How do you serialise Ember objects?

Question

I need to use localStorage to store some Ember objects. I notice that Ember objects have properties with names like __ember1334992182483 . When I call JSON.stringify() on Ember objects, these __ember* properties are not serialised. Why is this? I'm not saying that I want to serialize those properties. I am just curious about what exactly they are and how they are implemented such that they are not serialised.

I am using cycle.js ( https://github.com/douglascrockford/JSON-js/blob/master/cycle.js ) to encode my data structures that contain duplicate references into a string that can be used for reconstructing the original data structures. It lets you do this:

a = {a:1}
b = {b:1}
c = [[a, b], [b, a]]

foo = JSON.stringify(JSON.decycle(c))  // "[[{'a':1},{'b':1}],[{'$ref':'$[0][1]'},{'$ref':'$[0][0]'}]]"
JSON.retrocycle(JSON.parse(foo))  // reconstruct c

For Ember objects I can do the same thing, but I also need to pass the deserialised objects into Ember.Object.create() because they are deserialised as plain JavaScript objects.

Is this the best way to serialise/deserialise Ember objects? Is there a recommended technique for this?

Answer 1

For serialization and deserialization you could do something along this lines, see http://jsfiddle.net/pangratz666/NVpng/ :

App.Serializable = Ember.Mixin.create({
    serialize: function() {
        var propertyNames = this.get('propertyNames') || [];
        return this.getProperties(propertyNames);
    },

    deserialize: function(hash) {
        this.setProperties(hash);
    }
});

App.Person = Ember.Object.extend(App.Serializable, {
    propertyNames: 'firstName title fullName'.w(),
    fullName: function() {
        return '%@ %@'.fmt(this.get('title'), this.get('firstName'));
    }.property('firstName', 'title')
});

var hansi = App.Person.create({
    firstName: 'Hansi',
    title: 'Mr.'
});

// { firstName: 'hansi', title: 'Mr.', fullName: 'Mr. Hansi' }
console.log( hansi.serialize() );

var hubert = App.Person.create();
hubert.deserialize({
    firstName: 'Hubert',
    title: 'Mr.'
});
console.log( hubert.serialize() );​

---

UPDATE : Also have a look at the similar question Ember model to json

Answer 2

我会使用ember-data并为此编写数据存储适配器。

Answer 3

I have:

• fixed and simplified code
• added circular reference prevention
• added use of get of value

• removed all of the default properties of an empty component

   //Modified by Shimon Doodkin //Based on answers of: @leo, @pangratz, @kevin-pauli, @Klaus //http://stackoverflow.com/questions/8669340 App.Jsonable = Em.Mixin.create({ getJson : function (keysToSkip, visited) { //getJson() called with no arguments, // they are to pass on values during recursion. if (!keysToSkip) keysToSkip = Object.keys(Ember.Component.create()); if (!visited) visited = []; visited.push(this); var getIsFunction; var jsonValue = function (attr, key, obj) { if (Em.isArray(attr)) return attr.map(jsonValue); if (App.Jsonable.detect(attr)) return attr.getJson(keysToSkip, visited); return getIsFunction?obj.get(key):attr; }; var base; if (!Em.isNone(this.get('jsonProperties'))) base = this.getProperties(this.get('jsonProperties')); else base = this; getIsFunction=Em.typeOf(base.get) === 'function'; var json = {}; var hasProp = Object.prototype.hasOwnProperty; for (var key in base) { if (!hasProp.call(base, key) || keysToSkip.indexOf(key) != -1) continue; var value = base[key]; // there are usual circular references // on keys: ownerView, controller, context === base if ( value === base || value === 'toString' || Em.typeOf(value) === 'function') continue; // optional, works also without this, // the rule above if value === base covers the usual case if (visited.indexOf(value) != -1) continue; json[key] = jsonValue(value, key, base); } visited.pop(); return json; } }); /* example: DeliveryInfoInput = Ember.Object.extend(App.Jsonable,{ jsonProperties: ["title","value","name"], //Optionally specify properties for json title:"", value:"", input:false, textarea:false, size:22, rows:"", name:"", hint:"" }) */