I am trying to implement multiple data insertion on one call and trigger response only after all data is inserted. This is how I am currently doing it:
create: function(req, res) {
var response = {};
var num = req.body.num;
var ret = 0;
for (var i = 0; i < num; i++) {
var db = new user();
db.enabled = false;
db.save(function(err){
if(err) {
// Handle error
} else {
ret++;
// Do something
}
});
}
response = {"status" : 200, "message" : "It's working: " + ret};
res.json(response);
}
The problem with this approach is that all the callbacks for save will be triggered after res.json(response) which is wrong because sometimes I would also like to inform user how much data was saved. User will always receive the following response:
It's working: 0
Because ret variable is always 0. It's getting increased only after response is already triggered. What am I doing wrong?
EDIT:
Code after Will's suggestion:
var Q = require('q');
create: function(req, res) {
var response = {};
var num = req.body.num;
var ret = 0;
var tasks = [];
for (var i = 0; i < num; i++) {
var db = new user();
db.enabled = false;
tasks.push(db.save());
}
Q.all(tasks).then(
function(results) {
response = {"status" : 200, "message" : "It's working!"};
},
function(err) {
response = {"status" : 500, "message" : "Not working!" };
);
res.json(response);
}
for (var i = 0; i < num; i++) {
var db = new user();
db.enabled = false;
db.save(function(err){
if(err) {
// Handle error
} else {
ret++;
if(ret == num){
response = {"status" : 200, "message" : "It's working: " + ret};
res.json(response);
}
}
});
}
Related
I'm trying to get the first 5 pages of search results with google custom search API ...
So far I've tried to achieve the result using nested function but with no luck.
I know that I'm messing with callback but, so far I've not figure out the correct way (without using promises library) to solve my problem.
Could some of you point me out in the right direction?
Thanks.
app.get('/assesment', function(req, res){
console.log('route: /assesment');
var api_key = '';
var customsearch = google.customsearch('v1');
var response = "";
var number_of_pages = 5;
var next_page = 1;
var exit = 0
const CX = 'XXXXX';
const API_KEY = 'XXXXX';
const SEARCH = 'Test Query';
console.log('start');
// console.log('QUERY PAGE: '+pages);
doSearch(CX, SEARCH, API_KEY, next_page, function(resp){
res.send(resp);
});
//
// Functions
//
function doSearch(_cx, _search, _api_key, _start, callback ){
var response = '';
customsearch.cse.list({ cx: _cx, q: _search, auth: _api_key, start: _start }, function (err, resp) {
if (err) {
response = JSON.stringify(err);
} else {
// Got the response from custom search
console.log('Result: ' + resp.searchInformation.formattedTotalResults);
if (resp.items && resp.items.length > 0) {
console.log('First result of '+resp.items.length+' is ' + resp.items[0].title);
for (var i = 0; i < resp.items.length; i++) {
response += resp.items[i].title+"<br>";
response += resp.items[i].link +"<br><hr>";
}
}
res = {
response: response,
next_page: resp.queries.nextPage
}
// res =
}
_start += 1;
if (_start < 6 ) {
doSearch(_cx, _search, _api_key, _start, _start*10+1,
function(resp){
response += resp;
});
}
if (callback && typeof callback === "function") callback(response);
});
};
});
You can use a third-party service like SerpApi to scrape Google and get back structured JSON.
Example using the Node.js library to get 4 page of results:
var gsr = require('GoogleSearchResults')
let serp = new gsr.GoogleSearchResults("demo")
serp.json({
q: "Coffee",
num: 10,
start: 30,
location: "Portland"
}, (result) => {
console.log(result)
})
I am facing problem when I try to invoke SQL resultSet for second time, and I get error Cannot read property "resultSet" from undefined. so I just wondering how to reuse resultSetor call multiple resultSet.
