So I am fairly new to the backend. Anyway, I want to create an API that I can use in the front-end, the error I am facing when I try to send a request to the localhost:5000/elements Postman is giving me Error: connect ECONNREFUSED 127.0.0.1:5000 if someone could help me it would be awesome. Thanks
var fs=require('fs');
var data=fs.readFileSync('books.json');
var elements=JSON.parse(data);
const express = require("express");
const app = express();
const cors=require('cors');
const Port = 5000
app.listen(process.env.Port, () => console.log("Server Start at " + Port));
app.use(express.static('public'));
app.use(cors());
app.get('/elements',alldata);
function alldata(request,response)
{
response.send(elements);
}
app.get('/elements/:element/',searchElement);
function searchElement(request,response)
{
var word=request.params.element;
word=word.charAt(0).toUpperCase()+word.slice(1).toLowerCase();
console.log(word);
console.log(elements[word]);
if(elements[word])
{
var reply=elements[word];
}
else
{
var reply={
status:"Not Found"
}
}
console.log(reply.boil);
response.send(reply);
}
This problem usually happens if you forget to run npm start.
Either way, I recommend moving the app.listen to the bottom of the code. It helps with readability, and it will mount all of code before running the Express server.
Your process.env.Port is also undefined. Change it to const port = process.env.Port || 5000 so you can get a fallback value. Change it also in the app.listen.
Then, define allData and searchElement so they are located before the app.get('/elements'). Finally, after you have done all of this, make sure that the request type in Postman is GET.
process.env.Port is unrelated to Port.
It's
app.listen(Port, () => console.log("Server Start at " + Port));
Related
Having a problem where the following code returns Cannot read property 'swaggerUi' of undefined each time I run node app.js. The code below is the entirety of app.js.
I have tried a bunch of different npm installs, computer restarts, and all of that. Nothing seems to change it.
var SwaggerExpress = require('swagger-express-mw');
var app = require('express')();
module.exports = app; // for testing
var config = {
appRoot: __dirname // required config
};
SwaggerExpress.create(config, function(err, swaggerExpress) {
if (err) { throw err; }
// install middleware
swaggerExpress.register(app);
var port = process.env.PORT || 10010;
app.use(swaggerExpress.runner.swaggerTools.swaggerUi());
app.listen(port, function() {
console.log('Server running at http://127.0.0.1:' + port + '/');
});
if (swaggerExpress.runner.swagger.paths['/hiMom']) {
console.log('try this:\http://127.0.0.1:' + port + '/docs');
}
});
Here is a github sample link that might be be helpful
sample-swagger-for-nodejs.
SOLVED: I'm not sure what the problem was, but getting a fresh clone of the GitHub repo solved the problem.
I have the following example using Node.js for the server that sends data via Socket.io to a Javascript file. All works well locally, but when I uploaded to Heroku, it does not. I have tried a lot of tips I found online, but I am always stuck and can't get it through. At the moment, I don't get errors, but I also can't see the values coming through.
Here is the code I use at the moment:
var express = require('express');
var socket = require('socket.io');
//store the express functions to var app
var app = express();
//Create a server on localhost:3000
var server = app.listen(process.env.PORT || 3000);
//var server = app.listen((process.env.PORT || 3000, function(){
//console.log("Express server listening on port %d in %s mode", this.address().port, app.settings.env);
//});
//host content as static on public
app.use(express.static('public'));
console.log("Node is running on port 3000...");
//assign the server to the socket
var io = socket(server);
//dealing with server events / connection
io.sockets.on('connection', newConnection); //callback
//function that serves the new connection
function newConnection(socket){
console.log('New connection: ' + socket.id);
socket.on('incomingDataToServer', emitFunction);
function emitFunction(data){
//setInterval(() => socket.broadcast.emit('ServerToClient', new Date().toTimeString()), 1000);
let randNum;
setInterval(function(){
//get a random value, and assign it a new variable
randNum = getRandomInt(0, 100);
}, 1000);
socket.broadcast.emit('ServerToClient', randNum);
//following line refers to sending data to all
//io.sockets.emit('mouse', data);
console.log(randNum);
}
}
And the Javascript here:
let socket;
socket = io();
socket.on('ServerToClient', socketEvents);
function socketEvents(data){
incomingData = data;
console.log(data);
}
Any help is appreciated.
Thanks
Write app.use before the app listen
and modify app.listen as below and check heroku logs for console message.
app.use(express.static('public'));
var server = app.listen(port, function() {
console.log('Server running on ' + port + '.');
});
if It still not work let me know.
I have this node.js server. The problem is sometimes I notice that it gets stuck. That is the client can make requests, but the server doesn't respond, rather it doesn't end the response, it just gets stuck in the server side. If I look in client side dev tools on the http request, it has a gray circle icon meaning waiting for server response. Even if I wait 10 minutes, nothing happens.
The server side also writes things to console on the requests, which doesn't happen when it gets stuck.
