Microsoft Bot Framework – Forms dialog from JSON Schema.

What’s up guys, Eze is here. I’ve already written few posts about Microsoft Bot Framework, in case you missed it you can check it here. Today we are going deeper and review another really good feature of the Form Dialog, the possibility to create a form using a JObject. As we did before the Form Dialog is going to create a form and allow our Bot to ask field by field until 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 allows 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. And another important property for our form is the OnCompletion property, here we are going to put a C# script to execute after our bot complete to fulfill the form. And then we have the properties field where we are going to place the fields we want our bot ask to 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 create a method to return an object which implements the IForm interface as we did las time. As you can see in the code below we need use the FormBuilderJson object and we just pass the schema in the constructor.

 public static IForm<JObject>; 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 an use case where we want to provide to our customers a way to model their forms so we can define the form as a JSON Schema and provide them an admin screen to change it.

For mode details of Microsoft Bot Framework you can use this link.

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