How to convert utf-8 string to urlencoded win1251 in javascript

Question

I have a string, for instance \"холодильник\" and looking for a way to convert it to url encoded win1251 string which is %F5%EE%EB%EE%E4%E8%EB%FC%ED%E8%EA

Answer 1

I have my own method. It's a little bit tricky but without a huge Array of charset table (assuming that your page is in "CP1251" encoding):

// "special" chars
var charEncodeCache = {
  ' ': '%20',
  '+': '%2B',
  '%': '%25',
  '&': '%26',
  '=': '%3D'
};

function encodeURIComponent1251(str) {
  if(!str) return str;

  var result = '';

  for(var i = 0; i < str.length; i++) {
    var char = str.charAt(i);
    if(typeof(charEncodeCache[char]) != 'undefined') {
      result += charEncodeCache[char];
    } else {
      var utfEncode = encodeURIComponent(char);
      if(utfEncode.charAt(0) == '%' && utfEncode.indexOf('%', 1) > -1) {
        /// it's two-byte UTF-char, we should convert it
        if(!this.__encode_anchor) this.__encode_anchor = document.createElement('a');
        this.__encode_anchor = "http://" + document.domain + "/encoded_str=?" + char;
        var encodedChar = this.__encode_anchor.href.split('encoded_str=?')[1];
        charEncodeCache[char] = encodedChar;
        result += encodedChar;
      } else {
        /// single byte char, just adding it to result
        result += char;
      }
    }
  }
  return result;
}

And it's a little bit faster than unicodeToWin1251_UrlEncoded ;-)

http://jsperf.com/encode-from-utf-to-cp1251

Not too much, but still faster and you'll have a great economy on the sources weight.