将JSON字符串转换为对象 [英] Convert JSON String to Objects

问题描述

我在JavaScript(Express.js/Mongoose)中有这样的JSON:

// create a document
var demo = new DemoSchema({
    hat: { money: "500" },
    functions: {
                func1: "this.hat.money - (0.02*this.hat.money)"
               }
});

现在，我想将此字符串用作对象.可以实现吗?

例如

DemoSchema.virtual('hat.newValue').get(function() {
    return this.functions.func1;
});

console.log('%s is 2% less', demo.hat.newValue); 

// above prints: this.hat.money - (0.02*this.hat.money is 2% less)

有关为什么要这样做的更多背景信息 https://groups.google.com/forum/#!topic/mongoose-users/lzyjg0b8Vn0

指针: JS中对象的字符串

更新的代码: http://jsfiddle.net/nottinhill/uktLr2g5/

解决方案

除了纯JavaScript解决方案，我们还与Brennan在 http://jsfiddle.net/nottinhill/uktLr2g5/5 以下解决方案适用于猫鼬存储函数:

var mongoose = require('mongoose')
require('mongoose-function')(mongoose);

var mySchema = mongoose.Schema({ func: Function });
var M = mongoose.model('Functions', mySchema);

var m = new M;
m.func = function(){
  console.log('stored function')
}
m.save(function (err) {
  M.findById(m._id, function (err, doc) {
    doc.func(); // logs "stored function"
  });
});

另请参阅: https://github.com/aheckmann/mongoose-function

I have such a JSON in JavaScript (Express.js/Mongoose):

// create a document
var demo = new DemoSchema({
    hat: { money: "500" },
    functions: {
                func1: "this.hat.money - (0.02*this.hat.money)"
               }
});

Now I want to use this string as objects. Can it be achieved?

e.g.

DemoSchema.virtual('hat.newValue').get(function() {
    return this.functions.func1;
});

console.log('%s is 2% less', demo.hat.newValue); 

// above prints: this.hat.money - (0.02*this.hat.money is 2% less)

More Background Info about why to do it this way: https://groups.google.com/forum/#!topic/mongoose-users/lzyjg0b8Vn0

Pointers: String to object in JS

Updated Code: http://jsfiddle.net/nottinhill/uktLr2g5/

解决方案

In addition to the JavaScript-only solution we worked out with Brennan at http://jsfiddle.net/nottinhill/uktLr2g5/5 the following solution will work for mongoose for storing functions:

var mongoose = require('mongoose')
require('mongoose-function')(mongoose);

var mySchema = mongoose.Schema({ func: Function });
var M = mongoose.model('Functions', mySchema);

var m = new M;
m.func = function(){
  console.log('stored function')
}
m.save(function (err) {
  M.findById(m._id, function (err, doc) {
    doc.func(); // logs "stored function"
  });
});

Also see: https://github.com/aheckmann/mongoose-function

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