shift73k/assets_old/node_modules/js-base64/README.md

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# base64.js
Yet another Base64 transcoder
## Usage
### Install
```javascript
$ npm install --save js-base64
```
If you are using it on ES6 transpilers, you may also need:
```javascript
$ npm install --save babel-preset-env
```
Note `js-base64` itself is stand-alone so its `package.json` has no `dependencies`.  However, it is also tested on ES6 environment so `"babel-preset-env": "^1.7.0"` is on `devDependencies`.
### In Browser
* Locally
```html
<script src="base64.js"></script>
```
* Directly from CDN. In which case you don't even need to install.
```html
<!-- the latest -->
<script src="https://cdn.jsdelivr.net/npm/js-base64/base64.min.js">
```
```html
<!-- with version fixed -->
<script src="https://cdn.jsdelivr.net/npm/js-base64@2.6.4/base64.min.js">
```
### node.js
```javascript
var Base64 = require('js-base64').Base64;
```
## es6+
```javascript
import { Base64 } from 'js-base64';
```
## SYNOPSIS
```javascript
Base64.encode('dankogai'); // ZGFua29nYWk=
Base64.btoa( 'dankogai'); // ZGFua29nYWk=
Base64.fromUint8Array( // ZGFua29nYWk=
new Uint8Array([100,97,110,107,111,103,97,105])
);
Base64.fromUint8Array( // ZGFua29nYW which is URI safe
new Uint8Array([100,97,110,107,111,103,97,105]), true
);
Base64.encode( '小飼弾'); // 5bCP6aO85by+
Base64.encodeURI('小飼弾'); // 5bCP6aO85by- which equals to Base64.encode('小飼弾', true)
Base64.btoa( '小飼弾'); // raises exception
```
```javascript
Base64.decode('ZGFua29nYWk='); // dankogai
Base64.atob( 'ZGFua29nYWk='); // dankogai
Base64.toUint8Array( // new Uint8Array([100,97,110,107,111,103,97,105])
'ZGFua29nYWk='
);
Base64.decode('5bCP6aO85by+'); // 小飼弾
// note .decodeURI() is unnecessary since it accepts both flavors
Base64.decode('5bCP6aO85by-'); // 小飼弾
Base64.atob( '5bCP6aO85by+'); // '小飼弾' which is nonsense
```
### String Extension for ES5
```javascript
if (Base64.extendString) {
// you have to explicitly extend String.prototype
Base64.extendString();
// once extended, you can do the following
'dankogai'.toBase64(); // ZGFua29nYWk=
'小飼弾'.toBase64(); // 5bCP6aO85by+
'小飼弾'.toBase64(true); // 5bCP6aO85by-
'小飼弾'.toBase64URI(); // 5bCP6aO85by-
'ZGFua29nYWk='.fromBase64(); // dankogai
'5bCP6aO85by+'.fromBase64(); // 小飼弾
'5bCP6aO85by-'.fromBase64(); // 小飼弾
}
```
### TypeScript
TypeScript 2.0 type definition was added to the [DefinitelyTyped repository](https://github.com/DefinitelyTyped/DefinitelyTyped).
```bash
$ npm install --save @types/js-base64
```
## `.decode()` vs `.atob` (and `.encode()` vs `btoa()`)
Suppose you have:
```
var pngBase64 =
"iVBORw0KGgoAAAANSUhEUgAAAAEAAAABCAQAAAC1HAwCAAAAC0lEQVR42mNkYAAAAAYAAjCB0C8AAAAASUVORK5CYII=";
```
Which is a Base64-encoded 1x1 transparent PNG, **DO NOT USE** `Base64.decode(pngBase64)`.  Use `Base64.atob(pngBase64)` instead.  `Base64.decode()` decodes to UTF-8 string while `Base64.atob()` decodes to bytes, which is compatible to browser built-in `atob()` (Which is absent in node.js).  The same rule applies to the opposite direction.
## SEE ALSO
+ http://en.wikipedia.org/wiki/Base64