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Async call in javascript For Loop not working

I have a callback function inside a loop here for (var res in results) {
but it seems the loop is not waiting for the async call. When I am calling self.callTestOutputData(test_output_url) here, the loop is not waiting fpor the response but continuing for the next iteration and I am losing out the value to push into obj.requistion_number = testOutputResponse.value;
Please note : var results = response.results Here results is an array of Json objects.
Edit 1 : I tried forEach but that didn't work .
results.forEach(res => {
var obj = {}
obj.ferp = res.name;
// your code...
})
Original Code:
self.downloadDailyExcelProcurement = function (filters, excelTmpArr) {
self.disableExcelDownloadProcurement(true);
$('.useCaseExcelButtonProcurement .oj-button-button .oj-button-label')[0].style.backgroundColor = "gray";
$('.useCaseExcelButtonProcurement .oj-button-button .oj-button-label .demo-download-icon-24')[0].style.color = "#D8D8D8";
var payload = {};
if (typeof filters === "string") {
var fill = filters;
} else {
var fill = self.sendFilters();
if(self.app() === "fusion"){
fill += '&module=Procurement';
}else if (self.app() === "o2r"){
fill += '&module=O2r';
}
}
if(fill.includes("%3A")){
fill = fill.replace(/%3A/g, ':');
}
payload.Endpoint = 'executions/testcollection/' + fill;
//console.log(payload.Endpoint)
payload.BeforeSend = function (xhr) {
xhr.setRequestHeader('Authorization', 'Basic ' + btoa('guest:oracle123'));
$(".custom-loader-circle").show();
};
payload.OnSuccess = function (response) {
var results = response.results;
for (var res in results) {
var obj = {}
obj.ferp = results[res].name;
obj.po = "NA"
obj.receipt_no = "NA"
var test_output_url = results[res].reference_test_cases[0].automation_tests[0].test_outputs[0]
$.when(self.callTestOutputData(test_output_url)).done(function (testOutputResponse) {
if(testOutputResponse)
obj.requistion_number = testOutputResponse.value;
else {
obj.requistion_number = "NA";
}
self.excelTmpArr().push(obj);
});
}
else {
self.excelTmpArr().push(obj);
}
}
if (response.next) {
filters = ((response.next).split('testcollection'))[1];
if (filters[0] === "/") {
var test = filters.slice(1, filters.length);
}
self.downloadDailyExcelProcurement(test, self.excelTmpArr());
} else {
if (results.length === 0) {
$(".custom-loader-circle").hide();
self.disableExcelDownloadProcurement(false);
$('.useCaseExcelButtonProcurement .oj-button-button .oj-button-label')[0].style.backgroundColor = "#4d0000";
$('.useCaseExcelButtonProcurement .oj-button-button .oj-button-label .demo-download-icon-24')[0].style.color = "white";
showMessage(self.messages, "No Data to Download", '', 'info');
} else {
self.formatForExcel(self.excelTmpArr(), fill, "Procurement");
}
}
};
payload.OnError = function (data) {
showMessage(self.messages, data.status, data.statusText, 'error');
$(".custom-loader-circle").hide();
};
getData(payload);
}

Try using async and await :
async function asyncCall () {
// call here
}
for (var res in results) {
const response = await asyncCall();
}

var results = response.results;
if(result.length > 0){
results.map((data,index)=>{
//write your code here
})
}
This will help you ..

Use forEach() to iterate since it creates its own function closure:
results.forEach(res => {
var obj = {}
obj.ferp = res.name;
// your code...
})

CosmosDb Stored procedure There Is An error In My Javascript

There is an error in my Javascript but I just can't understand why. In the code below when the function
function replaceDoc(document,callback)
is called the document is null. I have checked that there are documents in the feed from
function tryQuery(callback) {...
and there is some kind of error. The procedure runs fine and response body shows this. Where is my mistake please?
function bulkChangeJobNumber(docs) {
var collection = getContext().getCollection();
var collectionLink = collection.getSelfLink();
var response = getContext().getResponse();
var responseBody = {
docsRetrieved: 0,
msg:'',
msg2:''
}
var docs;
var count = 0;
//get the docs
tryQuery(callback);
function tryQuery(callback) {
var isAccepted = collection.queryDocuments(
collection.getSelfLink(),
"SELECT * FROM c WHERE c.ty = 'job' AND NOT IS_DEFINED(c.jobNumber)", function (err, feed, options) {
if (err) throw err;
// Check the feed and if empty, set the body to 'no docs found',
// else take 1st element from feed
docs = feed;
responseBody.docsRetrieved = docs.length;
responseBody.msg = options;
responseBody.msg2 = docs[0];
if (feed.length == 0) {
response.setBody("No Docs");
}
else{
replaceDoc(docs[count],callback);
}
});
if (!isAccepted) {
response.setBody("The query was not accepted!");
return;
}
}
function replaceDoc(document,callback){
if(document == null){
responseBody.msg = "document is null";
response.setBody(responseBody);
return;
}
document.jobNumber = document.jobId;
var accept = collection.replaceDocument(document._self,document, callback);
if(!accept){
response.setBody(`Processed: ${count} docs`);
}
}
function callback(err,doc,options){
if (err) throw err;
count++;
if(count > docs.length){
response.setBody(`processed all ${count} docs`)
}else{
replaceDoc(docs[count],callback);
}
}
}