Main.js
function getAuthen(){
var username = $("#AuthUsername").val();
var password = $("#AuthPassword").val();
var invocationData = {
adapter: "ConnectDB",
procedure : 'getauthentication',
parameters : [username, password]
};
WL.Client.invokeProcedure(invocationData, {
onSuccess : getAuthenSuccess,
onFailure : getAuthenFailure
});
}
function getAuthenSuccess(result){
if(result.invocationResult.resultSet.length > 0)
{
$("#AuthDiv").hide();
$("#header_main").show();
$("#Menu").show()
$('#DisplayName').html(result.invocationResult.resultSet[0].NME);
$('#DisplaySurname').html(result.invocationResult.resultSet[0].SURNME);
} else {
getAuthenFailure();
}
}
function getAuthenFailure(result){
var alertTitle = "Fail to Login";
var alertText = "Please Enter Username and Password Correctly";
WL.SimpleDialog.show(alertTitle, alertText,[
{
text : 'OK',
handler : getLogout
}
]);
}
//***************************** END ************************\\
//*********** Get Problem On Going ************************//
function queryProblemOnGoing(){
var invocationDataP = {
adapter: "ConnectDB",
procedure : 'getproblemOngoing',
parameters : []
};
WL.Client.invokeProcedure(invocationDataP, {
onSuccess : getProblemOnGoingSuccess,
onFailure : getProblemOnGoingFailure
});
}
function getProblemOnGoingSuccess(result){
if(result.invocationResult.resultSet.length > 0)
{
window.alert("Success");
$("#Menu").show()
// displayQueryOnGoing(result.invocationResult.resultSet);
} else {
window.alert("Fail");
//getProblemOnGoingFailure();
}
}
function getProblemOnGoingFailure(result){
var alertTitle = "Fail to Retrive Data";
var alertText = "Please Contact Administrator";
WL.SimpleDialog.show(alertTitle, alertText,[
{
text : 'OK'
}
]);
}
function displayQueryOnGoing(result) {
for (var i =0; i < result.length; i++)
{
$('#problemOnGoingTable').append("<tr><td>" + result[i].CALLNO + "</td></tr>");
$('#problemOnGoingTable').append("<tr><td>" + result[i].CALLNOREF + "</td></tr>");
}
}
ConnectDB Adapter
var AuthenStatement = WL.Server.createSQLStatement("select NME, SURNME, CUS_ID from USERS where USERID = ? AND PASSWD = ?");
var problemOngoingStatement = WL.Server.createSQLStatement("select * from CALL”);
function getauthentication(userid, password) {
return WL.Server.invokeSQLStatement({
preparedStatement : AuthenStatement,
parameters : [userid, password]
});
}
function getproblemOngoing() {
return WL.Server.invokeSQLStatement({
preparedStatement : problemOngoingStatement,
parameters : []
});
}
I am not really sure how it is working the first time, or which part is working on the first time.
Anyway, I suspect that the problem is here:
for (var i =0; i < result.length; i++)
Perhaps you should change result.length to result.invocationResult.resultSet.length.
I recently posted an issue I had with another Parse CloudCode method, were the error was thrown that Error: success/error was not called. I am having that issue again but with a different method/scenario.
Parse.Cloud.define("background", function(request, response) {
var moments = require("cloud/moments.js");
var now = moments.moment();
var query = new Parse.Query("Group");
query.find({
success: function(results) {
for (var i = 0; i < results.length; i++) {
var object = results[i];
var events = object.get("Events");
var getUsers = false;
for (var q = 0; q < events.length; q++) {
var e = events[q];
if (e.get("date") == now) {
getUsers = true;
break;
}
}
if (getUsers == true) {
for (var q = 0; q < events.length; q++) {
var e = events[q];
if (e.get("date") == now) {
var relation = object.relation("created");
var partOne = e.get("name");
var outString1 = partOne.concat(" is now");
// generate a query based on that relation
var query = relation.query();
Parse.Push.send({
where: query, // Set our Installation query
data: {
alert: outString1
}
}, {
success: function() {
// Push was successful
},
error: function(error) {
// Handle error
}
});
var relation2 = object.relation("joined");
var partOnee = e.get("name");
var outString = partOnee.concat(" is now");
// generate a query based on that relation
var query2 = relation.query();
Parse.Push.send({
where: query2, // Set our Installation query
data: {
alert: outString
}
}, {
success: function() {
// Push was successful
},
error: function(error) {
// Handle error
}
});
e.destroy();
}
}
}
}
}
});
response.success();
});
Since this method involves more than just a simple query and return (as it has the for loop among other things) I am a bit confused on how to implement the Parse Promise stuff. If anyone could assist me in how I should go about implementing the promise stuff it would be much appreciated.
Parse documentation is very clear on how to use Promises and how to rewrite your pyramid code with .then() blocks instead.
