js and am trying to create a web server and server side code for my web application.
I understand express is used to get access to all static files.
I am trying to start a simple server using express as follows:
var express = require("express");
var url = require("url");
var http = require("http");
var port = 3000;
var app = express();
app.use(express.static(__dirname + "/Client"));
http.createServer(app).listen(port, function(req,res){
console.log("Server running at: " + "http://" + port);
res.writeHead(200,{
"Content-Type":"text/plain"
});
});
I cant seem to do anything with my res variable in my callback, which I am trying to use as a response object. Allowing me to do things like:
res.end(¨hello world¨);
Is this callback even allowed, or how can I start sending responses etc. I am on virtual box (linux) machine, and using res always gives error (undefined methods etc.). Thanks in advance,
http.createServer(app).listen(port, [hostname], [backlog], [callback])
There are no parameters given to the callback function. This is why req and res are undefined.
So you may change your code to:
app.listen(port, function(){
console.log("Server running at: " + "http://localhost:" + port);
});
app.get('/', function(req,res) {
res.status(200).send('Hello World!')
})
So take a look at the documentation of app.listen() and app.get()
Related
I am using post method in nodejs
Well it is working fine when I run it using postman
but when I run it in my browsers it shows error
Cannot GET /listUsers
and
listUsers:1 GET http://localhost:8081/listUsers 404 (Not Found)
this
here is my node js code
var express = require('express');
var bodyParser = require('body-parser');
var app = express();
app.use(bodyParser.json());
app.use(bodyParser.urlencoded({extended:false}));
app.post('/listUsers', function (req, res) {
var f = parseInt(req.body.f);
console.log("hello" + f);
var l = parseInt(req.body.l);
var sum = Number(f + l);
res.send('The sum is: ' + Number(sum));
})
var server = app.listen(8081, function () {
var host = server.address().address
var port = server.address().port
console.log("Example app listening at http://%s:%s", host, port)
})
here is my jquery code from where I am sending data
usid();
function usid(med){
var f = "my new name";
$.ajax({
crossDomain: true,
url:"http://localhost:8081/listUsers",
method:"POST",
data:{med,f:f},
success:function(data,status){
console.log("send");
}
})
}
can I get where I am doing mistake?
You are not submitting any form/storing any resource. What you are trying should ideally be done with GET.
Reasons it is not working with browser:
Visiting a page by changing url is a GET method. You do not have a GET method defined in your app for this route. Only one POST method.
What you can do:
Change POST to GET both in server and your AJAX. Change both methods accordingly. You will then have to pass query params(google something and everything after the question mark is how query Params work).
Gone through code as below couldnt understand the working of code 1...what is the difference between the two codes below
**
What is the point of using http and express togather in code 1?
Code1
var app = require('express')();
var http = require('http').Server(app);
app.get('/', function(req, res)
{
res.sendFile(__dirname+'/index.html');
});
http.listen(3000, function()
{
console.log('listening on *:3000');
});
The same thing can be done as
Code2
var express=require('express');
var app=express();
var socket=require('socket.io');
app.get('/',function(req,res){
res.sendFile(__dirname+'/index.html');
}).listen(8080);
console.log("Listening to port 8080");
You're asking about the difference of expressjs own server and http server. They are different in many ways.
Solved here
The app object conventionally denotes the Express application which is created by top level express() function exported by the Express module.
http.listen(): Starts the HTTP server listening for connection
In the second case it works app.listen() which binds and listens for connection on the specified port and it identical to http.listen()
I've got an AWS EC2 MEAN instance up and running (partially). The app is a RESTful JSON service and as far as I can tell is up and running as expected:
var app = require('./app');
var port = process.env.PORT || 3000;
var server = app.listen(port, function() {
console.log('Express server listening on port ' + port);
});
console output:
node server.js
Express server listening on port 3000
Db.prototype.authenticate method will no longer be available in the
next major release 3.x as MongoDB 3.6 will only allow auth against
users in the admin db and will no longer allow multiple credentials on
a socket. Please authenticate using MongoClient.connect with auth
credentials.