How can I return a value from a function after closing the Oracle DB connection inside nodejs program

Here is what I am trying. In last I am returning the account number so that I can use it in another function but it seems like the value should be returned before closing the connection, or by any different approach. Can you please help me to identify what can be changed here so that I can utilize the returned value.
PS: It's a Nodejs program, using Oracle DB connection.
function getShipmentData(shipment){
var defer = q.defer();
var tnt_account_number;
var account_number;
var dhl_account_number;
var place_to_bil;
var freight_terms_shp;
var place_to_repair;
var shipment_id;
oracledb.outFormat = oracledb.OBJECT;
console.log("before getConnection")
oracledb.getConnection(
{
user : settings.ora_db_user,
password : settings.ora_db_password,
connectString : settings.ora_db_host+':'+settings.ora_db_port+'/'+settings.ora_db_service
},
function(err, connection)
{
console.log("After getConnection")
if (err) {
writeDebug({'error':err.message});
defer.reject(err);
}
const shipment_sql = `select r.PLACE_ID_TO_BILL as Place_TO_BILL, s.freight_terms_shp as Freight_Terms,
r.PLACE_ID_SHIP_TO as Place_To_Repair, s.shipment_id as Shipment_ID
from shipment s inner join request r on s.request_id = r.request_id
where s.shipment_id = :SHIPMENT_ID`
var bindVars = {
SHIPMENT_ID: shipment
};
connection.execute(
shipment_sql,
bindVars,
function(err, result)
{
var row;
if (err) {
console.log("Error:", err)
connection.close();
defer.reject(err);
}
var results = result.rows
Object.keys(results).forEach(function(key){
row = results[key];
place_to_bil = row.PLACE_TO_BILL
freight_terms_shp = row.FREIGHT_TERMS
place_to_repair = row.PLACE_TO_REPAIR
shipment_id = row.SHIPMENT_ID
console.log("place_to_bil from Data:",place_to_bil);
console.log("freight_terms from Data:",freight_terms_shp);
console.log("place_to_repair from Data:",place_to_repair);
console.log("shipment_id from Data:",shipment_id);
})
function getAccountNumber(){
if(freight_terms_shp == 'ABHTC') {
if(place_to_repair == 'MYTPIC-401' && place_to_bil == 'GTHBYR-001')
tnt_account_number = '8934734';
else if (place_to_repair == 'CNHBNT-40000' && place_to_bil == 'CBCINF-001') {
tnt_account_number = '3489523';
}
else tnt_account_number = '5438648';
}
return tnt_account_number;
}
account_number = getAccountNumber();
console.log("TNT Account Number before closing connection:", account_number)
connection.close();
console.log("TNT Account Number after closing connection:", account_number)
defer.resolve(result.rows);
});
});
console.log("Account Number getting returned?", account_number);
return account_number;
}

How to maintain Timeout Session when calling Api Call in Loop Contion

i having Api Call which execute in For Loop some of the value which returns 10 sec itself some may take nearly 60 sec i have to maintain proper Timeout and clear session (i.e if results comes at 15 sec means it should goes to next input values and run the code) but currenly its waiting for 45 sec each single record how to optimize it
here my sample code :
if (selectedrows.length >= 1) {
for (var i = 0; i < selectedrows.length; i++) {
var myVar = setTimeout (function (k) {
var ob = { results: "Appending ..." };
child.update(selectedrows[k][4], selectedrows[k][4], ob);
var fullName = selectedrows[k][1] + ' ' + selectedrows[k][2];
math.ResultCall.async(fullName,function (err, res) {
if (err) throw err;
var returnedValue = JSON.parse(res);
console.log(returnedValue);
if(returnedValue.Result == null || returnedValue.Result.FOUND_Result == null)
{
console.log("None found")
}
else{
var obj = { results: “res” };
child.update(selectedrows[k][4], selectedrows[k][4], obj);
}
}
});
}, i * 45000,i);
}
}

