Styjun

I have written my first Lambda to handle an Alexa Skill.

My problem is that the call to the database is clearly asynchronous (I can tell from the order the Console.log messages appear in the Cloud Log.

Here is my Handler.
How do I make it so the return happens after the data is got from the database?

const RemindMeHandler = 
 canHandle(handlerInput) ,
handle(handlerInput) 

 console.log('Started Reminder');

 var thing="Nothinbg";

/* ========== Read dB ========== */

 const params = 
 
 TableName: 'ItemsToRecall',
 Key: 
 'Slot': S: '1'
 ,
 ;


 readDynamoItem(params, myResult=>
 
 console.log('Reminder Results: ' + myResult.data);

 thing="Captain";
 console.log('thing 1: ' + thing); 
 );

 console.log('Ended Reminder');

 function readDynamoItem(params, callback) 
 

 var AWS = require('aws-sdk');
 AWS.config.update(region: 'eu-west-1');

 var docClient = new AWS.DynamoDB();

 console.log('Reading item from DynamoDB table');

 docClient.getItem(params, function (err, data) 
 
 if (err) 
 callback(err, data);
 else 
 callback('Worked', data);
 
 );


/* ========== Read dB End ========== */
console.log('thing 2: ' + thing);
return handlerInput.responseBuilder
 .speak(REMINDER_ACKNOWLEDGE_MESSAGE + thing)
 .getResponse();


;
/* ========== Remind Handler End ========== */

You can wrap the asynchronous and return a promise and then use async/await syntax to get the data. You can check the below. Do note it's not tested.

const RemindMeHandler = 
 canHandle(handlerInput) 
 return (
 handlerInput.requestEnvelope.request.type === "LaunchRequest" ,
 async handle(handlerInput) 
 console.log("Started Reminder");
 let thing = "Nothinbg";
 const params = 
 TableName: "ItemsToRecall",
 Key: 
 Slot: S: "1" 
 
 ;
 const data = await readDynamoItem(params);
 console.log("Reminder Results: ", data);
 thing = "Captain";
 let speechText = thing;
 return handlerInput.responseBuilder
 .speak(speechText)
 .reprompt(speechText)
 .getResponse();
 
;

function readDynamoItem(params) 
 const AWS = require("aws-sdk");
 AWS.config.update( region: "eu-west-1" );
 const docClient = new AWS.DynamoDB();
 console.log("Reading item from DynamoDB table");
 return new Promise((resolve, reject) => 
 docClient.getItem(params, function(err, data) 
 if (err) 
 reject(err);
 else 
 resolve(data);
 
 );
 );