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About how the value is returned using app.set() and app.get()

I am releasing access to pages using connect-roles and loopback but I have a pertinent question about how I can collect the customer's role and through the connect-roles to read the session and respond to a route.
Example, when the client logs in I load a string containing the client's role and access it in a function that controls access to pages.
I have this doubt because I'm finalizing a large scale service that usually there are multiple client sessions that are accessed instantly using a same storage and check function.
It would be efficient to store the customer's role using app.set() and app.get()?
app.get('/session-details', function (req, res) {
var AccessToken = app.models.AccessToken;
AccessToken.findForRequest(req, {}, function (aux, accesstoken) {
// console.log(aux, accesstoken);
if (accesstoken == undefined) {
res.status(401);
res.send({
'Error': 'Unauthorized',
'Message': 'You need to be authenticated to access this endpoint'
});
} else {
var UserModel = app.models.user;
UserModel.findById(accesstoken.userId, function (err, user) {
// console.log(user);
res.status(200);
res.json(user);
// storage employee role
app.set('employeeRole', user.accessLevel);
});
}
});
});
Until that moment everything happens as desired I collect the string loaded with the role of the client and soon after I create a connect-roles function to validate all this.
var dsConfig = require('../datasources.json');
var path = require('path');
module.exports = function (app) {
var User = app.models.user;
var ConnectRoles = require('connect-roles');
const employeeFunction = 'Developer';
var user = new ConnectRoles({
failureHandler: function (req, res, action) {
// optional function to customise code that runs when
// user fails authorisation
var accept = req.headers.accept || '';
res.status(403);
if (~accept.indexOf('ejs')) {
res.send('Access Denied - You don\'t have permission to: ' + action);
} else {
res.render('access-denied', {action: action});
// here
console.log(app.get('employeeRole'));
}
}
});
user.use('authorize access private page', function (req) {
if (employeeFunction === 'Manager') {
return true;
}
});
app.get('/private/page', user.can('authorize access private page'), function (req, res) {
res.render('channel-new');
});
app.use(user.middleware());
};
Look especially at this moment, when I use the
console.log(app.get('employeeRole')); will not I have problems with simultaneous connections?
app.get('/private/page', user.can('authorize access private page'), function (req, res) {
res.render('channel-new');
});
Example client x and y connect at the same time and use the same function to store data about your session?
Being more specific when I print the string in the console.log(app.get('employeeRole')); if correct my doubt, that I have no problem with simultaneous connections I will load a new variable var employeeFunction = app.get('employeeRole'); so yes my function can use the object containing the role of my client in if (employeeFunction === 'Any Role') if the role that is loaded in the string contain the required role the route it frees the page otherwise it uses the callback of failureHandler.
My test environment is limited to this type of test so I hope you help me on this xD

Instead of using app.set you can create a session map(like hashmaps). I have integrated the same in one of my projects and it is working flawlessly. Below is the code for it and how you can access it:
hashmap.js
var hashmapSession = {};
exports.auth = auth = {
set : function(key, value){
hashmapSession[key] = value;
},
get : function(key){
return hashmapSession[key];
},
delete : function(key){
delete hashmapSession[key];
},
all : function(){
return hashmapSession;
}
};
app.js
var hashmap = require('./hashmap');
var testObj = { id : 1, name : "john doe" };
hashmap.auth.set('employeeRole', testObj);
hashmap.auth.get('employeeRole');
hashmap.auth.all();
hashmap.auth.delete('employeeRole');

nodejs does not emit data to client

I have simple nodejs app with sockets and I've faced an error where I can't find any solution. So I'm emiting from app to client and nothing happens there. Or client can't receive it - I don't know, because I can't check if it was successfully emited to client. This is the error I got when I tried to debug callback of emit:
Error: Callbacks are not supported when broadcasting
This my app code:
http.listen(6060, function () {
console.log("Listening on *: 6060");
});
io.set('authorization', function (handshakeData, accept) {
var domain = handshakeData.headers.referer.replace('http://', '').replace('https://', '').split(/[/?#]/)[0];
if ('***' == domain) {
accept(null, true);
} else {
return accept('You must be logged in to take an action in this site!', false);
}
});
io.use(function (sock, next) {
var handshakeData = sock.request;
var userToken = handshakeData._query.key;
if (typeof userToken !== null && userToken !== 0 && userToken !== '0' && userToken.length > 0) {
connection.query('***',
[xssfilter.filter(validator.escape(userToken))],
function (error, data) {
if (error) {
debug('Cant receive user data from database by token');
next(new Error('Failed to parse user data! Please login!'));
} else {
// load data to this user.
_updateUsers(xssfilter.filter(validator.escape(userToken)), 'add', data[0], sock.id);
_loadPreData();
next(null, true);
}
});
} else {
debug('Cant receive user token');
next(new Error('Failed to parse user data! Please login!'));
}
sock.on("disconnect", function () {
_updateUsers(false, 'remove', false, sock.id);
});
});
// we need to show people online count
io.emit('online-count', {
count: Object.keys(connectedUsers).length
});
And the function used above:
function _updateUsers(userToken, action, userData, sockedID) {
switch (action) {
case 'add':
connectedUsers[sockedID] = {...};
io.emit('online-count', io.emit('online-count', {
count: Object.keys(connectedUsers).length
}););
break;
case 'remove':
delete connectedUsers[sockedID];
io.emit('online-count', io.emit('online-count', {
count: Object.keys(connectedUsers).length
}););
break;
}
}
so after emiting online-count I should accept it on the client side as I'm doing it:
var socket;
socket = io(globalData.socketConn, {query: "key=" + globalData.userData.token});
socket.on('connect', function (data) {
console.log('Client side successfully connected with APP.');
});
socket.on('error', function (err) {
error('danger', 'top', err);
});
socket.on('online-count', function (data) {
console.log('Got online count: ' + data.count);
$('#online_count').html(data.count);
});
but the problem is with this online-count.. Nothing happens and it seems that it's not was even sent from node app. Any suggestions?

