MDN官网提供的cookie操作的辅助函数：
MDN document.cookie读写器函数（源码）：
/*\
|*|
|*| :: cookies.js ::
|*|
|*| A complete cookies reader/writer framework with full unicode support.
|*|
|*| https://developer.mozilla.org/en-US/docs/DOM/document.cookie
|*|
|*| This framework is released under the GNU Public License, version 3 or later.
|*| http://www.gnu.org/licenses/gpl-3.0-standalone.html
|*|
|*| Syntaxes:
|*|
|*| * docCookies.setItem(name, value[, end[, path[, domain[, secure]]]])
|*| * docCookies.getItem(name)
|*| * docCookies.removeItem(name[, path], domain)
|*| * docCookies.hasItem(name)
|*| * docCookies.keys()
|*|
\*/
var docCookies = {
// 获取
getItem: function (sKey) {
return decodeURIComponent(document.cookie.replace(new RegExp("(?:(?:^|.*;)\\s*" + encodeURIComponent(sKey).replace(/[-.+*]/g, "\\$&") + "\\s*\\=\\s*([^;]*).*$)|^.*$"), "$1")) || null;
},
// 设置/添加
setItem: function (sKey, sValue, vEnd, sPath, sDomain, bSecure) {
if (!sKey || /^(?:expires|max\-age|path|domain|secure)$/i.test(sKey)) { return false; }
var sExpires = "";
if (vEnd) {
switch (vEnd.constructor) {
case Number:
sExpires = vEnd === Infinity ? "; expires=Fri, 31 Dec 9999 23:59:59 GMT" : "; max-age=" + vEnd;
break;
case String:
sExpires = "; expires=" + vEnd;
break;
case Date:
sExpires = "; expires=" + vEnd.toUTCString();
break;
}
}
document.cookie = encodeURIComponent(sKey) + "=" + encodeURIComponent(sValue) + sExpires + (sDomain ? "; domain=" + sDomain : "") + (sPath ? "; path=" + sPath : "") + (bSecure ? "; secure" : "");
return true;
},
// 移除
removeItem: function (sKey, sPath, sDomain) {
if (!sKey || !this.hasItem(sKey)) { return false; }
document.cookie = encodeURIComponent(sKey) + "=; expires=Thu, 01 Jan 1970 00:00:00 GMT" + ( sDomain ? "; domain=" + sDomain : "") + ( sPath ? "; path=" + sPath : "");
return true;
},
// 判断是否存在
hasItem: function (sKey) {
return (new RegExp("(?:^|;\\s*)" + encodeURIComponent(sKey).replace(/[-.+*]/g, "\\$&") + "\\s*\\=")).test(document.cookie);
},
// 获取所有可用cookie的key列表
keys: /* optional method: you can safely remove it! */ function () {
var aKeys = document.cookie.replace(/((?:^|\s*;)[^\=]+)(?=;|$)|^\s*|\s*(?:\=[^;]*)?(?:\1|$)/g, "").split(/\s*(?:\=[^;]*)?;\s*/);
for (var nIdx = 0; nIdx < aKeys.length; nIdx++) { aKeys[nIdx] = decodeURIComponent(aKeys[nIdx]); }
return aKeys;
}
};
简易代码实现的随笔：
/**
* 获取单个cookie的值
* @param {string} key - cookie的键名
* @return {(string | object)}
*/
function getCookieItem(key) {
const cookies = document.cookie ? document.cookie.split('; ') : [];
const size = cookies.length;
let result = {};
for (let i = 0; i < size; i++) {
const [k, v] = cookies[i].split('=');
const name = decode(k);
if (name === key) {
result = decode(v);
break;
}
if (key === undefined && v) {
result[name] = decode(v);
}
}
return result;
}
/**
* cookie配置项的类型定义
* @typedef {Object} CookieOptions
* @prop {string} path - 路径
* @prop {string} domain - 域名
* @prop {number} maxAge - cookie的有效期
* @prop {(string | number | Date)} expires - UTC字符串（没有设置，则会在会话结束时过期）
* @prop {boolean} secure - 只允许https的协议传输
*/
/**
* 添加/设置cookie
* @param {string} key - cookie的键名
* @param {string} value - cookie的值
* @param {CookieOptions} [options={}] - cookie项的相关配置
* @return {boolean}
*/
function setCookieItem(key, value, options = {}) {
if (!key) {
return false;
}
let expires = '';
if (options.expires) {
switch(options.expires.constructor) {
case Number:
expires = options.expires === Infinity ? '; expires=Fri, 31 Dec 9999 23:59:59 GMT' : '; max-age=' + options.expires;
break;
case String:
expires = '; expires=' + options.expires;
break;
case Date:
expires = '; expires=' + options.expires.toUTCString();
break;
}
}
document.cookie = [
encode(key),
'=',
encode(value),
expires,
options.path ? '; path=' + options.path : '',
options.domain ? '; domain=' + options.domain : '',
options.secure ? '; secure' : '',
].join('');
return true;
}
/**
* 移除单个cookie记录
* @param {string} key - cookie的键名
* @param {CookieOptions} [options={}] - cookie项的相关配置
* @return {boolean}
*/
function removeCookieItem(key, options = {}) {
setCookieItem(key, '', { ...options, expires: -1 });
return !getCookieItem(key);
}
/**
* 编码URI字符串
* @param {(string | number | boolean)} uriComponent - 未编码的资源标识符的部分字符
* @return {string}
*/
function encode(uriComponent) {
return window.encodeURIComponent(uriComponent);
}
/**
* 解码URI字符串
* @param {string} encodedURIComponent - 编译后的资源标识符字符串
* @return {string}
*/
function decode(encodedURIComponent) {
return window.decodeURIComponent(encodedURIComponent);
}