index.js

/**
 * Javascript Arabic Reshaper by Louy Alakkad
 * https://github.com/louy/Javascript-Arabic-Reshaper
 * Based on (http://git.io/vsnAd)
 */
(function(root, factory) {
  var name = 'ArabicReshaper';
  /* global define, module */
  /* istanbul ignore next */
  if (typeof define === 'function' && define.amd) {
    // AMD. Register as an anonymous module.
    define(factory);
  } else if (typeof module === 'object' && module.exports) {
    module.exports = factory();
  } else {
    // Browser globals
    root[name] = factory();
  }
}(this, function() {

  var charsMap = [
      /* code,isolated,initial, medial, final */
      [0x0621, 0xFE80,   null,   null,   null], /* HAMZA */
      [0x0622, 0xFE81,   null,   null, 0xFE82], /* ALEF_MADDA */
      [0x0623, 0xFE83,   null,   null, 0xFE84], /* ALEF_HAMZA_ABOVE */
      [0x0624, 0xFE85,   null,   null, 0xFE86], /* WAW_HAMZA */
      [0x0625, 0xFE87,   null,   null, 0xFE88], /* ALEF_HAMZA_BELOW */
      [0x0626, 0xFE89, 0xFE8B, 0xFE8C, 0xFE8A], /* YEH_HAMZA */
      [0x0627, 0xFE8D,   null,   null, 0xFE8E], /* ALEF */
      [0x0628, 0xFE8F, 0xFE91, 0xFE92, 0xFE90], /* BEH */
      [0x0629, 0xFE93,   null,   null, 0xFE94], /* TEH_MARBUTA */
      [0x062A, 0xFE95, 0xFE97, 0xFE98, 0xFE96], /* TEH */
      [0x062B, 0xFE99, 0xFE9B, 0xFE9C, 0xFE9A], /* THEH */
      [0x062C, 0xFE9D, 0xFE9F, 0xFEA0, 0xFE9E], /* JEEM */
      [0x062D, 0xFEA1, 0xFEA3, 0xFEA4, 0xFEA2], /* HAH */
      [0x062E, 0xFEA5, 0xFEA7, 0xFEA8, 0xFEA6], /* KHAH */
      [0x062F, 0xFEA9,   null,   null, 0xFEAA], /* DAL */
      [0x0630, 0xFEAB,   null,   null, 0xFEAC], /* THAL */
      [0x0631, 0xFEAD,   null,   null, 0xFEAE], /* REH */
      [0x0632, 0xFEAF,   null,   null, 0xFEB0], /* ZAIN */
      [0x0633, 0xFEB1, 0xFEB3, 0xFEB4, 0xFEB2], /* SEEN */
      [0x0634, 0xFEB5, 0xFEB7, 0xFEB8, 0xFEB6], /* SHEEN */
      [0x0635, 0xFEB9, 0xFEBB, 0xFEBC, 0xFEBA], /* SAD */
      [0x0636, 0xFEBD, 0xFEBF, 0xFEC0, 0xFEBE], /* DAD */
      [0x0637, 0xFEC1, 0xFEC3, 0xFEC4, 0xFEC2], /* TAH */
      [0x0638, 0xFEC5, 0xFEC7, 0xFEC8, 0xFEC6], /* ZAH */
      [0x0639, 0xFEC9, 0xFECB, 0xFECC, 0xFECA], /* AIN */
      [0x063A, 0xFECD, 0xFECF, 0xFED0, 0xFECE], /* GHAIN */
      [0x0640, 0x0640, 0x0640, 0x0640, 0x0640], /* TATWEEL */
      [0x0641, 0xFED1, 0xFED3, 0xFED4, 0xFED2], /* FEH */
      [0x0642, 0xFED5, 0xFED7, 0xFED8, 0xFED6], /* QAF */
      [0x0643, 0xFED9, 0xFEDB, 0xFEDC, 0xFEDA], /* KAF */
      [0x0644, 0xFEDD, 0xFEDF, 0xFEE0, 0xFEDE], /* LAM */
      [0x0645, 0xFEE1, 0xFEE3, 0xFEE4, 0xFEE2], /* MEEM */
      [0x0646, 0xFEE5, 0xFEE7, 0xFEE8, 0xFEE6], /* NOON */
      [0x0647, 0xFEE9, 0xFEEB, 0xFEEC, 0xFEEA], /* HEH */
      [0x0648, 0xFEED,   null,   null, 0xFEEE], /* WAW */
      [0x0649, 0xFEEF,   null,   null, 0xFEF0], /* ALEF_MAKSURA */
      [0x064A, 0xFEF1, 0xFEF3, 0xFEF4, 0xFEF2], /* YEH */
      [0x067E, 0xFB56, 0xFB58, 0xFB59, 0xFB57], /* PEH */
      [0x06CC, 0xFBFC, 0xFBFE, 0xFBFF, 0xFBFD], /* Farsi Yeh */