I've also added the Inbound Security Group for port 3000
testing the API out in the browser is where I run into problems... If I attempt to GET a list of objects using http://ec2-XX-XX-XX-XX.com:3000/belts the call eventually times out. However when I try a GET for a single object using http://ec2-XX-XX-XX-XX.com:3000/belts/some_id_here I get a valid 200 response with the expected object.
Of course everything works as expected locally. What am I missing?
Thanks in advance
//edit with requested code formatted :)
//app.js
var express = require('express');
var app = express();
var BeltController = require('./controller/BeltController');
app.use('/belts', BeltController);
//Belt Controller
router.get('/', function (req, res) {
Belt.find({}, function (err, belts) {
if (err) {
return res.status(500).send("There was a problem finding the Belt. " + err);
}
res.status(200).send(belts);
});
});
I want to create a simple Node.js server to do the following :
With my application I just do the command http.get(Node.Js_Server_address/json) to get the json file data stored on my server.
Could please help me with a tutorial? Any help would be appreciated!
This is very simple example of node.js server:
var app = require('./app');
var http = require('http');
var server = http.createServer(app);
server.listen(8080, function() {
console.log("listening to: http://127.0.0.1:8080");
});
// routing
app.get('/', function (req, res) {
res.sendfile(__dirname + '/index.html');
});
there is a nice tutorial here and here ...
you can use npm to install node.js and all the packages that you need for it.
hope it helps.
There are lots of examples on this topic, i think you should make some googling before next time.
You can create a REST server via express module of nodeJs. In your server folder use npm install express to download express module. You can get more information about express from here. After that create a server.js file in your server folder.In server.js
var express = require('express');
var app = express();
var PORT = 8080;
/* req stands for request, res stands for response */
app.get('/json',function(req,res){
res.json(yourData);
})
app.listen(PORT,function(){
console.log('Express is listening port:' + PORT + '!');
})
So this should do the work. Let me know if this helps you.
I'm making a web-app that makes use of nodejs, mongodb, socket.io, express and mongoose.
I can start my server and correctly get the wanted html file in my browser when browsing to my localhost.
The problem I have is getting my socket.io to work.
On my server side everything works fine : I get " info - socket.io started " in my terminal.
But when surfing to my browser I get this in my browser console
Failed to load resource: the server responded with a status of 404 (Not Found)
Uncaught ReferenceError: io is not defined
This is how i connect to socket.io.js
<script src="/socket.io/socket.io.js"></script>
and my map structure looks like this:
map
-app.js
-public
--index.html
-node_modules
--socket.io
--mongodb
--express
--jade
--mongoose
Does anyone knows what the mistake is I've made?
(it's actually the same problem as here: Node.js socket.io.js not found or io not defined )
Thanks in advance!
EDIT:
My code on the server side is this:
var app= require('express').createServer();
var io = require('socket.io').listen(app);
var mongoose = require('mongoose');
var db = mongoose.connect('mongodb://localhost/db');
app.listen(3030);
console.log("server started");
app.get('/',function(req,res){
res.sendfile(__dirname + '/public/index.html');
});
io.sockets.on('connection',function(socket){
console.log("connection made");
});
The first log, gets logged in the terminal ("server started"), but the second one ("connection made") doesn't get logged. So the connection isn't made.
I thought that was because of the wrong "set up" in my client side.
Check out the express migration guide 2->3
https://github.com/visionmedia/express/wiki/Migrating-from-2.x-to-3.x
Something like this should work
var express = require('express');
var app = express();
var http = require('http');
var server = http.createServer(app);
var io = require('socket.io').listen(server);
var mongoose = require('mongoose');
var db = mongoose.connect('mongodb://localhost/db');
server.listen(3030);
console.log("server started");
app.get('/',function(req,res){
res.sendfile(__dirname + '/public/index.html');
});
io.sockets.on('connection',function(socket){
console.log("connection made");
});
var app = express();
app.set('port', process.env.PORT || 3000);
...
var server = http.createServer(app).listen(app.get('port'), function(){
console.log("Express server listening on port " + app.get('port'));
});
var io = socket.listen(server);
io.sockets.on('connection', function () {
console.log('hello world im a hot socket');
});