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Twitter Emoji (Twemoji) Build Status

A simple library that provides standard Unicode emoji support across all platforms.

Unicode 8.0 and Diversity

The twemoji V2 adheres to the 8.0 Unicode version and supports 1661 different emoji, including diversity. The previous twemoji V1 adheres to the 7.0 Unicode version and supports 872 different emoji.

Version 2 CDN Support

The folks over at MaxCDN graciously provide CDN support for both version 1 and version 2.

For the latter one, use the following in the <head> tag of your HTML document(s):

<script src="//twemoji.maxcdn.com/2/twemoji.min.js"></script>

Breaking changes in V2

TL;DR: there's no variant anymore, all callbacks receives the transformed iconId and in some case the rawText too.

There are few potentially breaking changes in twemoji version 2:

  • the parse invoked function signature is now (iconId, options) instead of (icon, options, variant)
  • the attributes function will receives (rawText, iconId) instead of (icon, variant)
  • the default remote protocol is now https regardless the current site is http or even file
  • the default PNG icon size is 72 pixels and there are no other PNG assets for 16 or 32.
  • in order to access latest Unicode 8 ready assets you need to specify folder 2/72x72 or 2/svg.

Everything else is pretty much the same so if you were using defaults, all you need to do is to add the version 2/ before the twmoji.js file you were using.

Version 1 CDN Support

The folks over at MaxCDN graciously provide CDN support.

Just use the following in the <head> tag of your HTML document(s):

<script src="//twemoji.maxcdn.com/twemoji.min.js"></script>

Alternatively you can use cdnjs if you prefer:

<script src="//cdnjs.cloudflare.com/ajax/libs/twemoji/1.3.2/twemoji.min.js"></script>

API

Following all methods exposed through the twemoji namespace.

twemoji.parse( ... ) V1

This is the main parsing utility and has 3 overloads per each parsing type.

There are mainly two kind of parsing: string parsing and DOM parsing.

Each of them accept a callback to generate each image source or an options object with parsing info.

Here is a walk through all parsing possibilities:

string parsing (V1)

Given a generic string, it will replace all emoji with an <img> tag.

While this can be used to inject via innerHTML emoji image tags, please note that this method does not sanitize the string or prevent malicious code from being executed. As an example, if the text contains a <script> tag, this will not be converted into &lt;script&gt; since it's out of this method scope to prevent these kind of attacks.

However, for already sanitized strings, this method can be considered safe enough. Please see DOM parsing if security is one of your major concerns.

twemoji.parse('I \u2764\uFE0F emoji!');

// will produce
/*
I <img
  class="emoji"
  draggable="false"
  alt="❤️"
  src="https://twemoji.maxcdn.com/36x36/2764.png"> emoji!
*/

string parsing + callback If a callback is passed, the src attribute will be the one returned by the same callback.

twemoji.parse(
  'I \u2764\uFE0F emoji!',
  function(icon, options, variant) {
    return '/assets/' + options.size + '/' + icon + '.gif';
  }
);

// will produce
/*
I <img
  class="emoji"
  draggable="false"
  alt="❤️"
  src="/assets/36x36/2764.gif"> emoji!
*/

By default, the options.size parameter will be the string "36x36" and the variant will be an optional \uFE0F char that is usually ignored by default. If your assets include or distinguish between \u2764\uFE0F and \u2764, you might want to use such a variable.

string parsing + callback returning falsy If the callback returns "falsy values" such null, undefined, 0, false, or an empty string, nothing will change for that specific emoji.

var i = 0;
twemoji.parse(
  'emoji, m\u2764\uFE0Fn am\u2764\uFE0Fur',
  function(icon, options, variant) {
    if (i++ === 0) {
      return; // no changes made first call
    }
    return '/assets/' + icon + options.ext;
  }
);

// will produce
/*
emoji, m❤️n am<img
  class="emoji"
  draggable="false"
  alt="❤️"
  src="/assets/2764.png">ur
*/

string parsing + object In case an object is passed as second parameter, the passed options object will reflect its properties.

twemoji.parse(
  'I \u2764\uFE0F emoji!',
  {
    callback: function(icon, options) {
      return '/assets/' + options.size + '/' + icon + '.gif';
    },
    size: 128
  }
);

// will produce
/*
I <img
  class="emoji"
  draggable="false"
  alt="❤️"
  src="/assets/128x128/2764.gif"> emoji!
*/
DOM parsing

Differently from string parsing, if the first argument is a HTMLElement generated image tags will replace emoji that are inside #text node only without compromising surrounding nodes or listeners, and avoiding completely the usage of innerHTML.

If security is a major concern, this parsing can be considered the safest option but with a slightly penalized performance gap due to DOM operations that are inevitably costly compared to basic strings.

var div = document.createElement('div');
div.textContent = 'I \u2764\uFE0F emoji!';
document.body.appendChild(div);

twemoji.parse(document.body);

var img = div.querySelector('img');

// note the div is preserved
img.parentNode === div; // true

img.src;        // https://twemoji.maxcdn.com/36x36/2764.png
img.alt;        // \u2764\uFE0F
img.className;  // emoji
img.draggable;  // false

All other overloads described for string are available exactly same way for DOM parsing.