      [0x0686, 0xFB7A, 0xFB7C, 0xFB7D, 0xFB7B], /* Tcheh */
      [0x06A9, 0xFB8E, 0xFB90, 0xFB91, 0xFB8F], /* Keheh */
      [0x06AF, 0xFB92, 0xFB94, 0xFB95, 0xFB93], /* Gaf */
      [0x0698, 0xFB8A,   null,   null, 0xFB8B], /* Jeh */
    ],
    combCharsMap = [
      [[0x0644, 0x0622], 0xFEF5, null, null, 0xFEF6], /* LAM_ALEF_MADDA */
      [[0x0644, 0x0623], 0xFEF7, null, null, 0xFEF8], /* LAM_ALEF_HAMZA_ABOVE */
      [[0x0644, 0x0625], 0xFEF9, null, null, 0xFEFA], /* LAM_ALEF_HAMZA_BELOW */
      [[0x0644, 0x0627], 0xFEFB, null, null, 0xFEFC], /* LAM_ALEF */
    ],
    transChars = [
      0x0610, /* ARABIC SIGN SALLALLAHOU ALAYHE WASSALLAM */
      0x0612, /* ARABIC SIGN ALAYHE ASSALLAM */
      0x0613, /* ARABIC SIGN RADI ALLAHOU ANHU */
      0x0614, /* ARABIC SIGN TAKHALLUS */
      0x0615, /* ARABIC SMALL HIGH TAH */
      0x064B, /* ARABIC FATHATAN */
      0x064C, /* ARABIC DAMMATAN */
      0x064D, /* ARABIC KASRATAN */
      0x064E, /* ARABIC FATHA */
      0x064F, /* ARABIC DAMMA */
      0x0650, /* ARABIC KASRA */
      0x0651, /* ARABIC SHADDA */
      0x0652, /* ARABIC SUKUN */
      0x0653, /* ARABIC MADDAH ABOVE */
      0x0654, /* ARABIC HAMZA ABOVE */
      0x0655, /* ARABIC HAMZA BELOW */
      0x0656, /* ARABIC SUBSCRIPT ALEF */
      0x0657, /* ARABIC INVERTED DAMMA */
      0x0658, /* ARABIC MARK NOON GHUNNA */
      0x0670, /* ARABIC LETTER SUPERSCRIPT ALEF */
      0x06D6, /* ARABIC SMALL HIGH LIGATURE SAD WITH LAM WITH ALEF MAKSURA */
      0x06D7, /* ARABIC SMALL HIGH LIGATURE QAF WITH LAM WITH ALEF MAKSURA */
      0x06D8, /* ARABIC SMALL HIGH MEEM INITIAL FORM */
      0x06D9, /* ARABIC SMALL HIGH LAM ALEF */
      0x06DA, /* ARABIC SMALL HIGH JEEM */
      0x06DB, /* ARABIC SMALL HIGH THREE DOTS */
      0x06DC, /* ARABIC SMALL HIGH SEEN */
      0x06DF, /* ARABIC SMALL HIGH ROUNDED ZERO */
      0x06E0, /* ARABIC SMALL HIGH UPRIGHT RECTANGULAR ZERO */
      0x06E1, /* ARABIC SMALL HIGH DOTLESS HEAD OF KHAH */
      0x06E2, /* ARABIC SMALL HIGH MEEM ISOLATED FORM */
      0x06E3, /* ARABIC SMALL LOW SEEN */
      0x06E4, /* ARABIC SMALL HIGH MADDA */
      0x06E7, /* ARABIC SMALL HIGH YEH */
      0x06E8, /* ARABIC SMALL HIGH NOON */
      0x06EA, /* ARABIC EMPTY CENTRE LOW STOP */
      0x06EB, /* ARABIC EMPTY CENTRE HIGH STOP */
      0x06EC, /* ARABIC ROUNDED HIGH STOP WITH FILLED CENTRE */
      0x06ED, /* ARABIC SMALL LOW MEEM */
    ];

  function characterMapContains(c) {
    for (var i = 0; i < charsMap.length; ++i) {
      if (charsMap[ i ][0] === c) {
        return true;
      }
    }

    return false;
  }

  function getCharRep(c) {
    for (var i = 0; i < charsMap.length; ++i) {
      if (charsMap[ i ][0] === c) {
        return charsMap[i];
      }
    }

    return false;
  }

  function getCombCharRep(c1, c2) {
    for (var i = 0; i < combCharsMap.length; ++i) {
      if (combCharsMap[i][0][0] === c1 && combCharsMap[i][0][1] === c2) {
        return combCharsMap[i];
      }
    }