So this will be a lot of code, but what matter is on line 22-25, and line 87-91. The rest of the code works. I have a nested function and want to return the JSON string. Using console.log I can tell it is running properly but will not return the JSON string. Look for the part that says //---------this part-------. There are two parts that I am asking about.
exports.post = function(request, response) {
var mssql = request.service.mssql;
//var data = '{"userID":"ryan3030#vt.edu1"}';
var inputJSON = request.body.JSONtext;
var json = JSON.parse(inputJSON);
var userID = json.userID;
mssql.query("EXEC getMeetingInfo ?", [userID],
{
success: function(results3) {
var meetingsToday = results3.length;
var meetingID = results3[0].meetingID;
var meetingName = results3[0].meetingName;
var meetingDescription = results3[0].meetingDescription;
var meetingLength = results3[0].meetingLength;
var meetingNotes = results3[0].meetingNotes;
var hostUserID = results3[0].hostUserID;
//--------------------------------------THIS PART------------------------------
var JSONfinal = allInfoFunction(mssql, meetingID, userID, meetingName, meetingDescription, meetingLength, meetingNotes, hostUserID, meetingsToday);
console.log(JSONfinal);//DOES NOT WORk
response.send(statusCodes.OK, JSONfinal);//DOES NOT WORK
//---------------------------------BETWEEN THESE----------------------------------
},
error: function(err) {
console.log("error is: " + err);
response.send(statusCodes.OK, { message : err });
}
});
};
function allInfoFunction(mssql, meetingID, userID, meetingName, meetingDescription, meetingLength, meetingNotes, hostUserID, meetingsToday){
mssql.query("EXEC getLocation ?", [meetingID],
{ success: function(results2) {
var meetingLocation = results2[0].meetingLocation;
var JSONlocation = {"meetingLocation": meetingLocation};
mssql.query("EXEC getDateTime ?", [meetingID],
{ success: function(results1) {
var length = results1.length;
var dateTime = [];
dateTime[0] = results1[0].meetingDateTime;
for (var x= 1; x < length; x++) {
dateTime[x] = results1[x].meetingDateTime;
}
//console.log(dateTime);
mssql.query("EXEC getDateTimeVote",
{ success: function(results) {
//console.log(results);
var JSONoutput2 = {};
var JSONtemp = [];
var length2 = results.length;
for(var j = 0; j < length; j++){
var vote = false;
var counter = 0;
for(var z = 0; z < length2; z++){
var a = new Date(results[z].meetingDateTime);
var b = new Date(results1[j].meetingDateTime);
if(a.getTime() === b.getTime()){
counter = counter + 1;
}
if((a.getTime() === b.getTime()) && (results[z].userID == userID)){
vote = true;
}
}
var meetingTimeInput = {"time": b, "numVotes": counter, "vote": vote}
JSONtemp.push(meetingTimeInput);
JSONoutput2.meetingTime = JSONtemp;
}
var JSONfinal = {};
var mainInfoArray = [];
var JSONmainInfo = {meetingID: meetingID, meetingName: meetingName, meetingDescription: meetingDescription, meetingLength: meetingLength, meetingNotes: meetingNotes, hostUserID: hostUserID, meetingLocation: meetingLocation };
JSONmainInfo.meetingTime = JSONtemp;
JSONfinal.numMeetingsToday = meetingsToday;
mainInfoArray.push(JSONmainInfo);
JSONfinal.meetingList = mainInfoArray;
//response.send(statusCodes.OK, JSONfinal);
//---------------------------------------AND THIS PART-------------------------------
console.log(JSON.stringify(JSONfinal));//This outputs the correct thing
var lastOne = JSON.stringify(JSONfinal);
return lastOne; //ths dosent work
//-------------------------------------BETWEEN THESE-----------------------------------
},
error: function(err) {
console.log("error is: " + err);
//response.send(statusCodes.OK, { message : err });
}
});
},
error: function(err) {
console.log("error is: " + err);
//response.send(statusCodes.OK, { message : err });
}
});
},
error: function(err) {
console.log("error is: " + err);
//response.send(statusCodes.OK, { message : err });
}
});
}
I've done a little refactoring to your code to take a more modular approach. It becomes quite tricky to debug something like what you have above. Here it is:
exports.post = function(request, response) {
var mssql = request.service.mssql;
var inputJSON = request.body.JSONtext;
var json = JSON.parse(inputJSON);
var userID = json.userID;
var JSONFinal = {};
getMeetingInfo(userID);
function getMeetingInfo(userID){
mssql.query("EXEC getMeetingInfo ?", [userID], {
success: function(results){
JSONFinal.meetingsToday = results.length;
JSONFinal.meetingID = results[0].meetingID;
JSONFinal.meetingName = results[0].meetingName;
JSONFinal.meetingDescription = results[0].meetingDescription;
JSONFinal.meetingLength = results[0].meetingLength;
JSONFinal.meetingNotes = results[0].meetingNotes;
JSONFinal.hostUserID = results[0].hostUserID;
// Call next function
getLocation(JSONFinal);
},
