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Andrea Giammarchi d53dd8892b using xhtml friendly syntax as suggested in #236

2017-07-20 10:34:28 +02:00

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Twitter Emoji (Twemoji)

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

Twemoji v2.3 adheres to the Unicode 10.0 draft spec and supports the Emoji 5.0 draft spec

The Twemoji library offers support for 2,661 emojis, including skin tone and gender modifiers.

Please note

The files in the root folder in this project are deprecated and listed for CDN and historical reasons.

Please use the files for the current version (2) instead, located under the folder ./2/.

CDN Support

The folks over at MaxCDN have graciously provided CDN support.

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

<script src="//twemoji.maxcdn.com/2/twemoji.min.js?2.3.0"></script>

Breaking changes in V2

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

There are a 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 now receives (rawText, iconId) instead of (icon, variant)
the default remote protocol is now https regardless of whether 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 assets you need to specify folder 2/72x72 or 2/svg.

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

API

Following are all the methods exposed in the twemoji namespace.

twemoji.parse( ... ) V1

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

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

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

Here is a walkthrough of all parsing possibilities:

string parsing (V1)

Given a generic string, replaces all emoji with an <img> tag.

While this can be used to inject emoji via image tags in innerHTML, 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, it will not be converted into <script> since it's out of this method's 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 value of the src attribute will be the value returned by the 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 as 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

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

If security is a major concern, this parsing can be considered the safest option but with a slight performance penalty due to DOM operations that are inevitably costly.

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 in exactly the same way for DOM parsing.

Object as parameter

Here's the list of properties accepted by the optional object that can be passed to the parse function.

  {
    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 image src(s).

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 for each generated image is emoji. It is possible to specify a different one through this property.

size

The default asset 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 you don't want to specify a size for the image. It is possible to choose a folder, as in 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 image.

Utilities

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

twemoji.convert.fromCodePoint()

For a given HEX codepoint, returns UTF-16 surrogate pairs.

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

twemoji.convert.toCodePoint()

For given UTF-16 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 set 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 changes to the V2 library please change the ./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

Twemoji Awesome by @ellekasai: Use Twemoji using CSS classes (like Font Awesome).
Twemoji Ruby by @JollyGoodCode: Use Twemoji in Ruby.
Twemoji for Pencil by @Nathanielnw: Use Twemoji in Pencil.
FrwTwemoji - Twemoji in dotnet by @FrenchW: Use Twemoji in any dotnet project (C#, asp.net ...).
Emojiawesome - Twemoji for Yellow by @datenstrom: Use Twemoji in Yellow CMS.
EmojiPanel for Twitter by @danielbovey: Insert Twemoji into your tweets on twitter.com.
Twitter Color Emoji font by @bderickson: Use Twemoji as your system default font on Linux & OS X.
Emojica by @xoudini: An iOS framework allowing you to replace all standard emoji in strings with Twemoji.

Committers and Contributors

Bryan Haggerty (Twitter)
Tom Wuttke (ex-Twitter)
Andrea Giammarchi (ex-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 in the CONTRIBUTING.md file.

Thank you to all of our contributors.

License

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/

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