Express perform a function before responding - node.js

var express = require('express');
var app = express();
var bodyParser = require('body-parser');
app.use(bodyParser.urlencoded({ extended: true }));
app.use(bodyParser.json());
var port = process.env.PORT || 8080;
var router = express.Router();
router.get('/', function(req, res) {
var test;
function SomeFunction(){
....some function that calculates a value
res.json({ message: 'Your value is' + test });
}
});
app.use('/api', router);
app.listen(port);
I want to perform some function to calculate a value before returning it. As is stands the server will respond immediately. I am sure this is very basic but i looked everywhere and cant find an answer about how to wait for my express server to calculate the value before issuing a response.

You are not calling your function SomeFunction anywhere. If you call it, express will wait. Just write after the function definition: SomeFunction();.

var express = require('express');
var app = express();
var bodyParser = require('body-parser');
app.use(bodyParser.urlencoded({ extended: true }));
app.use(bodyParser.json());
var port = process.env.PORT || 8080;
var router = express.Router();
router.get('/', function(req, res) {
var test;
function SomeFunction(res){
....some function that calculates a value
res.json({ message: 'Your value is' + test });
}
//call it with res parameter
someFunction(res);
});
app.use('/api', router);
app.listen(port);

Related

Both POST/GET requests yield a 404 error in Postman. Is my Express routing to blame?

I am intending to set up a Node.js server with MongoDB to handle HTTP CRUD requests. Upon setting up my endpoint I was initially able to receive POST/GET requests, however the handling of the document objects became the issue. Upon trying to fix this issue I am now unable to POST/GET at all? Is this simply a syntax issue or is my code doomed?
const MongoClient = require('mongodb').MongoClient;
var QRCode = require('qrcode');
var canvasu = require('canvas');
var express = require('express');
var mongoose = require('mongoose')
var app = express();
var port = process.env.PORT || 3000;
var bodyParser = require('body-parser');
app.use(bodyParser.urlencoded({ extended: false }));
app.use(bodyParser.json());
var db;
var collection
var Patient = require('./ShiftAssist/models/patientModel');
var router = express.Router();
''
CODE FOR CONNECTION
''
router.get('/patients/:Pnum', function(req,res,next){
Patient.findOne({Pnum:req.params.Pnum},function(err,patient){
if (err) return next(err);
res.json(patient);
})
});
app.use('/', router);
app.listen(3000, function () {
console.log('Example app listening on port ' + port + '!');
});
Expected: GET request to http://127.0.0.1:3000/patients/XXXXXX with a document identifier, returns entire document
Actual: Timeout Error
try to change you route by /patients/:Pnum
and your request should be http://127.0.0.1:3000/patients/XXXXXX
source: https://expressjs.com/en/guide/routing.html
EDIT: Code i used so far
var express = require('express');
var app = express();
var router = express.Router();
router.get('/patients/:Pnum', function (req, res, next) {
setTimeout(() => res.json({ ok: req.params.Pnum }), 1000)
});
app.use('/', router);
app.listen(3000);

NodeJs route not working

I am new to NodeJs. I am getting error with below code.
var express = require('express'),
app = express(),
bodyParser = require('body-parser'),
port = process.env.PORT || 9090,
mongoose = require('mongoose'),
Cheque = require('./models/cheque'),
router = express.Router();
app.use(bodyParser.urlencoded({ extended: true }));
app.use(bodyParser.json());
mongoose.connect('http://localhost:27017/utils/chequeman');
router.route('/cheques').post(function (req, res) {
console.log('u r in cheques.');
var cheque = new Cheque();
cheque.chequeReceiptDate = req.body.chequeReceiptDate;
cheque.save(function (err) {
if (err)
res.send(err)
res.json({ message: 'Cheque details added' });
});
});
app.use('/api', router);
app.listen(port);
console.log('Magin happens at' + port);
When I am trying POST request in postman I am getting response as "Cannot POST /api/cheques"
Please help.
Try to declare the variables that you are using.
let express = require('express');
let app = express();
let bodyParser = require('body-parser');
let port = process.env.PORT || 9090;
let mongoose = require('mongoose');
let Cheque = require('./models/cheque');
let router = express.Router();
Take your API static
app.use('/CHEQUEDIRECTORY', express.static(__dirname + '/CHEQUEDIRECTORY'))
Don't forget to export modules on you API.
Have you installed the packages correctly?

Cannot get Express to find routes

I am working on making adjustments to teammates code and I haven't been able to understand how they have done their routing. I am attempting to have Express run a middleware script when an end-user goes to a new session of the web application.
I don't know what to test next to figure out how they have done their routing.
Main.js
// Dependencies
var http = require('http');
var express = require('express');
var path = require('path');
var logger = require('morgan');
var cookieParser = require('cookie-parser');
var bodyParser = require('body-parser');
var busboy = require('connect-busboy');
var cors = require('cors');
var mongoose = require('mongoose');
// Configuration
var config = require('./config');
var twilio = require('twilio');
// Database
mongoose.connect(config.database);
var db = mongoose.connection;
db.on('error', console.error.bind(console, 'connection error:'));
db.once('open', function(){
console.log('Connected to database');
});
var app = express();
app.set('port', process.env.PORT || 3000);
// Setup middleware
app.use(logger('dev'));
app.use(bodyParser.json());
app.use(bodyParser.urlencoded({ extended: true }));
app.use(cookieParser(config.sessionSecret));
app.use(express.static(path.join(__dirname, 'dist')));
app.use(busboy());
app.use(cors({
origin: true,
credentials: true
}));
app.all('/*',function(req,res){
twilio.notifyOnSession();
console.log('Message Sent');
})
var server = http.createServer(app);
var port = app.get('port');
server.listen(port);
console.log('Listening on port ' + port);
// Load server router
require('./router')(app);
/router/index.js
var path = require('path');
module.exports = function(app){
console.log('Initializing server routing');
require('./auth')(app);
require('./api')(app);
// Determine if incoming request is a static asset
var isStaticReq = function(req){
return ['/auth', '/api', '/js', '/css'].some(function(whitelist){
return req.url.substr(0, whitelist.length) === whitelist;
});
};
// Single page app routing
app.use(function(req, res, next){
if (isStaticReq(req)){
return next();
}
res.sendFile(path.join(__dirname, '../dist/index.html'));
});
};
Your app.all('/*' is swallowing all requests before they can hit your router.
Don't do that.
I was able to resolve the issue by creating a new route with twilio.js and having the router look for the url twilio/new. Thanks all for the help.

