How to Parse this JSON with LibGDX

Question

 "components":[  
        {  
           "class":"AssetReference",
           "asset":{  
              "class":"TextureRegionAsset",
              "relativePath":"gfx/opengraph.png"
           }
        },
        {  
           "class":"Layer"
        },
        {  
           "class":"ProtoVisSprite",
           "width":5,
           "height":5
        },
        {  
           "class":"Transform",
           "x":0.13817275,
           "y":2.8430145,
           "scaleX":0.2,
           "scaleY":0.2
        },
        {  
           "class":"Origin"
        },
        {  
           "class":"Tint"
        },
        {  
           "class":"Renderable",
           "zIndex":2
        },
        {  
           "class":"VisID",
           "id":"scratch"
        }
     ]

Im having some issues in parsing the nested asset with LibGDX. Does anyone know how to assign asset to AssetReference with the relativePath from TextureRegionAsset?

I know I could strip out the "class" handling and simple parse the JSON but I need to be able to handle this with LibGDX.

Ideally Im looking to parse the data and create a sprite from the JSON.

Thanks.

Answer 1

There is actually a useful libgdx wiki page for this:

https://libgdx.com/wiki/utils/reading-and-writing-json

Apparently it seems to work fine with nested classes on its own already. The wiki page has this example:

Json json = new Json();
Person person = json.fromJson(Person.class, text);

Using the following as text:

{
    class: com.example.Person,
    numbers: [
        {
            class: com.example.PhoneNumber,
            number: "206-555-1234",
            name: Home
        },
        {
            class: com.example.PhoneNumber,
            number: "425-555-4321",
            name: Work
        }
    ],
    name: Nate,
    age: 31
}

This is using an example class "Person" with the following properties:

• ArrayList numbers
• String name
• int age

The String text is the result of json.toJson(person). Your resulting serialized string seems the same format, which makes me assume you're already using the Json serializer, but not the unserializer.

Answer 2

You can use JsonReader and get JsonValue for that.

JsonReader json = new JsonReader();
JsonValue base = json.parse(Gdx.files.internal("file.json"));

//print json to console
System.out.println(base);

//get the component values
JsonValue component = base.get("components");

//print class value to console
System.out.println(component.getString("class"));

//array objects in json if you would have more components
for (JsonValue component : base.get("components"))
{
    System.out.println(component.getString("class"));
    System.out.println(component.get("asset").getString("class");
    System.out.println(component.get("asset").getString("relativePath");
}