Limiting a textarea to a fixed number of chinese characters

I had been given a requirement from client saying limit the textarea – 200 characters in English, it is approximate 66 Chinese characters for UTF8.

I wonder how do I check them whether it i开发者_C百科s chinese character or english character and calculating them in the sense of maximum length ?

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Alright so I found a way (UTF-8 based) and somehow useful for me. But when I thought of client side, it was somehow still "yucks" ever since they are still able to edit it when inspect the dom element.....

Please advice me. Thanks

Code: My textarea and count box:

<textarea class="message" name="quiz_answer" cols="30" rows="4"></textarea><br />

<span class="countdown"></span>

Jquery document ready:

updateCountdown();

$('.message').attr('maxLength','25');

$('.message').keyup(updateCountdown);

updateCountdown function():

var previous = '';
var current = '';


//Count textarea words

function updateCountdown() {



var countMe = $(".message").val();

if(previous==''){
            previous = countMe;
            current = countMe;
}else{
            current = countMe;
}


    var escapedStr = encodeURI(countMe);

    if (escapedStr.indexOf("%") != -1) {

        var count = escapedStr.split("%").length - 1;

        if (count == 0) count++  //perverse case; can't happen with real UTF-8

        var tmp = escapedStr.length - (count * 3);

        count = count + tmp;

    } else {

        count = escapedStr.length;

    }



// 200 is the max message length

var remaining = 200 - count;



$('.countdown').text(remaining + ' characters remaining.');



if(remaining < 0){
            $(".message").val(previous);

}else{
           previous = current;

}

}