user inserts something in our DB, I need it to be written in understandable alphabet by our team and by all of our customers, for a lot of reasons. Even if this would discourage users from other countries...

Answer 3

If you need to pick and choose, you won't be able to avoid using regex and/or creating a list of allowed characters.

Yes this is not easy nor quick, but if you want to nit-pick characters, you might need to get specific.