How to get $context variables from the Watson Conversation Service in Unity?

Question

I'm trying to get the context variables that I made in Watson Conversation Dialogs in my Unity project. I am able to get the whole JSON dialog to show up in Unity, get the intents, entities and output text from the json file. So instead of getting the output:{ text[] out of the json file, I'm trying to get the context:{ variable:value out of the JSON file but I can't get my head around how.

This is the JSON file for the welcome dialog node where i want to read the destination_city variable out of to set it equal to an Unity variable/string.

{
   "context": {
     "date": null,
     "time": null,
     "hotel": null,
     "DateEnd": null,
     "DateBegin": null,
     "PeriodDate": null,
     "numberKids": null,
     "roomsHotel": null,
     "PeriodNumber": null,
     "numberAdults": 0,
     "departure_city": null,
     "transportation": null,
     "destination_city": "London",
     "kidDiscountRepeat": null
   },
   "output": {
     "text": {
       "values": [
         "Hello, this is the Watson Travel agency."
       ],
       "selection_policy": "sequential"
     }
   }
 }

And this is part of the code I have in Unity to get a response from Watson conversation and show the whole JSON file for that dialog node:

void HandleMessageCallback (object resp, Dictionary customData) 
{ object _tempContext = null; (resp as Dictionary ).TryGetValue("context", out _tempContext);

     if (_tempContext != null)
         conversationContext = _tempContext as Dictionary<string, object>;

     Dictionary<string, object> dict = Json.Deserialize(customData["json"].ToString()) as Dictionary<string, object>;

     // load output --> text;answer from Json node
     Dictionary <string, object> output = dict["output"] as Dictionary<string, object>;
     List<object> text = output["text"] as List<object>;
     string answer = text[0].ToString();
     Debug.Log("WATSON | Conversation output: \n" + answer);

     //======== Load $ context variable attempts =============================
     Debug.Log("JSON INFO: " + customData["json"].ToString());
     //=====================================

     if (conversationOutputField != null)
     {
         conversationOutputField.text = answer;
     }

Answer 1

Solution 1 : Keeping your code

Taking your current code, you should be able to access your context with

var context = dict["context"] as Dictionary<string, object>

Now that you have your context, you can access it's content in the same way

var mycity = context["destination_city"]

Conclusion 1

Even though this does work, if you are setting up a solution where you are going to manipulate/access Json, I highly advise making models of your data to serialize to and from, for this, check out Unity's JsonUtility (Json Serialization)

Solution 2 : Serialize C# Objects to and from Json

Let's take Unity's Manual example:

Data Model Class

First, we create a Model class of the Json information that we want, in this case, we want information about our player, for this we create 3 fields, int level, float timeElapsed and string playerName.

[Serializable]
public class MyClass
{
    public int level;
    public float timeElapsed;
    public string playerName;
}

Data initialization

Here we create a new Instance of our class MyClass called myObject and manually set it's fields values (in fact, how you set the values is not really important here)

MyClass myObject = new MyClass();
myObject.level = 1;
myObject.timeElapsed = 47.5f;
myObject.playerName = "Dr Charles Francis";

Serializing your class to Json

To serialize your myObject just pass it to JsonUtility's .ToJson method as parameter

string json = JsonUtility.ToJson(myObject);

Now, we have our class's object equivalent as a Json string:

{"level":1,"timeElapsed":47.5,"playerName":"Dr Charles Francis"}

Generating Json from your class

If you want to populate your C# Object with the data from your Json, you can do so by calling JsonUtility's .FromJson<TypeOfTheClassImMappingTo> Method and passing it the json string as parameter.

myObject = JsonUtility.FromJson<MyClass>(json);

These are only basic operations and the surface of what you could do with JsonUtility's Class/Json serialization

Conclusion 2

This solution is a lot more maintainable. You can extend it to use any number of model types, and have the advantage and ease of navigation of C# objects. This is particularly interesting to create systems which will use your Data Objects.

If you have questions about Json Utility, like how to manage arrays, nested data etc.. I highly advise taking a couple of minutes to read through @Programmers Answer about JsonUtility practices.

Ressources

[Unity - Manual] JsonUtility / JsonSerialization

[StackOverflow] Serialize and Deserialize Json and Json Array in Unity