Rephrasing your question, you need to return the data when your api gets resolved.
For this please go through https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Promise/resolve
JavaScript, by default it work asynchronously because of its event loop.
You have promises and resolve to get notified when your api returns a data
Hope I helped :)

There are several approaches to implement the solution
1. Async-Await: in-case the records-processing order is important
for( let i=0; i<selectedrows.length; i++)
{
let ob = { results: "Appending ..." };
child.update(selectedrows[i][4], selectedrows[i][4], ob);
let fullName = selectedrows[i][1] + ' ' + selectedrows[i][2];
await new Promise((resolve,reject)=>
{
math.ResultCall.async(fullName,(err, res) => {
if (err) reject(err);
let returnedValue = JSON.parse(res);
console.log(returnedValue);
if(returnedValue.Result == null || returnedValue.Result.FOUND_Result == null) {
console.log("None found")
} else {
let obj = { results: “res” };
child.update(selectedrows[i][4], selectedrows[i][4], obj);
}
resolve();
});
}
**don't forget this means the wrapping function should be async as well (which returns a promise that can be resolved if necessary)
2.Promise.All: if the order is not important
let promArray = [];
for( let i=0; i<selectedrows.length; i++)
{
let ob = { results: "Appending ..." };
child.update(selectedrows[i][4], selectedrows[i][4], ob);
let fullName = selectedrows[i][1] + ' ' + selectedrows[i][2];
promArray.push( new Promise((resolve,reject)=>
{
math.ResultCall.async(fullName,(err, res) => {
if (err) reject(err);
let returnedValue = JSON.parse(res);
console.log(returnedValue);
if(returnedValue.Result == null || returnedValue.Result.FOUND_Result == null) {
console.log("None found")
} else {
let obj = { results: “res” };
child.update(selectedrows[i][4], selectedrows[i][4], obj);
}
resolve();
});
);
}
Promise.all(promArray);
** this will also return a Promise that can be resolved if necessary.

How to callback an error message when searching a table is unsuccessful in DynamoDB