Node express cannot get static file

This is the picture of my server
https://drive.google.com/file/d/1GA57RyYsc5ik1pSlLhAGtgGjbp_vLFoH/view?usp=sharing
When I go to http://localhost:3000/
I get the error message: Cannot Get/
myserver.js
// TODO: mount the tigers route with a a new router just for tigers
// exactly like lions below
var express = require('express');
var bodyParser = require('body-parser');
var app = express();
var _ = require('lodash');
var morgan = require('morgan');
var lionRouter = require('./lions');
var tigerRouter = require('./tigers');
app.use(morgan('dev'))
app.use(express.static('client'));
app.use(bodyParser.urlencoded({extended: true}));
app.use(bodyParser.json());
// this is called mounting. when ever a req comes in for
// '/lion' we want to use this router
app.use('/lions', lionRouter);
app.use(function(err, req, res, next) {
if (err) {
res.status(500).send(error);
}
});
app.listen(3000);
console.log('on port 3000');
Whenever you are trying to visit any url on the browser , then browser makes a GET request to that url, in your case you are not sending any response on the url: "http://localhost:3000/. You can try something like this.
app.route('/*')
.get(function(req, res) {
res.sendFile(path.resolve("./client") + '/index.html'));
});
Check the naming you used, it shows myserver.js instead of server.js as in the picture you uploaded.
Check your routing on line 10 of you code
var lionRouter = require('./lions');
var tigerRouter = require('./tigers');
. try this edited codes
server.js
// TODO: mount the tigers route with a a new router just for tigers
// exactly like lions below
var express = require('express');
var bodyParser = require('body-parser');
var app = express();
var _ = require('lodash');
var morgan = require('morgan');
var lionRouter = require('./server/lions');
var tigerRouter = require('./server/tigers');
app.use(morgan('dev'))
app.use(express.static('client'));
app.use(bodyParser.urlencoded({extended: true}));
app.use(bodyParser.json());
// this is called mounting. when ever a req comes in for
// '/lion' we want to use this router
app.use('/lions', lionRouter);
app.use(function(err, req, res, next) {
if (err) {
res.status(500).send(error);
}
});
app.listen(3000);
console.log('on port 3000');
Express static directory is given client but it is present on parent directory.
So i have resolve this issue with path module and now this will work for you.
// TODO: mount the tigers route with a a new router just for tigers
// exactly like lions below
var express = require('express');
var bodyParser = require('body-parser');
var app = express();
var _ = require('lodash');
var morgan = require('morgan');
var path = require('path')
var lionRouter = require('./lions');
var tigerRouter = require('./tigers');
app.use(morgan('dev'))
app.use(express.static(path.join(__dirname, '../client')));
app.use(bodyParser.urlencoded({extended: true}));
app.use(bodyParser.json());
// this is called mounting. when ever a req comes in for
// '/lion' we want to use this router
app.use('/lions', lionRouter);
app.use(function(err, req, res, next) {
if (err) {
res.status(500).send(error);
}
});
app.listen(3000);
console.log('on port 3000');
Your code works fine after commenting the following three lines of your code:
var lionRouter = require('./lions');
var tigerRouter = require('./tigers');
app.use('/lions', lionRouter);
Check if any error is present in LionsJS.

Error in implementing router

Here is my code.
server.js
var express = require('express'),
bodyParser = require('body-parser'),
log = require('./libs/log')(module),
api = require('./libs/api.js'),
app = express();
// settings
app.set('port', 5000);
// to process post requests
app.use(bodyParser.urlencoded({
extended: true
}));
app.use(bodyParser.json());
// routes
rawQuestionRouter = require('./routes/rawQuestionRoutes.js');
app.use('/rawQuestions', rawQuestionRouter);
and routes/rawQuestionRoute.js:
var express = require('express');
var routes = function() {
var rawQuestionRouter = express.Router();
rawQuestionRouter.route('/test')
.post(function(request, response) {
log.debug(request.body);
response.send('raw question saved');
});
return rawQuestionRouter;
}
module.exports = routes;
Update:
When I make a POST request on '/rawQuestions/test' the server don't respond. Why?
You're exporting the routes function, which is not a router (it returns one, but that's not the same).
There are several solutions:
// server.js
app.use('/rawQuestions', rawQuestionRouter());
Or:
// routes/rawQuestionRoute.js
module.exports = routes();
Or just remove the entire routes function altogether and export the router instance directly.

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