2008-10-08 15 views

Respuesta

39

Me tomé el tiempo para crear el punycode a continuación. Está basado en el código C en RFC 3492. Para usarlo con nombres de dominio, debe eliminar/agregar xn-- de/a la entrada/salida a/desde decodificar/codificar.

El utf16-class es necesario para convertir de la representación de caracteres internos de JavaScripts a Unicode y viceversa.

También existen funciones ToASCII y ToUnicode para facilitar la conversión entre IDN puny-codificado y ASCII.

//Javascript Punycode converter derived from example in RFC3492. 
//This implementation is created by [email protected] and released into public domain 
var punycode = new function Punycode() { 
    // This object converts to and from puny-code used in IDN 
    // 
    // punycode.ToASCII (domain) 
    // 
    // Returns a puny coded representation of "domain". 
    // It only converts the part of the domain name that 
    // has non ASCII characters. I.e. it dosent matter if 
    // you call it with a domain that already is in ASCII. 
    // 
    // punycode.ToUnicode (domain) 
    // 
    // Converts a puny-coded domain name to unicode. 
    // It only converts the puny-coded parts of the domain name. 
    // I.e. it dosent matter if you call it on a string 
    // that already has been converted to unicode. 
    // 
    // 
    this.utf16 = { 
     // The utf16-class is necessary to convert from javascripts internal character representation to unicode and back. 
     decode:function(input){ 
      var output = [], i=0, len=input.length,value,extra; 
      while (i < len) { 
       value = input.charCodeAt(i++); 
       if ((value & 0xF800) === 0xD800) { 
        extra = input.charCodeAt(i++); 
        if (((value & 0xFC00) !== 0xD800) || ((extra & 0xFC00) !== 0xDC00)) { 
         throw new RangeError("UTF-16(decode): Illegal UTF-16 sequence"); 
        } 
        value = ((value & 0x3FF) << 10) + (extra & 0x3FF) + 0x10000; 
       } 
       output.push(value); 
      } 
      return output; 
     }, 
     encode:function(input){ 
      var output = [], i=0, len=input.length,value; 
      while (i < len) { 
       value = input[i++]; 
       if ((value & 0xF800) === 0xD800) { 
        throw new RangeError("UTF-16(encode): Illegal UTF-16 value"); 
       } 
       if (value > 0xFFFF) { 
        value -= 0x10000; 
        output.push(String.fromCharCode(((value >>>10) & 0x3FF) | 0xD800)); 
        value = 0xDC00 | (value & 0x3FF); 
       } 
       output.push(String.fromCharCode(value)); 
      } 
      return output.join(""); 
     } 
    } 

    //Default parameters 
    var initial_n = 0x80; 
    var initial_bias = 72; 
    var delimiter = "\x2D"; 
    var base = 36; 
    var damp = 700; 
    var tmin=1; 
    var tmax=26; 
    var skew=38; 
    var maxint = 0x7FFFFFFF; 

    // decode_digit(cp) returns the numeric value of a basic code 
    // point (for use in representing integers) in the range 0 to 
    // base-1, or base if cp is does not represent a value. 

    function decode_digit(cp) { 
     return cp - 48 < 10 ? cp - 22 : cp - 65 < 26 ? cp - 65 : cp - 97 < 26 ? cp - 97 : base; 
    } 

    // encode_digit(d,flag) returns the basic code point whose value 
    // (when used for representing integers) is d, which needs to be in 
    // the range 0 to base-1. The lowercase form is used unless flag is 
    // nonzero, in which case the uppercase form is used. The behavior 
    // is undefined if flag is nonzero and digit d has no uppercase form. 

    function encode_digit(d, flag) { 
     return d + 22 + 75 * (d < 26) - ((flag != 0) << 5); 
     // 0..25 map to ASCII a..z or A..Z 
     // 26..35 map to ASCII 0..9 
    } 
    //** Bias adaptation function ** 
    function adapt(delta, numpoints, firsttime) { 
     var k; 
     delta = firsttime ? Math.floor(delta/damp) : (delta >> 1); 
     delta += Math.floor(delta/numpoints); 

     for (k = 0; delta > (((base - tmin) * tmax) >> 1); k += base) { 
       delta = Math.floor(delta/(base - tmin)); 
     } 
     return Math.floor(k + (base - tmin + 1) * delta/(delta + skew)); 
    } 

