I made a Lex Bot to order milk but whenever i completed the process and exit the bot my transaction got erased. I am not able to see my last transaction. I want to know how can i save my previous details so i can enquire it in future?
var AWS = require('aws-sdk');
var dynamodb = new AWS.DynamoDB({apiVersion: '2012-08-10'});
exports.handler = (event, context, callback) =>{
var amount = event.currentIntent.slots.amount;
var params1 = {
Key: {
"last_Transaction": {
S: " "
},
},
TableName: "confirmation_Table"
};
dynamodb.getItem(params1, function(err, data) {
if (err) console.log(err, err.stack); // an error occurred
else
{console.log(data); // successful response
}
});
callback(null, {
"dialogAction":{
"type":"Close",
"fulfillmentState": "Fulfilled",
"message": {
"contentType": "PlainText",
"content": amount
}
}
});
};
You should save the transactions in some file or database, where you can read them in future. DynamoDB is good choice.
Before exiting the bot you can store the transaction with unique id in the DynamoDB.
You can use put_item(),read about them at DynamoDB docs
Below is the pseudo code:
Get info from user
Validate in DialogCodeHook
Come to FulfillmentCodeHook
Save info in DynamoDB
Close
Related
I am trying to pull and display data from DynamoDb by using AWS Lambda function and have it display on AWS Lex. It is returning the if portion with the word "undefined" in the place where the data should be. The information is in the DynamoDB database. I am mainly using AWS servers and building this serverless Lex bot application.
AWS code Segments
const AWS = require('aws-sdk');
const db = new AWS.DynamoDB.DocumentClient({region: 'us-east-1'});
exports.handler = async (event) => {
// TODO implement
const response = {
statusCode: 200,
body: JSON.stringify('Hello from Lambda!'),
};
return response;
};
function getExamSchedule(exam2, table){
return new Promise(function(resolve){
var info = 0;
var params = {
TableName: table,
FilterExpression: "#key = :data",
ExpressionAttributeNames: {
"#key": "Resource",
},
ExpressionAttributeValues:{
":data": exam2
}
};
db.scan(params, function(err, data){
if(err){
console.log("Error: " + err);
info = 0;
} else {
console.log("Success", data);
info = {"ClassID" :data.Items[0].ClassID, "ExamDate " :data.Items[0].ExamDate,
"ExamEndTime:" :data.Items[0].ExamEndTime, "ExamLocation" :data.Items[0].ExamLocation,
"ExamStartTime" :data.Items[0].ExamStartTime};
}
resolve(info);
});
});
}
This is the portion where the issue might be occurring.
exports.handler = async (event, context, callback) => {
var exam2 = event.currentIntent.slots.ClassID;
var info = await getExamSchedule(exam2, "Final_Exams");
var res;
// if (info !== 0)
if(info != null){
res =`The exam information for ${exam2} is ${info.ClassID} Date: ${info.ExamDate}
End time: ${info.ExamEndTime} Location: ${info.ExamLocation} Start time: ${info.ExamStartTime}`;
} else {
res = `The exam is not entered into our database, please look for another exam.`;
}
callback(null, {
"dialogAction": {
"type":"Close",
"fulfillmentState": "Fulfilled",
"message":{
"contentType": "PlainText",
"content": res
}
}
});
};
Could you perhaps share some of the logs and/or stack traces that you encounter when running the code?
I am querying dynamodb from lambda function written in node.js env -
Trying to query for table CurrencyPrice where Currency column has value "BLC".
When I test my function in lambda console, - it prints until second console log - "querying DB ConsolePrice" and returns a NULL response. It does not print either of the next two console logs and not sure if it is even connecting to DB.
It seems that the code does not go into ddb.query() function at all - had tried putting all loggers in this function but none gets printed.
I have tried checking all possible aws documentation but not able to understand why this function is not getting executed.
