How do you know what encoding the user is inputing into the browser?

Question

I read Joel\'s article about character sets and so I\'m taking his advice to use UTF-8 on my web page and in my database. What I can\'t understand is what to do with user input

Answer 1

If your web-page using UTF-8, browser will convert to UTF-8 for you. So, even the special characters are in ASCII it will submit as UTF-8.

However, you never know itchy hand from an user that switch back the page encoding to ISO-8859-*.

You can make use on mb_detect_encoding, but is not 100% bullet-proof.

/* Detect character encoding with current detect_order */
echo mb_detect_encoding($str);

/* "auto" is expanded to "ASCII,JIS,UTF-8,EUC-JP,SJIS" */
echo mb_detect_encoding($str, "auto");

/* Specify encoding_list character encoding by comma separated list */
echo mb_detect_encoding($str, "JIS, eucjp-win, sjis-win");

/* Use array to specify encoding_list  */
$ary[] = "ASCII";
$ary[] = "JIS";
$ary[] = "EUC-JP";
echo mb_detect_encoding($str, $ary);