在这个问题被提出6年后,我发现这个问题仍然没有足够的答案;这应该实现以下所有:
关闭浏览器(或域的所有选项卡)后清除本地存储
如果至少有一个选项卡保持活动状态,则跨选项卡保留本地存储
重新加载单个选项卡时保留本地存储
在每个页面加载开始时执行这段javascript代码,以实现上述目标:
((nm,tm) => {
const
l = localStorage,
s = sessionStorage,
tabid = s.getItem(tm) || (newid => s.setItem(tm, newid) || newid)((Math.random() * 1e8).toFixed()),
update = set => {
let cur = JSON.parse(l.getItem(nm) || '{}');
if (set && typeof cur[tabid] == 'undefined' && !Object.values(cur).reduce((a, b) => a + b, 0)) {
l.clear();
cur = {};
}
cur[tabid] = set;
l.setItem(nm, JSON.stringify(cur));
};
update(1);
window.onbeforeunload = () => update(0);
})('tabs','tabid');
编辑:这里的基本思想如下:
When starting from scratch, the session storage is assigned a random id in a key called tabid
The local storage is then set with a key called tabs containing a object those key tabid is set to 1.
When the tab is unloaded, the local storage's tabs is updated to an object containing tabid set to 0.
If the tab is reloaded, it's first unloaded, and resumed. Since the session storage's key tabid exists, and so does the local storage tabs key with a sub-key of tabid the local storage is not cleared.
When the browser is unloaded, all session storage will be cleared. When resuming the session storage tabid won't exists anymore and a new tabid will be generated. Since the local storage does not have a sub-key for this tabid, nor any other tabid (all session were closed), it's cleared.
Upon a new created tab, a new tabid is generated in session storage, but since at least one tabs[tabid] exists, the local storage is not cleared