My code looks something like below -
var AWS = require ('aws-sdk');
exports.handler = async (event) =>
{
AWS.config.update({region: 'ap-southeast-2'});
console.log("i am in function");
// Create DynamoDB service object
var ddb = new AWS.DynamoDB.DocumentClient();
var table = 'CurrencyPrice';
var params = {
"Select": "ALL_ATTRIBUTES","TableName": "CurrencyPrice",
};
console.log("querying DB" + table);
ddb.query(params, function(err, data) {
console.log("i am in ddb query");
if (err) {
console.error("Unable to query. Error:", JSON.stringify(err, null,2));
} else {
console.log(data);
}
});
};
Current result that I am getting in lambda console:
Response:
null
Request ID:"XXXX"
Function Logs:
START RequestId: XXX Version: $LATEST
2019-06-02T13:31:55.189Z XXXX INFO i am in function
2019-06-02T13:31:55.331Z XXXX INFO querying DBCurrencyPrice
2019-06-02T13:31:55.390Z XXXX INFO { Select: 'ALL_ATTRIBUTES', TableName: 'CurrencyPrice' }
END RequestId: XXXX
I expect that at least it prints "Unable to Query" or actual data that it connects to DB and query?
If you're using async/await you would want to return a promise.
var AWS = require("aws-sdk");
AWS.config.update({ region: "ap-southeast-2" });
var ddb = new AWS.DynamoDB.DocumentClient();
exports.handler = async event => {
console.log("i am in function");
// Create DynamoDB service object
var table = "CurrencyPrice";
var params = {
Select: "ALL_ATTRIBUTES",
TableName: "CurrencyPrice"
};
console.log("querying DB" + table);
return ddb
.query(params)
.promise()
.then((err, data) => {
console.log("i am in ddb query");
if (err) {
console.error("Unable to query. Error:", JSON.stringify(err, null, 2));
} else {
console.log(data);
}
});
};
The AWS example
ddbClient.query(params, callback)
shows a synchronous matter. Execution continues without waiting for the callback finishes. That's why you got Null.
You will have to wrap this .query() call into a Promise, so the execution will wait for completion of this callback.
Make query a promise and wait for its fulfilled state.
const promise = await ddb.query(params, function(err, data) {
console.log("i am in ddb query");
if (err) {
console.error("Unable to query. Error:", JSON.stringify(err, null,2));
} else {
console.log(data);
// process your data
}
}).promise();
return promise;
I've been stuck on this code for about a day now.
I am just trying to add information into DynamoDB through a launch request using Alexa.
I get the following error code:
"errorMessage": "RequestId: f96ae2cb-1dbf-11e7-a267-b7cf2f2c95a0 Process exited before completing request"
The information actually gets inserted into DynamoDB, but I can't add more functions to the program because of the error.
From what I understand, it may be a problem with the callback.
I have tried many different ways to "callback" or return something, but I haven't figured out how to avoid the error.
If I uncomment this.emit(':tell', "Hello, inserting Apples into DynamoDB"); the error goes away, but no information gets inserted.
What am I doing wrong and how can I fix it?
Below is my code;
'use strict';
var Alexa = require('alexa-sdk');
const doc = require('dynamodb-doc');
const dynamo = new doc.DynamoDB();
exports.handler = function(event, context, callback) {
var alexa = Alexa.handler(event, context);
alexa.registerHandlers(handlers);
alexa.execute();
};
var handlers = {
'LaunchRequest': function(event, context, callback) {
// this.emit(':tell', "Hello, inserting Apples into DynamoDB");
var params = {
Item: {
date: Date.now(),
message: "Apples"
},
TableName: '_yourTableName'
};
dynamo.putItem(params, function(err, data) {
if (err) {
callback(err, null);
} else {
callback(null, data);
}
});
context.done();
}
};
This is because you are adding values to Dynamodb, which is a callback but context.done(); is written outside the callback. Before dynamoDb completes the operation it will call context.done(); hence it will exit the process
I got the following flow:
Put file to S3
Triggered Lambda function
DynamoDB table
Due to this flow, I created an integration test which first put a file to S3.
