Microsoft Bot Framework: Forms Dialog From JSON Schema

I've already written few posts about Microsoft Bot Framework. If you missed them, you can check out my posts here. Today, we are going deeper and reviewing another really good feature of Form Dialog. It involves the possibility to create a form using a JObject. As before, Form Dialog is going to create a form and allow our bot to ask field-by-field until it completes the form but instead of using a static C# class to define our form we are going to provide a JSON Schema.

In order to utilize this feature, you need to ensure that you add the NuGet project Microsoft.Bot.Builder.FormFlow.Json to your project. This defines the new namespace Microsoft.Bot.Builder.FormFlow.Json that contains the code to allow using JSON Schema for FormFlow.

Creating the JSON Schema

Now we need to define our form. This time, we are going to create a JSON file to do it. In the References property, we are going to define all the dependencies for our form. In the same way, under the Imports property, we define all the namespaces to include. Another important property for our form is the OnCompletion property. Here, we are going to put a C# script to execute after our bot completes to fulfill the form. Then, we have the properties field where we are going to place the fields we want our bot to ask the customer.

{ 
  "References": [ "CityTimerBot.dll" ], 
  "Imports": [ "CityTimerBot.Models" ], 
  "type": "object", 
  "required": [ "SelectedPlace" ], 
  "Templates": { 
    "NotUnderstood": { 
      "Patterns": [ "I do not understand \"{0}\".", "Try again, I don't get \"{0}\"." ] 
    } 
  }, 
  "properties": { 
    "PlaceName": { 
      "Prompt": { 
        "Patterns": [ "Name a place to know the current date-time {||}" ] 
      }, 
      "Before": [ { 
        "Message": [ "Welcome to the City Timer bot!" ] 
      } ], 
      "Describe": "Name of the place", 
      "type": [ "string", "null" ] 
    }, 
    "SelectedPlace": { 
      "Prompt": { 
        "Patterns": [ "Select a place {||}" ] 
      }, 
      "Before": [ { 
        "Message": [ "Welcome to the City Timer bot!" ] 
      } ], 
      "Describe": "Place to find the current date time", 
      "type": [ "string", "null" ] 
    } 
  }, 
  "OnCompletion": "var businesLogic = new CityTimerBot.Models.LocationBL(); var response = businesLogic.GetCityInfoFromPlaceId(state.SelectedPlace);var reply = string.Empty;if (!string.IsNullOrEmpty(response.cityName) && !string.IsNullOrEmpty(response.convertedLocalTime)){ reply = $\"Current date time at {response.cityName} is {response.convertedLocalTime}\"; }else{ reply = $\"Sorry we could not find any location called {state.PlaceName}\"; } await context.PostAsync(reply);" 
}

Once we have defined the schema file, we need to create a method to return an object which implements the IForm interface as we did last time. As you can see in the code below, we need to use the FormBuilderJson object and we just pass the schema in the constructor.

public static IForm; BuildJsonForm() { 
using (var stream = Assembly.GetExecutingAssembly().GetManifestResourceStream("CityTimerBot.LocationTemplate.json")) 
{ 
    var schema = JObject.Parse(new StreamReader(stream).ReadToEnd()); 
      return new FormBuilderJson(schema) .AddRemainingFields() .Build(); 
    } 
}

As you can see, this feature gives us the flexibility to define custom forms and the availability to change it dynamically. Thinking out loud, I can imagine a use case where we want to provide to our customers with a way to model their forms so we can define the form as a JSON Schema and provide them with an admin screen to change it.

For mode details about the Microsoft Bot Framework, you can use this link.

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