Question

I have been trying to solve this tough problem but can’t come to a good approach.

So I have a JSON string:

{
   "fruit_color":{
     "apple":"",
     "banana":"",
     "orange":""
   }
}

I want to process this JSON to get an Object out of it which represents the class:

class FruitColor
{
    private var apple: String;
    private var banana: String;
    private var orange: String;

    public function FruitColor(apple: String, banana: String, orange: String)
    {
         this.apple=apple;
         this.banana=banana;
         this.orange=orange;
    }
}

Is this possible?
Would it be better if I use the JSON string and try to create code out of it?

The reason I need to do this is that I have a certain JSON I need to use to create class structures out of in ActionScript, Java, objective C to create libraries in those languages. So I am looking at something where I can specify all details once, so I dont have to individually monitor all the separate library codes.

Answer 1

Well, it is possible, but a JSON parser will not return you an instance of FruitColor, but an Object instead. So, with this JSON string, you will receive an object with a “fruit_color” field of type Object, that in turn will have three fields of type String. Say, this “fruit_color” actually determines the complete FruitColor instance, in this case you can do like this:

class FruitColor {
...
public function loadFrom(ob:Object):void {
     this.apple=ob.apple;
     this.banana=ob.banana;
     this.orange=ob.orange;
}
...
}

And call this, creating a new instance of FruitColor, then applying the parsed object within loadFrom(). Or, make a similar static function that will return a ready-made FruitColor object like this:

public static function loadFrom(ob:Object):FruitColor {
     var fc:FruitColor=new FruitColor();
     fc.apple=ob.apple;
     fc.banana=ob.banana;
     fc.orange=ob.orange;
     return fc;
}

Edit: Given that you want a *.as file out of a JSON object template, wanting a constructor that will provide necessary values, you need an approach similar to this:

public function makeClassFromObject(ob:Object):String {
    var header:String;
    var footer:String="}\n}";
    var cr:String=""; // constructor header
    var props:String="";
    var crbody:String="";
    for (var k:String in ob) {
        var the_ob=ob[k];
        if (the_ob is Object) {
            header="package { public class "+k+"{\n";
            cr="public function "+k+"(";
            for (k in the_ob) {
                var v:*=the_ob[k];
                var tt:String="Object"; // the type
                if (v is String) tt="String"; else
                if (v is int) tt="Number"; else 
                if (v is Number) tt="Number"; else 
                if (v is Array) tt="Array";
                props+="private var "+k+": "+tt+";\n";
                if (cr.charAt(cr.length-1)!='(') cr+=',';
                cr+=k+":"+tt;
                crbody+="this."+k+"="+k+";\n";
            }
            cr+="){\n";
            crbody+="}";
        } else {
            throw new Error("A nested Object is required!");
        }
        break; // we need ONE field in ob
    }
    return header+props+cr+crbody+footer;
 }