Alexa Request Interceptor - Cant kill the session

Question

Is it possible to have a RequestInterceptor abort the Session based on some logic inside the RequestInterceptor?

I have a routine coded that verifies the validity of a User. If the validity check fails, I want to play a message to the USer and abort the session.

What I see happening is that the LaunchRequest still runs even though I try and kill the seesion in the RequestInterceptor

A simplified version is as follows

const Alexa = require('ask-sdk-core');

const requestInterceptor = {
  var isUserOk = false;

  if(!isUserOk){
    process(handlerInput) {
     return handlerInput.responseBuilder
      .speak("You are inside the Request Interceptor")
      .withShouldEndSession(true)
      .getResponse();
    }
  }
}

const launchRequestHandler = {
  canHandle(handlerInput) {
    return (handlerInput.requestEnvelope.session.new && 
            handlerInput.requestEnvelope.request.type === 'LaunchRequest');
},
handle(handlerInput) {
  return handlerInput.responseBuilder
    .speak("Hi, welcome to the test skill. What is your name?")
    .reprompt("You did not respond. Please tell me your name")
    .getResponse();
  }
};

const skillBuilder = Alexa.SkillBuilders.custom();

exports.handler = skillBuilder
         .addRequestHandlers(
                  launchRequestHandler,
         )
        .addRequestInterceptors(
                 requestInterceptor
         )
        .lambda();

Can anyone tell me if it is possible to have the logic in the RequestInterceptor kill off the Session and prevent the LaunchRequest handler from running?

Thanks

-bc

Answer 1

It doesn't work because interceptors do not return responses (note that the interceptor method is called process() and not handle()) In the interceptor, instead of trying to close the session, use the handlerInput to set a session attribute named e.g. validUser:

let attributes = handlerInput.attributesManager.getSessionAttributes();
attributes.validUser = isUserOk(); //call your user check function here
handlerInput.attributesManager.setSessionAttributes(attributes);

Now create a launchRequestBadUserHandler where in the canHandle() you require that session attribute to be false:

const attributes = handlerInput.attributesManager.getSessionAttributes();
const isUserOk = attributes.validUser;
canHandle(handlerInput) {
        return (handlerInput.requestEnvelope.session.new && 
                handlerInput.requestEnvelope.request.type === 'LaunchRequest' &&
                !isUserOk);

In this handler handle() function send the response you originally planned for the interceptor. Don't forget to call this handler before your original launch request handler in addRequestHandlers()