error: function(err) {
console.log("error is: " + err);
response.send(statusCodes.OK, { message : err });
}
});
}
function getLocation(){
mssql.query("EXEC getLocation ?", [JSONFinal.meetingID], {
success: function(results) {
JSONFinal.meetingLocation = results[0].meetingLocation;
// Call next function
getDateTime(JSONFinal);
},
error: function(err) {
console.log("error is: " + err);
}
});
}
function getDateTime(){
mssql.query("EXEC getDateTime ?", [JSONFinal.meetingID], {
success: function(results) {
var length = results.length;
var dateTime = [];
for (var x= 0; x < length; x++) {
dateTime[x] = results[x].meetingDateTime;
}
// Call next function
getDateTimeVote(dateTime);
},
error: function(err){
console.log("error is: " + err);
}
});
}
function getDateTimeVote(dateTime){
mssql.query("EXEC getDateTimeVote", {
success: function(results) {
var JSONtemp = [];
var length2 = results.length;
for(var j = 0; j < dateTime.length; j++){
var vote = false;
var counter = 0;
for(var z = 0; z < length2; z++){
var a = new Date(results[z].meetingDateTime);
var b = new Date(results1[j].meetingDateTime);
if(a.getTime() === b.getTime()){
counter = counter + 1;
}
if((a.getTime() === b.getTime()) && (results[z].userID == userID)){
vote = true;
}
}
var meetingTimeInput = {"time": b, "numVotes": counter, "vote": vote}
JSONtemp.push(meetingTimeInput);
}
var JSONmainInfo = {
meetingID: JSONFinal.meetingID,
meetingName: JSONFinal.meetingName,
meetingDescription: JSONFinal.meetingDescription,
meetingLength: JSONFinal.meetingLength,
meetingNotes: JSONFinal.meetingNotes,
hostUserID: JSONFinal.hostUserID,
meetingLocation: JSONFinal.meetingLocation
meetingTime: JSONtemp
};
var JSONfinal = {
numMeetingsToday: JSONFinal.meetingsToday,
meetingsList: [JSONmainInfo]
};
// Call next function
sendResponse(JSON.stringify(JSONfinal));
},
error: function(err) {
console.log("error is: " + err);
}
});
}
function sendResponse(data){
response.send(statusCodes.OK, data);
}
};
It looks a lot different but the functionality is pretty much the same. The key point if you look at the code is that each subsequent function is executed only after the success of the previous function. This effectively chains the methods together so that they are always executed in order and is the key point of difference.
One thing to note here is the similarity between your
allInfoFunction(...
and my
getMeetingInfo(userID)
Both of these will return undefined more or less immediately, after the MSSQL query is sent to the server. This is because the request is fired asynchronously, and the javascript continues to run through the code. After it's fired of the asynchronous request, it has nothing left to do in that function, so it returns. There is no return value specified so it returns nothing (or undefined if you will).
So all in all, the code in the question code will return undefined and then attempt to send a response before anything has actually happened. This code fixes that problem by firing the sendResponse after all the queries have been executed.
I refactored this code in a text editor and haven't run it, or checked it for errors, so follow the basic outline all you like but it may not be a good idea to copy and paste it without checking it's not broken
So at my server app when I get a socket request I send data based on what user is requesting the information...
server.on('connection', function(socket) {
socket.on('login', function(data) {
connection.query('SELECT * FROM users WHERE name = ? AND password = ? LIMIT 1', [data.name, data.password], function(err, result) {
if(result.length === 0)
{
socket.emit('login-failed');
}
else
{
if(users.check(result[0].name))
{
result[0].socket = socket.id;
users.add(result[0]);
console.log(colors.yellow('User: ' + result[0].name + ' connected.'));
socket.emit('login-success');
}
}
});
});
So when a user logs in I save some information like username, password, socketid.
var userList = [];
exports.add = function(data)
{
userList.push(data);
}
exports.check = function(data)
{
for(var i = 0; i < userList.length; i++)
{
if(userList[i].name === data)
{
return false;
}
}
return true;
}
exports.remove = function(id)
{
for(var i = 0; i < userList.length; i++)
{
if(userList[i].socket === id)
{
var index = userList.indexOf(i);
userList.splice(index, 1);
return true;
}
}
return false;
}
So as you can see Im saving users data that I will access later for example on here
socket.on('test', function(data) {
if(users.remove(socket.id)) console.log('Yes');
});
But the only way I have to identify a socket is by using its socket.id, now my question is if I can really trust socketid or if I should use another 'system' to actually manage my users logic.
I cant really figure any other system to actually check what socket is calling my server