On the node.js console, if I then press ctrl+c when it got stuck, I then suddenly see all the console.log messages just appear on the console, and at the same time, the dev tools, recieves all the responses from the server side, i.e. the gray circle changes to green.
Does anyone know what this problem is?
Thanks
var express = require('express');
var https = require("https");
var fse = require("fs-extra");
var bodyParser = require('body-parser');
// INFO
var root = __dirname + '/public';
setUpServer();
// SET UP SERVER
function setUpServer() {
var app = express();
app.use(express.static(root));
app.use(bodyParser.urlencoded({ extended: false }))
app.get('/', function (req, res) {
var dest = 'index.html';
res.sendFile(dest, { root: root + "/pong" });
});
app.post('/get_brain', function (req, res) {
res.end("1");
console.log('Sent master brain to a client!');
});
app.post('/train_and_get_brain', function (req, res) {
res.end("1");
console.log('Sent master brain to a client!');
});
var privateKey = fse.readFileSync('sslcert/key.pem', 'utf8');
var certificate = fse.readFileSync('sslcert/cert.pem', 'utf8');
var credentials = {key: privateKey, cert: certificate};
var httpsServer = https.createServer(credentials, app);
httpsServer.listen(process.env.PORT || 3000, function () {
var host = httpsServer.address().address;
var port = httpsServer.address().port;
console.log('AI started at https://%s:%s', host, port);
});
}
I am currently using crypto.js module to hash things. It was working for a while then I started getting this error:
Here is the foundation of my server:
process.stdout.write('\033c'); // Clear the console on startup
var
express = require("express"),
app = express(),
http = require("http").Server(app),
io = require("socket.io")(http),
path = require("path"),
colorworks = require("colorworks").create(),
fs = require("fs"),
crypto = require("crypto");
function md5(msg){
return crypto.createHash("md5").update(msg).digest("base64");
}
function sha256(msg) {
return crypto.createHash("sha256").update(msg).digest("base64");
}
http.listen(443, function(){
// Create the http server so it can be accessed via 127.0.0.1:443 in a web browser.
console.log("NJ project webserver is running on port 443.");
// Notify the console that the server is up and running
});
app.use(express.static(__dirname + "/public"));
app.get("/", function(request, response){
response.sendFile(__dirname + "/public/index.html");
});
I am aware that these functions are creating the problem:
function md5(msg){
return crypto.createHash("md5").update(msg).digest("base64");
}
function sha256(msg) {
return crypto.createHash("sha256").update(msg).digest("base64");
}
The problem being, if these functions don't work (which they don't anymore), roughly 200 lines of code will go to waste.
This error is triggered by attempting to hash a variable that does not exist:
function md5(msg){
return crypto.createHash("md5").update(msg).digest("base64");
}
function sha256(msg) {
return crypto.createHash("sha256").update(msg).digest("base64");
}
md5(non_existent); // This variable does not exist.
What kind of data are you trying to hash ? Where does it come from ?
I would check the value of msg first then I would try :
crypto.createHash('md5').update(msg.toString()).digest('hex');
You could also use these packages instead:
https://www.npmjs.com/package/md5
https://www.npmjs.com/package/js-sha256
I am reading Professional Node.js and i'm trying to understand connect HTTP middleware framework. I created a simple middleware that returns a function that replies with a custom test string:
function replyText(text) {
return function(req, res) {
res.end(text);
};
}
module.exports = replyText;
But when i try to use this middleware in a connect server. Node gives me an error:
/Users/socomo22/work/hello_world_app_v2.js:8
var app = connect.createServer(replyText('Hello World!'));
^
TypeError: undefined is not a function
But when i simply use:
var app = connect();
app.listen(8080)
It runs without giving any error. I don't understand whether i'm doing any syntatical mistake. How would i use this simple middleware? This is my connect server file:
var connect = require('connect');
// middlewares
var replyText = require('./reply_text');
var app = connect();
var app = connect.createServer(replyText('Hello World!'));
app.listen(8080, function() {
console.log('listening on 8080 port')
});
As pointed by documentation use use API to mount a middleware and a http module to create an instance of server although you can create an instance just with connect as pointed here.
As pointed by #FranciscoPresencia adding .js extension while you require a your local module is optional.
var replyText = require('./reply_text.js');
So your code should look like this and i tested it. Working as intended
var connect = require('connect')
var http = require('http')
var app = connect();
// middlewares
var replyText = require('./reply_text.js');
app.use(replyText('Hello World!'));
http.createServer(app).listen(8080, function() {
console.log('listening on 8080 port')
});
Note: Try to avoid ports like 8080, 80 etc as its a reserved ports that might be used by other apps. This sometimes may cause node to fail.
Adding the output screenshot for your reference
Here You can start server in this way...
var connect = require('connect');
var http = require('http');
var app = connect();
var replyIN = require('./connetFile.js')
app.use(replyIN('Hello there m back again'));
http.createServer(app).listen(8888,function(){console.log('Server has started');});
And this is your connectFile.js
function replyIN(text){
return function (req, res) {
res.end(text);
};
};
module.exports = replyIN;