Using SharedObject with complicated classes

Question

I know that if I want to store a custom class with SharedObject, I have to use registerClassAlias.

registerClassAlias("MyClass", MyClass);
sharedObject.data.myObject = new MyClass();

But in my case, I have a custom class whose fields are themselves instances of custom classes. How can I store it in such a way as to recover the types when I load the data?

Specifically, the class in question is a Graph class which contains an array of Objects. This isn't the actual code, just an overview:

class Graph {
    public var vertices : Array;
}

I have an instance of this Graph class, and I'm filling its vertices field with instances of another class, called Node. I need to store this Graph instance in such a way that I can:

1. Recover it as a Graph instance.
2. Access the vertices field of this recovered instance, and then access the elements of that array as Node types.

I've tried throwing some registerClassAlias("Node", Node)'s in appropriate-seeming places, but it's not having any effect. Is there a way to do this?

Answer 1

With more complex data such as this, your best bet is to define load() and save() methods manually on objects that you want to store in a SharedObject. Those methods will define what data should be saved, simplified as much as possible, and collate it into a format of your choice such as JSON.

In this example, your Graph could have a method save() which looks like this:

public function save(name:String, sharedObject:SharedObject):void
{
    var list:Array = [];
    for each(var node:Node in vertices)
    {
        // Add a simple object defining the important Node properties
        // to the array we will save as JSON.
        list.push({ x: node.x, y: node.y });
    }

    sharedObject.data[name] = JSON.encode(list);
}

And then a load() function like so:

public function load(name:String, sharedObject:SharedObject):void
{
    // Empty current list of vertices.
    vertices = [];

    var list:Array = JSON.decode(sharedObject.data[name]);
    for each(var def:Object in list)
    {
        // Create real Node from simpler definition.
        var node:Node = new Node();

        node.x = def.x;
        node.y = def.y;
        vertices.push(node);
    }
}

Which would be utilized like:

existingGraph.save('myGraph', sharedObject);

var newGraph:Graph = new Graph();
newGraph.load('myGraph', sharedObject);