    // encode_basic(bcp,flag) forces a basic code point to lowercase if flag is zero, 
    // uppercase if flag is nonzero, and returns the resulting code point. 
    // The code point is unchanged if it is caseless. 
    // The behavior is undefined if bcp is not a basic code point. 

    function encode_basic(bcp, flag) { 
     bcp -= (bcp - 97 < 26) << 5; 
     return bcp + ((!flag && (bcp - 65 < 26)) << 5); 
    } 

    // Main decode 
    this.decode=function(input,preserveCase) { 
     // Dont use utf16 
     var output=[]; 
     var case_flags=[]; 
     var input_length = input.length; 

     var n, out, i, bias, basic, j, ic, oldi, w, k, digit, t, len; 

     // Initialize the state: 

     n = initial_n; 
     i = 0; 
     bias = initial_bias; 

     // Handle the basic code points: Let basic be the number of input code 
     // points before the last delimiter, or 0 if there is none, then 
     // copy the first basic code points to the output. 

     basic = input.lastIndexOf(delimiter); 
     if (basic < 0) basic = 0; 

     for (j = 0; j < basic; ++j) { 
      if(preserveCase) case_flags[output.length] = (input.charCodeAt(j) -65 < 26); 
      if (input.charCodeAt(j) >= 0x80) { 
       throw new RangeError("Illegal input >= 0x80"); 
      } 
      output.push(input.charCodeAt(j)); 
     } 

     // Main decoding loop: Start just after the last delimiter if any 
     // basic code points were copied; start at the beginning otherwise. 

     for (ic = basic > 0 ? basic + 1 : 0; ic < input_length;) { 

      // ic is the index of the next character to be consumed, 

      // Decode a generalized variable-length integer into delta, 
      // which gets added to i. The overflow checking is easier 
      // if we increase i as we go, then subtract off its starting 
      // value at the end to obtain delta. 
      for (oldi = i, w = 1, k = base; ; k += base) { 
        if (ic >= input_length) { 
         throw RangeError ("punycode_bad_input(1)"); 
        } 
        digit = decode_digit(input.charCodeAt(ic++)); 

        if (digit >= base) { 
         throw RangeError("punycode_bad_input(2)"); 
        } 
        if (digit > Math.floor((maxint - i)/w)) { 
         throw RangeError ("punycode_overflow(1)"); 
        } 
        i += digit * w; 
        t = k <= bias ? tmin : k >= bias + tmax ? tmax : k - bias; 
        if (digit < t) { break; } 
        if (w > Math.floor(maxint/(base - t))) { 
         throw RangeError("punycode_overflow(2)"); 
        } 
        w *= (base - t); 
      } 

      out = output.length + 1; 
      bias = adapt(i - oldi, out, oldi === 0); 

      // i was supposed to wrap around from out to 0, 
      // incrementing n each time, so we'll fix that now: 
      if (Math.floor(i/out) > maxint - n) { 
       throw RangeError("punycode_overflow(3)"); 
      } 
      n += Math.floor(i/out) ; 
      i %= out; 

      // Insert n at position i of the output: 
      // Case of last character determines uppercase flag: 
      if (preserveCase) { case_flags.splice(i, 0, input.charCodeAt(ic -1) -65 < 26);} 

      output.splice(i, 0, n); 
      i++; 
     } 
     if (preserveCase) { 
      for (i = 0, len = output.length; i < len; i++) { 
       if (case_flags[i]) { 
        output[i] = (String.fromCharCode(output[i]).toUpperCase()).charCodeAt(0); 
       } 
      } 
     } 
     return this.utf16.encode(output); 
    }; 

    //** Main encode function ** 

    this.encode = function (input,preserveCase) { 
     //** Bias adaptation function ** 

     var n, delta, h, b, bias, j, m, q, k, t, ijv, case_flags; 

     if (preserveCase) { 
      // Preserve case, step1 of 2: Get a list of the unaltered string 
      case_flags = this.utf16.decode(input); 
     } 
     // Converts the input in UTF-16 to Unicode 
     input = this.utf16.decode(input.toLowerCase()); 

     var input_length = input.length; // Cache the length 

     if (preserveCase) { 
      // Preserve case, step2 of 2: Modify the list to true/false 
      for (j=0; j < input_length; j++) { 
       case_flags[j] = input[j] != case_flags[j]; 
      } 
     } 

     var output=[]; 


