mirror of
https://github.com/twitter/twemoji.git
synced 2024-06-15 03:35:16 +00:00
0bff51c31b
* Initial split of README into legacy and contributing * Update contributing steps
323 lines
9.3 KiB
Markdown
323 lines
9.3 KiB
Markdown
# Twemoji Legacy API (V1)
|
||
|
||
## Usage
|
||
|
||
### CDN Support
|
||
|
||
The folks over at [MaxCDN](https://www.maxcdn.com) have graciously provided CDN support.
|
||
|
||
Use the following in the `<head>` tag of your HTML document(s):
|
||
|
||
```html
|
||
<script src="https://twemoji.maxcdn.com/1/twemoji.min.js" crossorigin="anonymous"></script>
|
||
```
|
||
|
||
This guarantees that you are using the V1 version of the library.
|
||
|
||
### Download
|
||
|
||
If instead you want to download a specific version, please look at the `gh-pages` branch, where you will find the built assets for our legacy versions.
|
||
|
||
## API
|
||
|
||
Following are all the methods exposed in the `twemoji` namespace.
|
||
|
||
### twemoji.parse( ... )
|
||
|
||
This is the main parsing utility and has 3 overloads per parsing type.
|
||
|
||
There are mainly two kinds of parsing: [string parsing](https://github.com/twitter/twemoji#string-parsing) and [DOM parsing](https://github.com/twitter/twemoji#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
|
||
|
||
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.
|
||
|
||
```js
|
||
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.
|
||
|
||
```js
|
||
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.
|
||
|
||
```js
|
||
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.
|
||
|
||
```js
|
||
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*.
|
||
|
||
```js
|
||
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.
|
||
|
||
```js
|
||
{
|
||
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:
|
||
|
||
```js
|
||
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
|
||
|
||
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:
|
||
|
||
```js
|
||
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.
|
||
|
||
```js
|
||
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.
|
||
|
||
```js
|
||
twemoji.convert.fromCodePoint('1f1e8');
|
||
// "\ud83c\udde8"
|
||
```
|
||
|
||
### twemoji.convert.toCodePoint()
|
||
|
||
For given UTF-16 surrogate pairs, returns the equivalent HEX codepoint.
|
||
|
||
```js
|
||
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:
|
||
|
||
```css
|
||
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>`
|
||
|
||
```html
|
||
<meta charset="utf-8">
|
||
```
|
||
|
||
### Exclude Characters
|
||
|
||
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:
|
||
|
||
```js
|
||
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);
|
||
}
|
||
});
|
||
```
|
||
|
||
## 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.
|