Question

In my web app, I’m serializing objects for storage using JSON.stringify() as described here. This is great, and I can easily re-create the objects from the JSON strings, but I lose all of the objects’ methods. Is there a simple way to add these methods back to the objects that I’m overlooking – perhaps involving prototyping, something I’m not overly familiar with?

Or is it just a case of creating an elaborate function of my own for doing this?

Edit: Ideally, I’m looking for something like:

Object.inheritMethods(AnotherObject);

Answer 1

Once you have your object after calling JSON.parse, you have many options. Here’s a few examples.

1. Mixin

   There are many techniques for doing this, which this article describes nicely. However, here’s a simple example that doesn’t require any new language features. Remember that an object is essentially just a map, so JS makes it easy to add additional properties to an object.

   var stuffToAdd = function() {
       this.name = "Me";        
   
       this.func1 = function() {
           print(this.name);
       }
   
       this.func2 = function() {
           print("Hello again");
       }
   }
   
   var obj = JSON.parse("{}");
   stuffToAdd.call(obj);
   

2. Prototypical

   Use the Object.create method that Felix mentioned. Since this is only offered in ES5, you may want to use a shim to guarantee its availability.