Replace emoji characters in a string with an image of said emoji.

emojiToImage.js

//  (c) 2012 Mark Wunsch http://markwunsch.com
//  MIT license.

if (!String.fromCodePoint) {
    /*!
    * ES6 Unicode Shims 0.1
    * (c) 2012 Steven Levithan <http://slevithan.com/>
    * MIT License
    */
    String.fromCodePoint = function fromCodePoint () {
        var chars = [], point, offset, units, i;
        for (i = 0; i < arguments.length; ++i) {
            point = arguments[i];
            offset = point - 0x10000;
            units = point > 0xFFFF ? [0xD800 + (offset >> 10), 0xDC00 + (offset & 0x3FF)] : [point];
            chars.push(String.fromCharCode.apply(null, units));
        }
        return chars.join("");
    }
}

(function (root, factory) {
  if (typeof define === 'function' && define.amd) {
    define([], factory);
  } else {
    root.emoji = factory();
  }
}(this, function () {
  var emoji = {},
      EMOJI_HEX_TO_TUPLE;

  var EMOJI_HEX_TO_TUPLE = {
    "1f604" : ["http://www.emoji-cheat-sheet.com/graphics/emojis/smile.png", "smiling face with open mouth and smiling eyes"]
  }

  var hexToEmoji = emoji.hexToEmoji = function (hex) {
    var codepoint = parseInt(hex, 16);
    return String.fromCodePoint(codepoint);
  }

  function emojiPatterns (hex) {
    return new RegExp(hexToEmoji(hex), "g");
  }

  function imageTagFromTuple (tuple) {
      return '<img src="'+tuple[0]+'" alt="'+tuple[1]+'" style="width: 1em;" />';
  }

  emoji.imageReplace = function replaceEmojiWithImage (input) {
    var buffer = input,
        tuple;
    for (var hex in EMOJI_HEX_TO_TUPLE) {
      if (EMOJI_HEX_TO_TUPLE.hasOwnProperty(hex)) {
        tuple = EMOJI_HEX_TO_TUPLE[hex];
        buffer = buffer.replace(emojiPatterns(hex), imageTagFromTuple(tuple));
      }
    }
    return buffer;
  }

  return emoji;
}));