    // We should never reach here...
    // istanbul ignore next
    return false;
  }

  function isTransparent(c) {
    for (var i = 0; i < transChars.length; ++i) {
      if (transChars[i] === c) {
        return true;
      }
    }

    return false;
  }

  function getOriginalCharsFromCode(code) {
    var j;

    for (j = 0; j < charsMap.length; ++j) {
      if (charsMap[j].indexOf(code) > -1) {
        return String.fromCharCode(charsMap[j][0]);
      }
    }

    for (j = 0; j < combCharsMap.length; ++j) {
      if (combCharsMap[j].indexOf(code) > -1) {
        return String.fromCharCode(combCharsMap[j][0][0]) +
              String.fromCharCode(combCharsMap[j][0][1]);
      }
    }

    return String.fromCharCode(code);
  }

  return {
    convertArabic: function(normal, optUseOriginalInsteadOfIsolated) {
      var crep,
        combcrep,
        shaped = '';

      for (var i = 0; i < normal.length; ++i) {
        var current = normal.charCodeAt(i);
        if (characterMapContains(current)) {
          var prev = null,
              next = null,
              prevID = i - 1,
              nextID = i + 1;

          /*
           Transparent characters have no effect in the shaping process.
           So, ignore all the transparent characters that are BEFORE the
           current character.
           */
          for (; prevID >= 0; --prevID) {
            if (!isTransparent(normal.charCodeAt(prevID))) {
              break;
            }
          }

          prev = (prevID >= 0) ? normal.charCodeAt(prevID) : null;
          crep = prev ? getCharRep(prev) : false;
          if (!crep || crep[2] == null && crep[3] == null) {
            prev = null; // prev character doesn’t connect with its successor
          }

          /*
           Transparent characters have no effect in the shaping process.
           So, ignore all the transparent characters that are AFTER the
           current character.
           */
          for (; nextID < normal.length; ++nextID) {
            if (!isTransparent(normal.charCodeAt(nextID))) {
              break;
            }
          }

          next = (nextID < normal.length) ? normal.charCodeAt(nextID) : null;
          crep = next ? getCharRep(next) : false;
          if (!crep || crep[3] == null && crep[4] == null) {
            next = null; // next character doesn’t connect with its predecessor
          }

          /* Combinations */
          if (current === 0x0644 && next != null &&
            (next === 0x0622 || next === 0x0623 || next === 0x0625 || next === 0x0627)) {
            combcrep = getCombCharRep(current, next);
            if (prev != null) {
              shaped += String.fromCharCode(combcrep[4]);
            } else {
              shaped += String.fromCharCode(combcrep[1]);
            }

            ++i;
            continue;
          }

          crep = getCharRep(current);

          /* Medial */
          if (prev != null && next != null && crep[3] != null) {
            shaped += String.fromCharCode(crep[3]);
            continue;
          } else /* Final */
            if (prev != null && crep[4] != null) {
              shaped += String.fromCharCode(crep[4]);
              continue;
            } else /* Initial */
            if (next != null && crep[2] != null) {
              shaped += String.fromCharCode(crep[2]);
              continue;
            } else /* Isolated */ {
              // A lot of Arabic font files are missing glyphs in the isolated block
              // this allows the shaper to just use the original characters instead
              // which should not mess up the shaping process.
              shaped += optUseOriginalInsteadOfIsolated
                  ? String.fromCharCode(crep[0])
                  : String.fromCharCode(crep[1]);
            }
        } else {
          shaped += String.fromCharCode(current);
        }
      }

      return shaped;
    },

    // convert from Arabic Presentation Forms B
    convertArabicBack: function(apfb) {
      var toReturn = '',
          selectedChar;

      var i;

      theLoop:
      for (i = 0; i < apfb.length; ++i) {
        selectedChar = apfb.charCodeAt(i);

        toReturn += getOriginalCharsFromCode(selectedChar);
      }

      return toReturn;
    },
  };
}));