Format

This parser expects a JSON file with the following structure:

{
"classes" : {
    "MyClassName" : {
        ...
      }
  }
}

Within the classes object each property will represent a class, the name of the class will be its key and its definition, an object.

Class Definition

A class definition is an object whose properties can contain any value which JSON accepts, that is:

• Numbers
• Strings
• Lists
• Objects

So for example, the following would define a valid class within this format:

{
"classes": {
    "MyClassName": {
        "myIntProp": 13,
        "myFloatProp": 13.0,
        "myStrProp": "DummyValue",
        "myListProp": [1, 4, "Word", ["Inner", "List", "Values"]],
        "myObjProp": {
            "innerProp" : 3
         }
      }
  }
}

Classes can be named anything you want.

Class Inheritance

It is possible to inherit the properties of another class by using a specially reserver keywork Inherits as a property for a class. This property MUST be a list of strings where each string is the name of another class within the classes object.

The order of definition does not matter so long as it is properly named.

Example:

"classes": {
    "MyClassName": {
        "myIntProp": 13,
        "myFloatProp": 13.0,
        "myStrProp": "DummyValue",
        "myListProp": [1, 4, "Word", ["Inner", "List", "Values"]],
        "myObjProp": {
            "innerProp" : 3
         }
      },
      "SecondClassName" : {
        "Inherits": ["MyClassName"],
        "childProp": "This is a new value",
        "myStrProp": "This is overwritten by child"
      }
  }

As per standard inheritance rules, children will inherit all properties from their parents and if a property is redefined within the child then that value is the one that will be written.

The JSON above once parsed produces the following result:

"MyClassName": {
  "myFloatProp": 13.0,
  "myListProp": [1, 4, "Word", ["Inner", "List","Values"]],
  "myIntProp": 13,
  "myObjProp": {
    "innerProp": 3
  },
  "myStrProp": "DummyValue"
},
"SecondClassName": {
  "myFloatProp": 13.0,
  "myIntProp": 13,
  "myObjProp": {
    "innerProp": 3
  },
  "myStrProp": "This is overwritten by child",
  "myListProp": [1, 4, "Word", ["Inner", "List","Values"]],
  "childProp": "This is a new value"
}

It is important to note that the order of the properties is not important, but rest assured that inheritance is always solved first.

Private properties

It is also possible to define properties that are private to that class, that is, will not be inherited by any class that derives from them. this is done by prefixing the name of the property that will be private with the string $_.

Example:

{
"classes" : {
    "MyClassName" : {
        "$_MyPrivateProp": "This will not be inherited",
        "PublicProp": "This will be inherited"
     },
     "MyOtherClass": {
      "Inherits": ["MyClassName"]
     }
  }
}

The above JSON produces as a result:

{
  "MyClassName" : {
      "MyPrivateProp": "This will not be inherited",
      "PublicProp": "This will be inherited"
   },
   "MyOtherClass": {
     "PublicProp": "This will be inherited"
   }
}

Notice that the private prefix is dropped on the parsed result.

Class Reference

Class definitions also allow to reference another class in order to create an "instance" of that class, this is useful for composing classes in lists or other properties.

In order to reference another class simply write a string value which is the name of another class prefixed with the string ref_:

E.g: ref_MyClassName

Usage example:

{
"classes" : {
    "SwordClass" : {
        "name": "Sword",
        "weight": 50,
        "sharpness": 10
     },
     "ShieldClass": {
      "name": "Shield",
      "defense": 50
     },
     "WandClass": {
      "name": "Wand",
      "magic": 30
     },
     "BackpackClass": {
       "name": "Backpack",
       "contents": ["ref_SwordClass", "ref_ShieldClass", "ref_WandClass"]
     }
  }
}

The code above produces the following result:

{
  "ShieldClass": {
    "name": "Shield",
    "defense": 50
  },
  "WandClass": {
    "name": "Wand",
    "magic": 30
  },
  "SwordClass": {
    "name": "Sword",
    "weight": 50,
    "sharpness": 10
  },
  "BackpackClass": {
    "name": "Backpack",
    "contents": [
      {
        "name": "Sword",
        "weight": 50,
        "sharpness": 10
      },
      {
        "name": "Shield",
        "defense": 50
      },
      {
        "name": "Wand",
        "magic": 30
      }
    ]
  }
}

Script Usage

Simply run the script main.py with your formatted JSON using Python version 3.5 or above.

E.g: python3 main.py my_json_file.json

This will generate an output.json file with the parsed result.