Object as parameter

Here the list of properties accepted by the optional object that could be passed to parse.

  {
    callback: Function,   // default the common replacer
    attributes: Function, // default returns {}
    base: string,         // default MaxCDN
    ext: string,          // default ".png"
    className: string,    // default "emoji"
    size: string|number,  // default "36x36"
    folder: string        // in case it's specified
                          // it replaces .size info, if any
  }
callback

The function to invoke in order to generate images src.

By default it is a function like the following one:

function imageSourceGenerator(icon, options) {
  return ''.concat(
    options.base, // by default Twitter Inc. CDN
    options.size, // by default "36x36" string
    '/',
    icon,         // the found emoji as code point
    options.ext   // by default ".png"
  );
}
attributes (V1)

The function to invoke in order to generate additional, custom attributes for the image tag.

By default it is a function like the following one:

function attributesCallback(icon, variant) {
  return {
    title: 'Emoji: ' + icon + variant
  };
}

Event handlers cannot be specified via this method, and twemoji-provided attributes (src, alt, className, draggable) cannot be re-defined.

base

The default url is the same as twemoji.base, so if you modify the former, it will reflect as default for all parsed strings or nodes.

ext

The default image extension is the same as twemoji.ext which is ".png".

If you modify the former, it will reflect as default for all parsed strings or nodes.

className

The default class per each generated image is emoji. It is possible to specify a different one through this property.

size

The default assets size is the same as twemoji.size which is "36x36".

If you modify the former, it will reflect as default for all parsed strings or nodes.

folder

In case there is no need to specify a size. It is possible to chose a folder, as is the case of SVG emoji.

twemoji.parse(genericNode, {
  folder: 'svg',
  ext: '.svg'
});

This will generate urls such https://twemoji.maxcdn.com/svg/2764.svg instead of using a specific size based one.

Utilities

Basic utilities / helpers to convert code points to JavaScript surrogates and vice versa.

twemoji.convert.fromCodePoint()

For given an HEX codepoint, returns UTF16 surrogate pairs.

twemoji.convert.fromCodePoint('1f1e8');
 // "\ud83c\udde8"

twemoji.convert.toCodePoint()

For given UTF16 surrogate pairs, returns the equivalent HEX codepoint.

 twemoji.convert.toCodePoint('\ud83c\udde8\ud83c\uddf3');
 // "1f1e8-1f1f3"
 
 twemoji.convert.toCodePoint('\ud83c\udde8\ud83c\uddf3', '~');
 // "1f1e8~1f1f3"

Tips

Inline Styles

If you'd like to size the emoji according to the surrounding text, you can add the following CSS to your stylesheet:

img.emoji {
   height: 1em;
   width: 1em;
   margin: 0 .05em 0 .1em;
   vertical-align: -0.1em;
}

This will make sure emoji derive their width and height from the font-size of the text they're shown with. It also adds just a little bit of space before and after each emoji, and pulls them upwards a little bit for better optical alignment.

UTF-8 Character Set

To properly support emoji, the document character must be set to UTF-8. This can done by including the following meta tag in the document <head>

<meta charset="utf-8">

Exclude Characters (V1)

To exclude certain characters from being replaced by twemoji.js, call twemoji.parse() with a callback, returning false for the specific unicode icon. For example:

twemoji.parse(document.body, {
    callback: function(icon, options, variant) {
        switch ( icon ) {
            case 'a9':      // © copyright
            case 'ae':      // ® registered trademark
            case '2122':    // ™ trademark
                return false;
        }
        return ''.concat(options.base, options.size, '/', icon, options.ext);
    }
});

Build

If you'd like to test and/or contribute please follow these instructions.

# clone this repo
git clone https://github.com/twitter/twemoji.git
cd twemoji

# install dependencies
npm install

# generate 2/twemoji*.js files
./2/utils/generate

If you'd like to test and/or propose some change to the V2 library please change ./2/utils/generate file at its end so that everything will be generated properly once launched.

Attribution Requirements

As an open source project, attribution is critical from a legal, practical and motivational perspective in our opinion. The graphics are licensed under the CC-BY 4.0 which has a pretty good guide on best practices for attribution.

However, we consider the guide a bit onerous and as a project, will accept a mention in a project README or an 'About' section or footer on a website. In mobile applications, a common place would be in the Settings/About section (for example, see the mobile Twitter application Settings->About->Legal section). We would consider a mention in the HTML/JS source sufficient also.

Community Projects

Committers and Contributors

  • Andrea Giammarchi (ex-Twitter)
  • Tom Wuttke (Twitter)
  • Joen Asmussen (WordPress)
  • Marcus Kazmierczak (WordPress)

The goal of this project is to simply provide emoji for everyone. We definitely welcome improvements and fixes, but we may not merge every pull request suggested by the community due to the simple nature of the project.

The rules for contributing are available at CONTRIBUTING.md file.

Thank you to all of our contributors.

License

Copyright 2014 Twitter, Inc and other contributors

Code licensed under the MIT License: http://opensource.org/licenses/MIT

Graphics licensed under CC-BY 4.0: https://creativecommons.org/licenses/by/4.0/