Replacing emojis with html entities

This week I came across a case where using an emoji in my code broke a page I was working on (I suspected the emoji was causing an error in the database which stopped the rest of the page from rendering). Therefore I wanted to share a way that you can replace any emoji in a string with the HTML entity equivelent which works flawlessly. This post is only going to be a short one since I don't want to deep dive into unicode and the pros and cons of such a format but make rather give you a solution can use in such a situation.

Lets jump in...

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let emojiUnicode = (input) => {
  return emojiUnicode.raw(input).toString('16');
};
emojiUnicode.raw = function (input) {
  if (input.length === 1) {
    return input.charCodeAt(0);
  }
  let comp =
    (input.charCodeAt(0) - 0xd800) * 0x400 +
    (input.charCodeAt(1) - 0xdc00) +
    0x10000;
  if (comp < 0) {
    return input.charCodeAt(0);
  }
  return comp;
};

So above is a function to convert any emoji passed in as an argument to a unicode string, taken from the emoji-unicode npm package (thanks to ionicabizau for creating the package)

But now we need to find a way to grab all of the emojis in a string, pass them into the function and replace each emoji with the HTML entity.

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export const convertEmojis = (string) => {
  var regex = /(?:[\u2700-\u27bf]|(?:\ud83c[\udde6-\uddff]){2}|[\ud800-\udbff][\udc00-\udfff]|[\u0023-\u0039]\ufe0f?\u20e3|\u3299|\u3297|\u303d|\u3030|\u24c2|\ud83c[\udd70-\udd71]|\ud83c[\udd7e-\udd7f]|\ud83c\udd8e|\ud83c[\udd91-\udd9a]|\ud83c[\udde6-\uddff]|[\ud83c[\ude01\uddff]|\ud83c[\ude01-\ude02]|\ud83c\ude1a|\ud83c\ude2f|[\ud83c[\ude32\ude02]|\ud83c\ude1a|\ud83c\ude2f|\ud83c[\ude32-\ude3a]|[\ud83c[\ude50\ude3a]|\ud83c[\ude50-\ude51]|\u203c|\u2049|[\u25aa-\u25ab]|\u25b6|\u25c0|[\u25fb-\u25fe]|\u00a9|\u00ae|\u2122|\u2139|\ud83c\udc04|[\u2600-\u26FF]|\u2b05|\u2b06|\u2b07|\u2b1b|\u2b1c|\u2b50|\u2b55|\u231a|\u231b|\u2328|\u23cf|[\u23e9-\u23f3]|[\u23f8-\u23fa]|\ud83c\udccf|\u2934|\u2935|[\u2190-\u21ff])/g;
  let emojis = string.match(regex);
  if (emojis) {
    let convertedEmojis = emojis.map((e) => {
      return emojiUnicode(e);
    });
    let index = 0;
    return string.replace(regex, function () {
      let unicodeEmoji = `&#x${convertedEmojis[index]};`;
      index++;
      return `${unicodeEmoji}`;
    });
  }
  return string;
};

First of all we create a regex to find all of the emojis in the string, taken from Kevin Scott's great post emojis in javascript. If we then get a match in the string we map through the returned array converting and returning each value as a unicode value. We then take our string and replace each emoji with the unicode value prepended with &#x and appended with a ; which turns our unicode string into a HTML entity. Note ; tells the browser that it is the end of the entity.

And that's it! Super simple but super effective in coverting your emojis in a string.

Hope you enjoyed and let me know your thoughts