     // Initialize the state: 
     n = initial_n; 
     delta = 0; 
     bias = initial_bias; 

     // Handle the basic code points: 
     for (j = 0; j < input_length; ++j) { 
      if (input[j] < 0x80) { 
       output.push(
        String.fromCharCode(
         case_flags ? encode_basic(input[j], case_flags[j]) : input[j] 
        ) 
       ); 
      } 
     } 

     h = b = output.length; 

     // h is the number of code points that have been handled, b is the 
     // number of basic code points 

     if (b > 0) output.push(delimiter); 

     // Main encoding loop: 
     // 
     while (h < input_length) { 
      // All non-basic code points < n have been 
      // handled already. Find the next larger one: 

      for (m = maxint, j = 0; j < input_length; ++j) { 
       ijv = input[j]; 
       if (ijv >= n && ijv < m) m = ijv; 
      } 

      // Increase delta enough to advance the decoder's 
      // <n,i> state to <m,0>, but guard against overflow: 

      if (m - n > Math.floor((maxint - delta)/(h + 1))) { 
       throw RangeError("punycode_overflow (1)"); 
      } 
      delta += (m - n) * (h + 1); 
      n = m; 

      for (j = 0; j < input_length; ++j) { 
       ijv = input[j]; 

       if (ijv < n) { 
        if (++delta > maxint) return Error("punycode_overflow(2)"); 
       } 

       if (ijv == n) { 
        // Represent delta as a generalized variable-length integer: 
        for (q = delta, k = base; ; k += base) { 
         t = k <= bias ? tmin : k >= bias + tmax ? tmax : k - bias; 
         if (q < t) break; 
         output.push(String.fromCharCode(encode_digit(t + (q - t) % (base - t), 0))); 
         q = Math.floor((q - t)/(base - t)); 
        } 
        output.push(String.fromCharCode(encode_digit(q, preserveCase && case_flags[j] ? 1:0))); 
        bias = adapt(delta, h + 1, h == b); 
        delta = 0; 
        ++h; 
       } 
      } 

      ++delta, ++n; 
     } 
     return output.join(""); 
    } 

    this.ToASCII = function (domain) { 
     var domain_array = domain.split("."); 
     var out = []; 
     for (var i=0; i < domain_array.length; ++i) { 
      var s = domain_array[i]; 
      out.push(
       s.match(/[^A-Za-z0-9-]/) ? 
       "xn--" + punycode.encode(s) : 
       s 
      ); 
     } 
     return out.join("."); 
    } 
    this.ToUnicode = function (domain) { 
     var domain_array = domain.split("."); 
     var out = []; 
     for (var i=0; i < domain_array.length; ++i) { 
      var s = domain_array[i]; 
      out.push(
       s.match(/^xn--/) ? 
       punycode.decode(s.slice(4)) : 
       s 
      ); 
     } 
     return out.join("."); 
    } 
}(); 

Actualizar licencia:
De RFC3492:

exención de responsabilidad y licencia

En cuanto a todo este documento o cualquier parte del mismo (incluyendo el pseudocódigo y el código C), el autor no hace garantías y no es responsable por ningún daño resultante de su uso. El autor concede un permiso irrevocable a cualquier persona para usarlo, modificarlo y distribuirlo de cualquier manera que no disminuya los derechos de cualquier otra persona para usarlo, modificarlo y distribuirlo, siempre que las obras derivadas redistribuidas no contengan información engañosa del autor o de la versión. Los trabajos derivados no necesitan ser licenciados bajo términos similares.

Puse mi trabajo en este punycode y utf16 en el dominio público. Sería bueno recibir un correo electrónico diciéndome en qué proyecto lo usa.

+0

los usuarios no pueden enviarte un correo electrónico cuando no proporciones una dirección de correo electrónico válida en el perfil de tu página de usuario. La tradición es ponerlo en el campo "sobre mí" –

+0

@Jeff: cuando escribí eso pensé ya estaba allí. Fijo. – some

+1

¡Impresionante trabajo, _some_! Esta es una de las implementaciones de Punycode que comparé mientras escribía [my own] (http://stackoverflow.com/questions/183485/can-anyone-recommend-a-good-free-javascript-for-punycode-to-unicode -conversion/8110556 # 8110556). Espero que no te moleste que reutilice tu clase UTF16 :) –

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