HomeWork/react2/node_modules/js-base64/README.md

base64.js

Yet another Base64 transcoder

Usage

Install

$ npm install --save js-base64

If you are using it on ES6 transpilers, you may also need:

$ 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

<script src="base64.js"></script>

• Directly from CDN. In which case you don't even need to install.

<!-- the latest -->
<script src="https://cdn.jsdelivr.net/npm/js-base64/base64.min.js">

<!-- with version fixed -->
<script src="https://cdn.jsdelivr.net/npm/js-base64@2.6.4/base64.min.js">

node.js

var Base64 = require('js-base64').Base64;

es6+

import { Base64 } from 'js-base64';

SYNOPSIS

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 

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

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.

$ 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