The problem was with my logic - I was sending online count only if new user were connecting/disconnecting. Problem were solved by adding function to repeat itself every few seconds and send online count to client side.

How do you make multiple database calls from a single connection/transaction with Node.js and Tedious

I am attempting to use NodeJS with the Tedious (http://pekim.github.io/tedious/) sql server plugin to make multiple database calls. My intent is to:
1. Open a connection
2. Start a transaction
3. Make multiple database (stored procedure) calls, which will not return any data.
4. Commit transaction (or roll back on error).
5. Close connection
Here is an example .js file, (without using a transaction) for NodeJS where I am attempting to make multiple database calls and it is failing with the error "Requests can only be made in the LoggedIn state, not the SentClientRequest state." Nothing I try resolves this issue.
Does anyone know how to resolve this?
var Connection = require('tedious').Connection;
var Request = require('tedious').Request;
var config = {
userName: 'login',
password: 'password',
server: '127.0.0.1',
options: { rowCollectionOnDone: true }
};
var max = 1;
for (var i = 0; i < max; i++) {
var connection = new Connection(config);
function executeStatement() {
request = new Request("select 42, 'hello world'", function (err, rowCount) {
if (err) {
console.log(err);
} else {
console.log(rowCount + ' rows');
}
});
request.on('row', function (columns) {
columns.forEach(function (column) {
console.log(column.value);
});
});
request.on('doneInProc', function (rowCount, more, rows) {
});
request.on('doneProc', function (rowCount, more, rows) {
console.log('statement completed!')
connection.execSql(request);
});
request.on('returnStatus', function (status) {
console.log('statement completed!')
});
connection.execSql(request);
}
connection.on('connect', function (err) {
// If no error, then good to go...
executeStatement();
});
}
console.log('Done!');

You're trying to execute a statement on a connection that is not established. You're missing an error handler before you call executeStatement.
connection.on('connect', function (err) {
if (err) {
console.log(err); // replace with your code
return;
};
// If no error, then good to go...
executeStatement();
});
Edit:
How to execute multiple statements in a transaction in serial:
var statements = ["select 1", "select 2", "select 3"];
var transaction = new sql.Transaction(connection);
transaction.begin(function(err) {
// ... error checks
async.mapSeries(statements, function(statement, next) {
var request = new sql.Request(transaction);
request.query(statement, next);
}, function(err, results) {
// ... error checks
transaction.commit(function(err, recordset) {
// ... error checks
console.log("Transaction commited.");
});
});
});

You should use tedious connection pools to create a pool of multiple connections.
For node js, a npm module is available at : https://www.npmjs.com/package/tedious-connection-pool
For every new value inside for loop you can acquire a new connection and use connection.reset on doneInProc event.
The case which you have been doing is performing 1st iteration of for loop correctly(LoggedIn State) and as you have proceeded without closing or releasing the connection you are using same connection object (SentClientRequest state).
Hence the same object is at final state when the code reaches second iteration of for loop.
Hope it resolves your issue

you can use Tedious Connection pools https://github.com/pekim/tedious-connection-pool

