Using Dialogs and Prompts to build a conversational BOT on Azure

A bot communicates with a user via conversations. To manage conversational flow we use dialogs.

According to Microsoft’s Azure BOT Builder SDK for Node.js , Dialogs can contain waterfall steps, and prompts.

They will be able to switch between dialogs according to the requirements during the conversation. To build a meaning full conversational bot we have to use dialogs smartly.

Here is a quick example,

// Create your bot with a function to receive messages from the user
var bot = new builder.UniversalBot(connector);
bot.set('storage', tableStorage);

bot.dialog('/', [
function (session) {
builder.Prompts.text(session, 'Hi! What is your name?');
},
function (session, results) {
session.endDialog(`Hello ${results.response}!`);
}
]);

It would produce the following coversation in result,

Some of  things you should know before using dialogs,

1. To start a new dialog (and push it onto the stack), use session.beginDialog().
2. To end a dialog (and remove it from the stack, returning control to the calling dialog), use either session.endDialog() or session.endDialogWithResult().
3. A prompt is used whenever a bot needs input from the user like builder.Prompts.text(session, ‘Hi! What is your name?’);

Waterfall model – Using Prompts to add features in the BOT

Adding choices as Buttons

bot.dialog('/', [
function (session) {
session.send("Welcome to the Pizza Place.");
builder.Prompts.choice(session, "What would you like to order today?", "Margherita|Cheese Pizza|Chicken Pizza", { listStyle: builder.ListStyle.button });
},
function (session, results) {
session.dialogData.pizzaOrder= results.response;
builder.Prompts.choice(session, "Which size do you prefer?", "Large|Medium|Small", { listStyle: builder.ListStyle.button });
},
function (session, results) {

session.dialogData.pizzaSize = results.response;
builder.Prompts.text(session, "Who's name will this order be under?");
},
function (session, results) {
session.dialogData.customerName = results.response;
session.send(`Order confirmed. Order details:

Pizza: ${session.dialogData.pizzaOrder}

Pizza size: ${session.dialogData.pizzaSize}

Customer name: ${session.dialogData.customerName}`);
session.endDialog();
}
]);

Choices as buttons would look like below, click them to choose:

Other Prompt Types:

For more details, visit the official docs here.