Alexa Skills: Lambda function to read contents from a file in S3 - amazon-s3

Question

I have an Alexa Skill that tries to read the contents from a file stored in S3. The test event for the Lambda function for Alexa Start Session is successful. I understand that there is something wrong with my CompletedMyIntentHandler but I can't quite seem to figure it out. Any help on it is much appreciated. The lambda function takes help from https://github.com/alexa/alexa-cookbook/blob/master/aws/Amazon-S3/read/. Find my Lambda function below;
const Alexa = require('ask-sdk');
// 1. Text strings =====================================================================================================
// Modify these strings and messages to change the behavior of your Lambda function
const helpOutput = 'You can demonstrate the S3 Storage read capability by saying "Hello".';
const helpReprompt = 'Try saying "Hello World".';
var myBucket = 'jailalita'; // replace with your own bucket name!
var myObject = 'hello.txt'; // replace with your own file name!
// 2. Intent Handlers =============================================
const CompletedMyIntentHandler = {
canHandle(handlerInput) {
const request = handlerInput.requestEnvelope.request;
return request.type === 'IntentRequest' && request.intent.name === 'MyIntent';
},
handle(handlerInput) {
console.log('My Intent - handle');
const responseBuilder = handlerInput.responseBuilder;
const speechOutput = MyIntent();
return responseBuilder
.speak(speechOutput)
.getResponse();
},
};
const HelpHandler = {
canHandle(handlerInput) {
const request = handlerInput.requestEnvelope.request;
return request.type === 'IntentRequest' && request.intent.name === 'AMAZON.HelpIntent';
},
handle(handlerInput) {
const responseBuilder = handlerInput.responseBuilder;
return responseBuilder
.speak(helpOutput)
.reprompt(helpReprompt)
.getResponse();
},
};
const CancelStopHandler = {
canHandle(handlerInput) {
const request = handlerInput.requestEnvelope.request;
return request.type === 'IntentRequest' && (request.intent.name === 'AMAZON.CancelIntent' || request.intent.name === 'AMAZON.StopIntent');
},
handle(handlerInput) {
const responseBuilder = handlerInput.responseBuilder;
const speechOutput = 'Okay, talk to you later! ';
return responseBuilder
.speak(speechOutput)
.withShouldEndSession(true)
.getResponse();
},
};
const SessionEndedHandler = {
canHandle(handlerInput) {
const request = handlerInput.requestEnvelope.request;
return request.type === 'SessionEndedRequest';
},
handle(handlerInput) {
console.log(`Session ended with reason: ${handlerInput.requestEnvelope.request.reason}`);
return handlerInput.responseBuilder.getResponse();
},
};
const ErrorHandler = {
canHandle() {
return true;
},
handle(handlerInput, error) {
const request = handlerInput.requestEnvelope.request;
console.log(`Original Request was: ${JSON.stringify(request, null, 2)}`);
console.log(`Error handled: ${error}`);
return handlerInput.responseBuilder
.speak('Sorry, I can not understand the command. Please say again.')
.reprompt('Sorry, I can not understand the command. Please say again.')
.getResponse();
},
};
// 3. Helper Function =================================================================================================
function MyIntent() {
var myParams = {
Bucket: myBucket,
Key: myObject
};
S3read(myParams, myResult => {
console.log("sent : " + JSON.stringify(myParams));
console.log("received : " + myResult);
var speech = this.response.speak('The S 3 file says, ' + myResult );