After that, I checked the record over the DynamoDB table which been updated by the Lambda function.
The problem occures when I'm searching for my record, actually I couldn't find it because there is some time interval that I need to wait for the table to be updated. In the second run I was able to see the record from the previous test run.
My question is how can I make this integration test? How can I check for the updated table records after which needs to be inserted after some time using the lambda trigger call.
What I tried so far:
Use Promise
Use setTimeout()
These weren't good enough for me, Please advice some better approach.
My code:
it('Writing single record to DynamoDB - when data is valid JSON and updating the DB is Succeed',
function(done) {
var putObjectParams = {
Bucket: BUCKET,
Key: FILE_KEY,
Body: 'some file content'
};
s3.putObject(putObjectParams, function(err, data) {
if (err) {
console.log(err, err.stack);
} else {
console.log(JSON.stringify(data));
}
});
var docClient = new AWS.DynamoDB.DocumentClient();
var queryParams = {
TableName: ENV + "-WFMHistoricalUnprocessedFiles",
ProjectionExpression: "filePath, ingressTime, dir, fileName",
KeyConditionExpression: "#column = :fileFullPath",
ExpressionAttributeNames: {
"#column": "filePath"
},
ExpressionAttributeValues: {
":fileFullPath": BUCKET + "/" + FILE_KEY
}
};
docClient.query(queryParams, function(err, data) {
if (err) {
console.log("Unable to query. Error:", JSON.stringify(err, null, 2));
} else {
console.log("Query succeeded.");
data.Items.forEach(function(item) {
console.log(JSON.stringify(item));
});
}
});
});
I have a use case of pushing SNS notifications from Amazon lambda. I have written the following code, with the IAM role having the permission to invoke SNS. Even with the Kenesis trigger, this Lambda function is unable to send any notification to SNS. I confirmed this by, subscribing my email id to the SNS.
[EDIT]: Just a follow up question. I now need to query DynamoDB and based on the output, need to call different end point of SNS. Now, when I query DynamoDB, the execution stops after DynamoDB query and not even progressing for SNS checks.
Following is my lambda function code.
console.log('Loading function');
var AWS = require('aws-sdk');
exports.handler = function(event, context) {
event.Records.forEach(function(record) {
//var payload = new Buffer(record.kinesis.data, 'base64').toString('ascii');
var payload = record.kinesis.data;
console.log('Decoded payload:', payload);
var dynamodb = new AWS.DynamoDB();
var dynamodb_params = {
Key: {
dataSource: {
S: payload
}
},
TableName: 'TableName',
AttributesToGet: [
'attribute' // ...
],
ConsistentRead: false,
};
var sns_endpoint = null;
dynamodb.getItem(dynamodb_params, function(err, data) {
if (err) {
console.log(err.stack);
context.done(err, 'Errors while querying dynamodb!');
} else {
console.log(data);
sns_endpoint = data.Item.sns.S;
console.log("Result= " + data);
console.log("Item= " + data.Item);
console.log("sns= " + data.Item.sns);
console.log("value= " + data.Item.sns.S);
console.log("sns_endpoint= " + sns_endpoint);
context.done(null, 'Querying dynamodb succeeded!');
}
});
if( sns_endpoint != null ) {
console.log("sns_endpoint= " + sns_endpoint);
var sns_params = {
Message: payload,
Subject: 'Event Notification From Lambda',
TopicArn: sns_endpoint
};
var sns = new AWS.SNS();
sns.publish(sns_params, function(err, data) {
if (err) {
console.log(err.stack);
context.done(err, 'Errors while putting to SNS!');
} else {
console.log(data);
context.done(null, 'Putting to SNS succeeded!');
}
});
}
});
};
You are calling an asynchronous function, sns.publish(), within a forEach loop. Then you are immediately calling context.succeed(). As soon as context.succeed, context.fail or context.done are called, your Lambda function will exit. You need to modify your code to only call one of those after all asynchronous function calls have completed.