As #zevsuld and #mannutech said, tedious-connection-pool will enable multiple connections, and prevent erring out when simultaneous requests come into your server.
Below is a generic example that allows you to write multiple queries within one connection pool, and expose them for use in your api. I'm just adding this in case others come along who are trying to accomplish this type of implementation.
const ConnectionPool = require('tedious-connection-pool');
const path = require('path');
require('dotenv').config({
path: path.join(__dirname, '../../.env')
})
let Request = require('tedious').Request;
let poolConfig = {
min: 10,
max: 50,
log: true
}
let connectionConfig = {
userName: process.env.user,
password: process.env.password,
server: process.env.server
};
//create the pool
let pool = new ConnectionPool(poolConfig, connectionConfig);
pool.on('error', function(err) {
console.error(err);
});
// At this point in the code, we have established a connection pool. If you run node, you'll see it log out all then connections to your database.
// Let's add some methods which your server might use in fulfilling requests to various endpoints.
let query1 = (cb, res, query) => {
// acquire a connection:
pool.acquire(function(err, connection) {
if (err) {
console.error(err);
return;
} else {
// form your query
let sql_query = `SELECT column1, colum2 from TABLE WHERE column1 LIKE '${query.param}%%' ORDER BY column1 ASC`
// use the connection as usual:
request = new Request(sql_query, (err, rowCount) => {
if (err) {
console.log(err);
return;
} else {
// console.log('rowCount:', rowCount);
}
//release the connection back to the pool when finished
connection.release();
});
let records = [];
request.on("row", function(columns) {
let rowArray = [];
columns.forEach(function(column) {
rowArray.push(column.value);
});
records.push(rowArray);
});
request.on("doneInProc", function() {
cb(records, res);
});
// lastly exectue the request on the open connection.
connection.execSql(request);
}
});
};
let query2 = (cb, res, query) => {
// acquire a connection:
pool.acquire(function(err, connection) {
if (err) {
console.error(err);
return;
} else {
// form your query
let sql_query = `SELECT column3, colum4 from TABLE2 WHERE column3 LIKE '${query.param}%%' ORDER BY column3 ASC`;
// use the connection as usual:
request = new Request(sql_query, (err, rowCount) => {
if (err) {
console.log(err);
return;
} else {
// console.log('rowCount:', rowCount);
}
//release the connection back to the pool when finished
connection.release();
});
let records = [];
request.on("row", function(columns) {
let rowArray = [];
columns.forEach(function(column) {
rowArray.push(column.value);
});
records.push(rowArray);
});
request.on("doneInProc", function() {
cb(records, res);
});
// lastly exectue the request on the open connection.
connection.execSql(request);
}
});
};
// Let's expose these two functions to the rest of your API:
module.exports = {
query1,
query2
}

Get return value when using call() with node.js

I am currently programming a socket server in node.js using the json-socket module, and am having some trouble.
Currently when a client connects to the server they send a command in a json object with some data for instance a login would look like this
{ type : 'login', data : { username: 'Spero78' } }
to deal with these requests i have a commands object
var commands = {
'login' : authUser,
'register' : userRegister
}
and these functions are called by server.on
server.on('connection', function(socket) {
console.log('Client Connected');
socket = new JsonSocket(socket);
socket.on('message', function(message) {
if(message.type != undefined) {
if(commands[message.type]){
var response = commands[message.type].call(this, message.data);
if(response != undefined){
console.log(response);
socket.sendMessage(response);
} else {
console.log("No Response!");
}
} else {
console.log('Unexpected Command!');
}
}
});
});
The functions return javascript objects but the response var is always undefined and the "No Response!" message is always printed
Here is the authUser function
function authUser(data){
console.log('Auth: ' + data.username);
database.query('SELECT * FROM players WHERE username = ?', [data.username], function(err, results) {
if(results.length < 1){
console.log('Bad Login!');
var response = {
type : 'badlogin',
data : {
//...
}
}
return response;
}
var player = results[0];
var response = {
type : 'player',
data : {
//...
}
}
return response;
});
}
Is there a better way of doing this? or am i missing something that is causing the objects to not return

database.query() is asynchronous, so when you call this function, nodejs don't wait the response of the callback to go to next instruction.
So the value tested on your condition is not the return in the callback, but of the whole authUser function, that's why it's always undefined.
You probably need tor refactor your code.

Redis connection close

Im using connect-domain and connect-redis. Below code checks for redis cache in Redis database.
function redis_get(key, req, res) {
var redisClient = redis.createClient();
redisClient.get(redisKey, function (err, data) {
if (err) {
console.log("Error in RedisDB");
}
else if (data == null) {
// Calling external function
}
else {
// Calling external function
}
redisClient.quit(); // Not working
});
}
When cache is not avaiable Im calling external function. I want redis connection to be closed once the cache check has been done.
redisClient.quit() // Not working
Any help on this will be really helpful.
Thanks

Below code is working fine without any problem.So check your status reply in the quit method if you get status as 'OK' means that method is working fine.
var redis=require('redis');
var redisClient = redis.createClient();
redisClient.get('name', function (err, data) {
if (err) {
console.log("Error in RedisDB");
}
else if (data == null) {
console.log('null');
}
else {
console.log(data);
}
redisClient.quit(redis.print);
});