javascript - 从 chrome 存储中检索日期对象不起作用

Question

在 Chrome 扩展中，我试图将 Date 对象保存到存储中，然后将其读回。根据official documentation ,

Values with a typeof "object" and "function" will typically serialize to {}, with the exception of Array (serializes as expected), Date, and Regex (serialize using their String representation).

我保存到存储为:

 var value= new Date(Date.now());
 chrome.storage.sync.set({"testdate":value}, function(){
     console.log("saved testdate to storage:");
     console.log(value);

 });

记录值的输出是

Tue Oct 16 2018 08:22:11 GMT-0700 (Pacific Daylight Time)

我后来从存储中检索为:

chrome.storage.sync.get("testdate", function(items){

        console.log("test date from storage:");
        console.log(items.testdate);
});

在这种情况下，记录 items.testdate 的值为:

Object proto: constructor: ƒ Object() hasOwnProperty: ƒ hasOwnProperty() isPrototypeOf: ƒ isPrototypeOf() propertyIsEnumerable: ƒ propertyIsEnumerable() toLocaleString: ƒ toLocaleString() toString: ƒ toString() valueOf: ƒ valueOf() defineGetter: ƒ defineGetter() defineSetter: ƒ defineSetter() lookupGetter: ƒ lookupGetter() lookupSetter: ƒ lookupSetter() get proto: ƒ proto() set proto: ƒ proto()

无法弄清楚如何取回我的 Date 对象(或将字符串表示形式转换回 Date)

Answer 1

设置面

const currentTime = (new Date()).toJSON();
const items = { 'testdate': currentTime }; 
chrome.storage.local.set(items, () => {
    if (chrome.runtime.lastError) {
        console.error(chrome.runtime.lastError.message);
    }
});

得到边

chrome.storage.local.get(['testdate'], (result) => {
    if (chrome.runtime.lastError) {
        console.error(chrome.runtime.lastError.message);
    } else {
        const storedJSONDate = result['testdate'];
        const testdate = new Date(storedJSONDate);
        console.log(testdate);
    }
});

来源

我的代码基于 Date.prototype.toJSON它说

var jsonDate = (new Date()).toJSON();
var backToDate = new Date(jsonDate);

console.log(jsonDate); //2015-10-26T07:46:36.611Z

来自 Chrome 存储 official documentation ，我认为这是说 Date 不会按预期进行序列化。因为它指定了 Array 和 Regex 如何序列化，而不是 Date 如何序列化，所以我认为它序列化为 {} ，这是我没有包含 toJSON() 时得到的部分。

An object which gives each key/value pair to update storage with. Any other key/value pairs in storage will not be affected. Primitive values such as numbers will serialize as expected. Values with a typeof "object" and "function" will typically serialize to {}, with the exception of Array (serializes as expected), Date, and Regex (serialize using their String representation).