emoji-picker-element

A lightweight emoji picker, distributed as a custom element.

It's built on top of IndexedDB, so it consumes far less memory than other emoji pickers. It also uses Svelte, so it has a minimal runtime footprint.

Design goals:

• Store emoji data in IndexedDB, not memory
• Render native emoji, no spritesheets
• Accessible
• Drop-in as a vanilla web component

Install

npm install emoji-picker-element

Usage

<emoji-picker></emoji-picker>

import 'emoji-picker-element';

Then listen for emoji-click events:

const element = document.querySelector('emoji-picker');
element.addEventListener('emoji-click', event => console.log(event.detail))

This will log:

{
  "annotation": "grinning face",
  "group": 0,
  "order": 1,
  "shortcodes": [ "gleeful" ],
  "tags": [ "face", "grin" ],
  "tokens": [ ":d", "face", "gleeful", "grin", "grinning" ],
  "unicode": "😀",
  "version": 1,
  "emoticon": ":D"
}

Styling

emoji-picker-element uses Shadow DOM, so its inner styling cannot be changed with arbitrary CSS. Please refer to the API below for style customization.

Size

emoji-picker-element has a default size, but you can change it to be whatever you want:

emoji-picker {
  width: 400px;
  height: 300px;
}

For instance, to make it expand to fit whatever container you give it:

emoji-picker {
  width: 100%;
  height: 100%;
}

Dark mode

By default, emoji-picker-element will automatically switch to dark mode based on prefers-color-scheme. For more fine-grained, control, add the class dark or light to force dark/light mode:

<emoji-picker class="dark"></emoji-picker>
<emoji-picker class="light"></emoji-picker>

CSS variables

Most colors and sizes can be styled with CSS variables. For example:

emoji-picker {
  --num-columns: 6;
  --emoji-size: 3rem;
  --background: gray;
}

Here is a full list of options:

Variable	Default	Default (dark)	Description
--background	#fff	#222	Background of the entire <emoji-picker>
--border-color	#e0e0e0	#444
--button-active-background	#e6e6e6	#555555	Background of an active button
--button-hover-background	#d9d9d9	#484848	Background of a hovered button
--emoji-padding	0.5rem
--emoji-size	1.375rem
--indicator-color	#385ac1	#5373ec	Color of the nav indicator
--indicator-height	3px		Height of the nav indicator
--input-border-color	#999	#ccc
--input-border-radius	0.5rem
--input-border-size	1px
--input-font-color	#111	#efefef
--input-font-size	1rem
--input-line-height	1.5
--input-padding	0.25rem
--input-placeholder-color	#999	#ccc
--num-columns	8		How many columns to display in the emoji grid
--outline-color	#999	#fff	Focus outline color
--outline-size	2px		Focus outline width

Focus outline

For accessibility reasons, emoji-picker-element displays a prominent focus ring. If you want to hide the focus ring for non-keyboard users (e.g. mouse and touch only), then use the focus-visible polyfill, e.g.:

.js-focus-visible :focus:not(.focus-visible) {
  outline: none;
}

import { applyFocusVisiblePolyfill } from 'focus-visible';

const picker = new Picker();
applyFocusVisiblePolyfill(picker.shadowRoot);

emoji-picker-element already ships with the proper CSS for both the :focus_visible standard and the polyfill.

JavaScript API

Picker

import { Picker } from 'emoji-picker-element';
const picker = new Picker();
document.body.appendChild(picker);

The new Picker(options) constructor supports several options:

constructor

+ new Picker(__namedParameters: object): Picker

Parameters:

▪Default value __namedParameters: object= {}

Name	Type	Default	Description
dataSource	string	"https://cdn.jsdelivr.net/npm/emojibase-data@5/en/data.json"	URL to fetch the emojibase data from
i18n	object	-	i18n object (see below for details)
locale	string	"en"	Locale string

Returns: Picker

These values can also be set at runtime, e.g.:

const picker = new Picker();
picker.dataSource = '/my-emoji.json';

i18n structure

Here is the default English i81n object ("en" locale):

{
  "categories": {
    "smileys-emotion": "Smileys and emoticons",
    "people-body": "People and body",
    "animals-nature": "Animals and nature",
    "food-drink": "Food and drink",
    "travel-places": "Travel and places",
    "activities": "Activities",
    "objects": "Objects",
    "symbols": "Symbols",
    "flags": "Flags"
  },
  "categoriesLabel": "Categories",
  "emojiUnsupported": "Your browser does not support color emoji.",
  "loading": "Loading…",
  "networkError": "Could not load emoji. Try refreshing.",
  "regionLabel": "Emoji picker",
  "search": "Search",
  "searchResultsLabel": "Search results",
  "skinToneLabel": "Choose a skin tone"
}

Note that some of these strings are only visible to users of screen readers. But you should still support them if you internationalize your app!

Database

You can work with the database API separately, which allows you to query emoji the same way that the picker does:

import { Database } from 'emoji-picker-element';

const database = new Database();
await database.getEmojiBySearchPrefix('elephant'); // [{unicode: "🐘", ...}]

Full API:

constructor

+ new Database(__namedParameters: object): Database

Create a new Database.

Note that multiple Databases pointing to the same locale will share the same underlying IndexedDB connection and database.

Parameters:

▪Default value __namedParameters: object= {}

Name	Type	Default	Description
dataSource	string	"https://cdn.jsdelivr.net/npm/emojibase-data@5/en/data.json"	URL to fetch the emojibase data from
locale	string	"en"	Locale string

Returns: Database

close

▸ close(): Promise‹void›

Closes the underlying IndexedDB connection. The Database is not usable after that (or any other Databases with the same locale).

Returns: Promise‹void›

---

delete

▸ delete(): Promise‹void›

Deletes the underlying IndexedDB database. The Database is not usable after that (or any other Databases with the same locale).