return speech;
}
);
}
function S3read(params, callback) {
// call AWS S3
var AWS = require('aws-sdk');
var s3 = new AWS.S3();
s3.getObject(params, function(err, data) {
if(err) { console.log(err, err.stack); }
else {
var fileText = data.Body.toString(); // this is the complete file contents
callback(fileText);
}
});
}
// 4. Exports handler function and setup ===================================================
const skillBuilder = Alexa.SkillBuilders.custom();
exports.handler = skillBuilder
.addRequestHandlers(
//LaunchRequestHandler,
CompletedMyIntentHandler,
HelpHandler,
CancelStopHandler,
SessionEndedHandler,
)
.addErrorHandlers(ErrorHandler)
.lambda();
JSON Input
{
"version": "1.0",
"session": {
"new": true,
"sessionId": "amzn1.echo-api.session.e6f74d95-8d55-4aac-ade0-dd4ff4ed4f04",
"application": {
"applicationId": "amzn1.ask.skill.5edd47bc-525d-4ef4-9b6e-a83a7e79744f"
},
"user": {
"userId": "amzn1.ask.account.AF4SLRK5TC4SDSHL7LGK2IB6SMXCPGS7Y6YKYLPDGWRE7CA3K6MCKVVUW2OFMVCWJFXZDQBSYY5Z2RXZWQAJLDCMR3SXYCVA7ZARDRNQXA3TXBM4ILP77FKNOO4MCVPLWHIXW3QNZCRYPDQ7CCBP6QT7GMTBMQX2BVCNS22SZL4MC6WB7GDS44XN2DKGJQBMGIDQ3O7RBYD6GAI"
}
},
"context": {
"System": {
"application": {
"applicationId": "amzn1.ask.skill.5edd47bc-525d-4ef4-9b6e-a83a7e79744f"
},
"user": {
"userId": "amzn1.ask.account.AF4SLRK5TC4SDSHL7LGK2IB6SMXCPGS7Y6YKYLPDGWRE7CA3K6MCKVVUW2OFMVCWJFXZDQBSYY5Z2RXZWQAJLDCMR3SXYCVA7ZARDRNQXA3TXBM4ILP77FKNOO4MCVPLWHIXW3QNZCRYPDQ7CCBP6QT7GMTBMQX2BVCNS22SZL4MC6WB7GDS44XN2DKGJQBMGIDQ3O7RBYD6GAI"
},
"device": {
"deviceId": "amzn1.ask.device.AETD2DDUWNTWA5BNNDFHCRT26SLOZUTZUFJ5P3OEQGDCWWDSFWPKNONGMT4KZAJPUB6ZRD3YVCDEVFAGPLXHVP6XESWS6BKEYZHZRXT25QNK2RTFNUG4PKD347P5DAWE2H4WQLGTQVLNQ5JNFGHFUSUC3X7Q",
"supportedInterfaces": {}
},
"apiEndpoint": "https://api.amazonalexa.com",
"apiAccessToken": "eyJ0eXAiOiJKV1QiLCJhbGciOiJSUzI1NiIsImtpZCI6IjEifQ.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.Fc-aAcaf4qTgf489cQsZ44KTq-yZ-xMJCBenq9DbpppkMgSscF0NodGYTK967AcGblwqOFqcwIC1PvGmISER9oDH5TIhKF1kLsTimRHRKsttElRl7FIEvki-sKLD4VTeStTKM-w5laBm6urAzlCXpJySU-InVH5_qE0M5LHnLZRrE_qy7EmIq2vsrq2Cekve-gQ3Y3ImW3_0b7ikg6gwO6si-O0IxXO6hxS5sTuQH4f4aRybHVO3jflHD7g7pGPFzfkpc_tg6KFkhFv6CMvkx25A2u7iO7vVQpMHdj-_2ZM0ZmO9JuP-v7ydKYT_1IDjfpZKfvgIGyYsNfCPDY5F2Q"
}
},
"request": {
"type": "LaunchRequest",
"requestId": "amzn1.echo-api.request.12ef23e3-a7e5-48a4-90f9-de9c253f72b9",
"timestamp": "2018-07-02T05:39:24Z",
"locale": "en-US",
"shouldLinkResultBeReturned": false
}
}
JSON Output
{
"body": {
"version": "1.0",
"response": {
"outputSpeech": {
"type": "SSML",
"ssml": "<speak>Sorry, I can not understand the command. Please say again.</speak>"
},
"reprompt": {
"outputSpeech": {
"type": "SSML",
"ssml": "<speak>Sorry, I can not understand the command. Please say again.</speak>"
}
},
"shouldEndSession": false
},
"sessionAttributes": {},
"userAgent": "ask-node/2.0.0 Node/v8.10.0"
}
}
JSON Editor
{
"interactionModel": {
"languageModel": {
"invocationName": "hello world",
"intents": [
{
"name": "AMAZON.FallbackIntent",
"samples": []
},
{
"name": "AMAZON.CancelIntent",
"samples": []
},
{
"name": "AMAZON.HelpIntent",
"samples": []
},
{
"name": "AMAZON.StopIntent",
"samples": []
},
{
"name": "MyIntent",
"slots": [],
"samples": [
"hello"
]
}
],
"types": []
}
}
}

Answer 1

You can't build your response and return inside the S3Read function as it's an async call to an external service. You need to wait for that call using async/await and once you get a value then craft the response and return.