Step 1: Create a Lambda Function

First, create a Lambda function which fulfills a pizza order. You specify this function in your Amazon Lex bot, which you create in the next section.

To create a Lambda function

1. Sign in to the AWS Management Console and open the AWS Lambda console at https://console.aws.amazon.com/lambda/.

2. Choose Create function.

3. On the Create function page, choose Author from scratch.

   Because you are using custom code provided to you in this exercise to create a Lambda function, you choose author the function from scratch.

   Do the following:

   1. Type the name (PizzaOrderProcessor).

   2. For the Runtime, choose the latest version of Node.js.

   3. For the Role, choose Create new role from template(s).

   4. Enter a new role name (PizzaOrderProcessorRole).

   5. Choose Create function.

4. On the function page, do the following:

   In the Function code section, choose Edit code inline, and then copy the following Node.js function code and paste it in the window.

   'use strict';
        
   // Close dialog with the customer, reporting fulfillmentState of Failed or Fulfilled ("Thanks, your pizza will arrive in 20 minutes")
   function close(sessionAttributes, fulfillmentState, message) {
       return {
           sessionAttributes,
           dialogAction: {
               type: 'Close',
               fulfillmentState,
               message,
           },
       };
   }
    
   // --------------- Events -----------------------
    
   function dispatch(intentRequest, callback) {
       console.log(`request received for userId=${intentRequest.userId}, intentName=${intentRequest.currentIntent.name}`);
       const sessionAttributes = intentRequest.sessionAttributes;
       const slots = intentRequest.currentIntent.slots;
       const crust = slots.crust;
       const size = slots.size;
       const pizzaKind = slots.pizzaKind;
       
       callback(close(sessionAttributes, 'Fulfilled',
       {'contentType': 'PlainText', 'content': `Okay, I have ordered your ${size} ${pizzaKind} pizza on ${crust} crust`}));
       
   }
    
   // --------------- Main handler -----------------------
    
   // Route the incoming request based on intent.
   // The JSON body of the request is provided in the event slot.
   export const handler = (event, context, callback) => {
       try {
           dispatch(event,
               (response) => {
                   callback(null, response);
               });
       } catch (err) {
           callback(err);
       }
   };

5. Choose Save.

Test the Lambda Function Using Sample Event Data

In the console, test the Lambda function by using sample event data to manually invoke it.

To test the Lambda function:

1. Sign in to the AWS Management Console and open the AWS Lambda console at https://console.aws.amazon.com/lambda/.

2. On the Lambda function page, choose the Lambda function (PizzaOrderProcessor).

3. On the function page, in the list of test events, choose Configure test events.

4. On the Configure test event page, do the following:

   1. Choose Create new test event.

   2. In the Event name field, enter a name for the event (PizzaOrderProcessorTest).

   3. Copy the following Amazon Lex event into the window.

      {
        "messageVersion": "1.0",
        "invocationSource": "FulfillmentCodeHook",
        "userId": "user-1",
        "sessionAttributes": {},
        "bot": {
          "name": "PizzaOrderingApp",
          "alias": "$LATEST",
          "version": "$LATEST"
        },
        "outputDialogMode": "Text",
        "currentIntent": {
          "name": "OrderPizza",
          "slots": {
            "size": "large",
            "pizzaKind": "meat",
            "crust": "thin"
          },
          "confirmationStatus": "None"
        }
      }

5. Choose Create.

AWS Lambda creates the test and you go back to the function page. Choose Test and Lambda runs your Lambda function.

In the result box, choose Details. The console displays the following output in the Execution result pane.

{
  "sessionAttributes": {},
  "dialogAction": {
    "type": "Close",
    "fulfillmentState": "Fulfilled",
    "message": {
      "contentType": "PlainText",
      "content": "Okay, I have ordered your large meat pizza on thin crust."
    }
}

Next Step

Step 2: Create a Bot