将函数存储在IndexedDb数据存储区中 [英] Store a function in IndexedDb datastore

问题描述

是否可以以任何方式将函数存储在IndexedDB数据存储区中？我做了一些搜索，没有发现IndexedDB支持的数据类型。我尝试将函数和函数实例添加到对象存储中，如下所示，但它不起作用。

Is it possible in any way to store a function in an IndexedDB datastore? I have done some searching and found nothing on the data types that IndexedDB supports. I tried simply adding a function and the instance of a function to an object store as follows, but it didn't work.

var myclass = function () {
    self = this;
    self.name = 'Sam';
    self.hello = function () {
        console.log('Hello ' + self.name);
    };
}

var transaction = db.transaction(['codeobject'], 'readwrite');
var store = transaction.objectStore('codeobject');
var request = store.put({ 'classname': 'someclass', 'object': myclass });

我试过了。

var request = store.put({ 'classname': someclass', 'object': new myclass() });

我真的想要在对象db中存储一个类。即使我不得不将它存储为某种类型的blob，然后在出路时将其序列化为函数。

I would really like to be about to store a class in object db. Even if I had to store it as some type of blob and then serialize it back into a function on its way out.

谢谢

推荐答案

如果我的问题是正确的，你想要做的是序列化整个对象，包括函数？

If I get your question right, what you want to do is serialize the entire object including functions?

这是可能的，您只需要可以序列化函数。有关它的更多信息，请参阅我的博客 。

This is possible to do, you only need to make it possible to serialize functions. For more information about it, see my blogpost about it.

function serialize(key, value) {
    if (typeof value === 'function') {
        return value.toString();
    }
    return value;
}

function deserialize(key, value) {
    if (value && typeof value === "string" && value.substr(0, 8) == "function") {
        var startBody = value.indexOf('{') + 1;
        var endBody = value.lastIndexOf('}');
        var startArgs = value.indexOf('(') + 1;
        var endArgs = value.indexOf(')');

        return new Function(value.substring(startArgs, endArgs), value.substring(startBody, endBody));
    }
    return value;
}

var jsonObj = {
    func: function(){ return ""; }
}
// Turns an object into a json string including functions
var objectstring = JSON.stringify(jsonObj, serialize);

// Turns an object string in JSON into an object including functions.
var object = JSON.parse(objectstring , deserialize);

然后，您获得的objectstring可以保存到indexeddb中。

The objectstring you get can then be saved into the indexeddb.

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