Returns: Promise‹void›

---

getEmojiByGroup

▸ getEmojiByGroup(group: number): Promise‹Emoji]›

Returns all emoji belonging to a group, ordered by order.

Parameters:

Name	Type	Description
group	number	the group number

Returns: Promise‹[Emoji]›

---

getEmojiBySearchQuery

▸ getEmojiBySearchQuery(query: string): Promise‹[Emoji]›

Returns all emoji matching the given search query, ordered by order.

Parameters:

Name	Type	Description
query	string	search query string

Returns: Promise‹[Emoji]›

---

getEmojiByShortcode

▸ getEmojiByShortcode(shortcode: string): Promise‹[Emoji | null›

Return a single emoji matching the shortcode, or null if not found.

Parameters:

Name	Type	Description
shortcode	string

Returns: Promise‹Emoji | null›

---

getEmojiByUnicode

▸ getEmojiByUnicode(unicode: string): Promise‹Emoji | null›

Return a single emoji matching the unicode string, or null if not found.

Parameters:

Name	Type	Description
unicode	string	unicode string

Returns: Promise‹Emoji | null›

---

ready

▸ ready(): Promise‹void›

Resolves when the Database is ready, or throws an error if the Database could not initialize.

Note that you don't need to do this before calling other APIs – they will all wait for this promise to resolve before doing anything.

Returns: Promise‹void›

Emoji object

This object is returned as the Event detail in the emoji-click event, or when querying the Database. Here is the format:

interface Emoji {
  annotation: string;
  emoticon?: string;
  group: number;
  name: string;
  order: number;
  shortcodes: string[];
  tags?: string[];
  version: number;
  unicode: string;
}

Tree-shaking

If you want to import the Database without the Picker, or you want to code-split them separately, then do:

import Picker from 'emoji-picker-element/picker';
import Database from 'emoji-picker-element/database';

The reason for this is that Picker automatically registers itself as a custom element, following web component best practices. But this adds side effects, so bundlers like Webpack and Rollup do not tree-shake as well, unless the modules are imported from completely separate files.

Data and offline

Data source and JSON format

emoji-picker-element requires the full emojibase-data JSON file, not the "compact" one. If you would like to trim the JSON file down even further, then you can modify the JSON to only contain these keys:

[
  "annotation", "emoji", "emoticon", "group", 
  "order", "shortcodes", "tags", "version"
]

You can fetch the emoji JSON file from wherever you want. However, it's recommended that your server expose an ETag header – if so, emoji-picker-element can avoid re-downloading the entire JSON file over and over again. Instead, it will fire off a HEAD request and just check the ETag.

If the server hosting the JSON file is not the same as the one containing the emoji picker, then cross-origin server will also need to expose Access-Control-Allow-Origin: * and Access-Control-Allow-Headers: *. (Note that jsdelivr already does this, which is why it is the default.)

Unfortunately Safari does not support Access-Control-Allow-Headers, meaning that the ETag header will not be available cross-origin. In that case, emoji-picker-element will fall back to the less performant option. If you want to avoid this, host the JSON on the same server as your web app.

Offline-first

emoji-picker-element uses a "stale while revalidate" strategy to update emoji data. In other words, it will use any existing data it finds in IndexedDB, and lazily update via the dataSource in case that data has changed. This means it will work offline-first the second time it runs.

If you would like to manage the database yourself (e.g. to ensure that it's correctly populated before displaying the Picker), then create a new Database instance and wait for its ready() promise to resolve:

const database = new Database()
try {
  await database.ready()
} catch (err) {
  // Deal with any errors (e.g. offline)
}

If emoji-picker-element fails to fetch the JSON data the first time it loads, then it will display an error message.

Design decisions

IndexedDB

Why IndexedDB? Well, the emojibase-data English JSON file is 854kB, and the "compact" version is still 543kB. That's a lot of data to keep in memory just for an emoji picker. And it's not as if that number is ever going down; the Unicode Consortium keeps adding more emoji every year.

Using IndexedDB has a few advantages:

1. We don't need to keep half a megabyte of emoji data in memory at all times.
2. The second time your visitors visit your website, we don't even need to download, parse, and index the emoji data, because it's already available on their hard drive.

Native emoji

To avoid downloading a large sprite sheet (which may look out-of-place on different platforms, or may have IP issues), emoji-picker-element only renders native emoji. This means it is limited to the emoji actually installed on the user's device.

To avoid rendering ugly unsupported or half-supported emoji, emoji-picker-element will automatically detect emoji support and only render the supported characters. (So no empty boxes or awkward double emoji.)

JSON loading

Why only allow loading via a URL rather than directly passing in a JSON object? A few reasons:

First, it bloats the size of the JavaScript bundle to do so. emoji-picker-element is optimized for second load, where it doesn't even need to fetch, parse, or read the full JSON object into memory – it can just rely on IndexedDB. Sure, this could be optional, but if an anti-pattern is allowed, then people might do it out of convenience.

Second, browsers deal with JSON more efficiently when it's loaded via fetch() rather than embedded in JavaScript. It's faster for the browser to parse JSON than JavaScript, plus using the await (await fetch()).json() pattern gives the browser more room for optimizations, since you're explicitly telling it to cache and parse the data (asynchronously) as JSON. (I'm not aware of any browsers that do this, e.g. off-main-thread JSON parsing, but it's certainly possible!)

Browser support

emoji-picker-element only supports the latest versions of Chrome, Firefox, and Safari, as well as equivalent browsers (Edge, Opera, etc.).

Contributing

Install

yarn

Lint:

yarn lint

Fix most lint issues:

yarn lint:fix

Run the tests:

yarn test

Check code coverage:

yarn cover