Turkish case conversion in JavaScript

Question

I want to convert strings to lower or upper case in JavaScript in the locale I wanted. I think standard functions like toUpperCase() and toLocaleUpperCase() do not satisfy this need. toLocale functions do not behave as they should.

For example, in Safari 4, Chrome 4 Beta, Firefox 3.5.x on my system it converts strings with Turkish characters incorrectly. The browsers respond to navigator.language as "en-US", "tr", "en-US" respectively. But there is no way to get user's Accept-Lang setting in the browser as far as I could found. Only Chrome gives me "tr" although I have configured every browser Turkish locale preferred. I think these settings only affect HTTP header, but we can't access to these settings via JavaScript.

In the Mozilla documentation it says

The characters within a string are converted to ... while respecting the current locale. For most languages, this will return the same as ...

I think it's valid for Turkish, it doesn't differ it's configured as en or tr. In Turkish it should convert "DİNÇ" to "dinç" and "DINÇ" to "dınç" or vice-versa.

Is there any JavaScript library that satisfies this need? I think it should not only converting correctly in user's locale, but also it should support conversion via a locale parameter. Because developers cannot access to user's configured preferred language.

user_7098452 · Answer

    var  a="lişliş lğüğpğp İŞİŞİŞ lşi ĞĞHFGH ÜGFHFHG ühüüüğ üğüğş ş ş Ş  İ i  ılk Ilk";

var s=a.split(' ');

var netice="";

s.forEach(function(g) {
  if (g.length>1)
    netice+=g[0].toLocaleUpperCase('tr')+
      g.slice(1).toLocaleLowerCase('tr')+" "; 
  else
    netice+=g.toLocaleUpperCase('tr')+" ";
});

alert(netice);

user_13056635 · Answer

String.prototype.turkishtoEnglish = function () {
    var temp = this.toUpperCase();
    temp = temp.replace('Ğ', 'g')
      .replace('G', 'g')
      .replace('Ü', 'u')
      .replace('Ş', 's')
      .replace('I', 'i')
      .replace('İ', 'i')
      .replace('Ö', 'o')
      .replace('Ç', 'c')
      return temp;
  };

That's it.

Turkish case conversion in JavaScript

6 Answers