I'm currently using AWS Lambda JavaScript code to try and search a DynamoDB table this is then implemented into an Amazon Alexa application, but that isn't really important for what I'm asking. Here is the code I'm struggling with:
function readDynamoItem(params2, callback) {
var AWS = require('aws-sdk');
AWS.config.update({region: AWSregion});
var dynamodb = new AWS.DynamoDB();
console.log('reading item from DynamoDB table');
dynamodb.scan(params2, function (err, data){
if (err) {
callback("error");
//console.log(err, err.stack); // an error occurred
}
else{
callback(data);
}
});
}
So when an error occurs I want it to callback the message "error" and then use it here:
const params2 = {
TableName: 'Fixtures',
FilterExpression: 'team1 = :value',
ExpressionAttributeValues: {':value': {"S": MyQuestion.toLowerCase()}}
};
readDynamoItem(params2, myResult=>{
say = myResult;
this.response.speak(say).listen('try again');
this.emit(':responseReady');
});
All I'm getting at the moment is this response when I test, I think due to err just ending the program instead of calling the error back to use in the implementation:
Response:
{
"errorMessage": "RequestId: 0f586880-2ddb-11e8-bdf7-07b4c224b25d Process exited before completing request"
}
Any help would be greatly appreciated.
Here's the full code for my project for further reference:
const AWSregion = 'eu-west-1';
const Alexa = require('alexa-sdk');
const AWS = require('aws-sdk');
AWS.config.update({
region: AWSregion
});
exports.handler = function(event, context, callback) {
var alexa = Alexa.handler(event, context);
// alexa.appId = 'amzn1.echo-sdk-ams.app.1234';
// alexa.dynamoDBTableName = 'YourTableName'; // creates new table for session.attributes
alexa.registerHandlers(handlers);
alexa.execute();
};
const handlers = {
'LaunchRequest': function () {
this.response.speak('welcome to magic answers. ask me a yes or no question.').listen('try again');
this.emit(':responseReady');
},
'MyIntent': function () {
var MyQuestion = this.event.request.intent.slots.MyQuestion.value;
console.log('MyQuestion : ' + MyQuestion);
const params2 = {
TableName: 'Fixtures',
FilterExpression: 'team1 = :value',
ExpressionAttributeValues: {':value': {"S": MyQuestion.toLowerCase()}}
};
const params3 = {
TableName: 'Fixtures',
FilterExpression: 'team2 = :value',
ExpressionAttributeValues: {':value': {"S": MyQuestion.toLowerCase()}}
};
readDynamoItem(params2, myResult=>{
var say = MyQuestion;
//if nothing is found when scanning for team1, scan team2
if (myResult == "error"){
readDynamoItem(params3, myResult2=>{
say = myResult2;
say = 'The top scorer for ' + MyQuestion + ' is ' + myResult2;
this.response.speak(say).listen('try again');
this.emit(':responseReady');
});
}
else{
say = myResult;
say = 'The top scorer for ' + MyQuestion + ' is ' + myResult;
this.response.speak(say).listen('try again');
this.emit(':responseReady');
}
});
},
'AMAZON.HelpIntent': function () {
this.response.speak('ask me a yes or no question.').listen('try again');
this.emit(':responseReady');
},
'AMAZON.CancelIntent': function () {
this.response.speak('Goodbye!');
this.emit(':responseReady');
},
'AMAZON.StopIntent': function () {
this.response.speak('Goodbye!');
this.emit(':responseReady');
}
};
// END of Intent Handlers {} ========================================================================================
// Helper Function =================================================================================================
//reading the Fixtures table
function readDynamoItem(params2, callback) {
var AWS = require('aws-sdk');
AWS.config.update({region: AWSregion});
var dynamodb = new AWS.DynamoDB();
var team1;
var team2;
console.log('reading item from DynamoDB table');
dynamodb.scan(params2, function (err, data){
if (err) {
callback("error");
//callback("error");
//console.log(err, err.stack); // an error occurred
}
else{
console.log(data); // successful response
team1 = jsonToString(data.Items[0].team1);
team2 = jsonToString(data.Items[0].team2);
var t1goals = jsonToString(data.Items[0].t1goals);
var t2goals = jsonToString(data.Items[0].t2goals);
t1goals = parseInt(t1goals);
t2goals = parseInt(t2goals);
var search;
var chosenValue = Math.random() < 0.5 ? team1 : team2;
// if goals are equal in a match then it is random which team will score next
if(t1goals == t2goals){
search = chosenValue;
}
//if a team has 1 goal more than the other then it is a 3rd more likely they will score next
else if(t1goals > t2goals && t1goals == 1){
if(randomInt(1, 3) == 1){
search = team2;
}
else{
search = team1;
}
}
else if(t2goals > t1goals && t2goals == 1){
if(randomInt(1, 3) == 1){
search = team1;
}
else{
search = team2;
}
}
//if a team has more than 1 goal more than the other then it is a 5th more likely they will score next
else if(t1goals > t2goals && t1goals > 1){
if(randomInt(1, 5) == 1){
search = team2;
}
else{
search = team1;
}
}
else if(t2goals > t1goals && t2goals > 1){
if(randomInt(1, 5) == 1){
search = team1;
}
else{
search = team2;
}
}
var params = {
TableName: 'yesno',
FilterExpression: 'team = :value',
ExpressionAttributeValues: {':value': {"S": search}}
};
readDynamoFixtures(params, myResult=>{
callback(myResult);
});
}
});
}
//read player details from the the yesno table
function readDynamoFixtures(params, callback) {
var goals = new Array();
var playing = new Array();
var messages = new Array();
var most = 0;
var mostMessage;
var dynamodb = new AWS.DynamoDB();
dynamodb.scan(params, function (err, data) {
if (err) console.log(err, err.stack); // an error occurred
else{
for(var i = 0; i <= (data.Count - 1); i++){
console.log(data); // successful response
var temp = jsonToString(data.Items[i].playername);
messages[i] = temp;
temp = jsonToString(data.Items[i].goals);
temp = parseInt(temp);
goals[i] = temp;
temp = jsonToString(data.Items[i].playing);
playing[i] = temp;
//compare each players goals
if (goals[i] > most && playing[i] == "true"){
most = goals[i];
mostMessage = messages[i];
}
}
}
callback(mostMessage);
});
}
//convert database items from json format to string
function jsonToString(str){
str = JSON.stringify(str);
str = str.replace('{\"S\":\"', '');
str = str.replace('\"}', '');
return str;
}
//get a random int between min and max
function randomInt(min,max)
{
return Math.floor(Math.random()*(max-min+1)+min);
}
Edit:
I have tried testing this code with .query instead of .scan and the error callback works perfectly which is strange but obviously for this implementation I need to use .scan

When you get the "Process exited" response from the Lambda it is helpful to log heavily to see where the Lambda is getting stuck and then check the Cloudwatch Logs to get to the detail.
Then you can pinpoint the exception and focus on it. At least for me, the root cause was many times unexpected as Lambdas force a different way of thinking.