Base64 library, lossless transcoding.
npm install @cnwhy/base64编码,解码 库;- 二进制数据与 Base64 互转
- 字符串与 Base64 互转
npm i @cnwhy/base64
为何重复造轮子?
1. 需要单纯的Base64的库,而且能在浏览器上使用; (利用node的 对像的方法出局)
2. 支持字符串; (btoa , atob 只支持 Latin1);
4. Base64编/解码本该与字符串无关, 但现有库几乎只支持字符串;
5. 能用上Tree-shaking, 项目一般只用需要(encode 或 decode), 我可不想copy代码;
3. javascript 字符串无损转换 (因为这一点, 现有库几乎全军覆没), 具体例子;
6. 能应付异型Base64方案;兼容性
通用, 对于不支持ArrayBuffer的环境将会用Array代替Uint8Array.使用
`js
const { encode, decode, createEncode, createDecode } = require('@cnwhy/base64');
// import { encode, decode, createEncode, createDecode } from '@cnwhy/base64';// 1. 字符串
let str = '中国𐄡美国';
let b64 = encode(str);
console.log(b64);
let _str = decode(b64).toString(); // 必须调用toString()方法还原为字符串.
console.log('string:', str === _str); // true
// 2. 字节数组
// let buffer = fs.readFileSync('./test.js');
let buffer = new Uint8Array([0,255,127,33,0,5]);
let fb64 = encode(buffer); // encode支持 Buffer , Stirng, Array
let fu8arr = decode(fb64); // decode 返回Uint8Array对像
console.log('buffer:', Array.from(buffer).join() == Array.from(fu8arr).join());
// 3. 自定义 Base64 转换方法
// 自定义码表与补位符
const TABLE = 'xQh}s7*y~A|nkj4Bf%z1R,P+)mMS{(&EWCKegp6r!OXvHda$';
const PAD = '.';
// 自定义字符串编码/解码方法
const Utf16Encode = function(str) {
let cods = str.split('').map(s => s.charCodeAt(0));
return new Uint8Array(new Uint16Array(cods).buffer);
}
const Utf16Decode = function(arr) {
let u16 = Array.from(new Uint16Array(arr.buffer));
return u16.map(c => String.fromCharCode(c)).join('');
}
//创建自定义转码函数
const myEncode = createEncode(TABLE,PAD,Utf16Encode);
const myDecode = createDecode(TABLE,PAD,Utf16Decode);
console.log('\n自定义转码:');
let myb64 = myEncode(str);
console.log(myb64);
let my_str = myDecode(myb64).toString(); // 调用toString() 会用 Utf16Decode 方法将字节数组转为字符串
console.log('my:',str == my_str);
//output:
/*
5Lit5Zu98JCEoee+juWbvQ==
string: true
buffer: true
自定义转码:
nRvd,W})~(#4E$JP
my: true
*/
`
> 更多使用例子可以参看[这篇;API
ts
Base64 = {
BASE64_TABLE: "ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789+/";
BASE64_URL_TABLE: "ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789-_";
PAD: "=";
// UTF8 编码 解码; 可做为 strEncode strDecode 参数;
utf8Encode(str:string):Uint8Array|number[];
utf8Decode(utf8arr:Uint8Array|number[]):string; //Base64 编码 解码
encode(input:string|ArrayBuffer|Uint8Array|number[]):string;
decode(base64str: string) => number[]|Uint8Array;
//适用于URL的Base64 编码 解码( "_" "-" 替换 "/" "+");
encodeURL(input:string|ArrayBuffer|Uint8Array|number[]):string;
decodeURL(base64str: string) => number[]|Uint8Array;
//创建自定义Base64 encode , decode 函数
createEncode(strEncode: Function): (input: any) => string;
createEncode(table?: string[] | string, pad?: string, strEncode?: Function): (input: any) => string;
createDecode(strDecode: Function): (base64str: string) => Uint8Array | number[];
createDecode(table?: string[] | string, pad?: string, strDecode?: Function): (base64str: string) => Uint8Array | number[];
}
``