I'm trying to build a Twitter streaming web application using node.js socket.io and twit.
var express = require('express')
, app = express()
, http = require('http')
, server = http.createServer(app)
,Twit = require('twit')
, io = require('socket.io').listen(server);
server.listen(8080);
// routing
app.get('/', function (req, res) {
res.sendfile(__dirname + '/index.html');
});
var watchList = ['love', 'hate'];
io.sockets.on('connection', function (socket) {
console.log('Connected');
var T = new Twit({
consumer_key: ''
, consumer_secret: ''
, access_token: ''
, access_token_secret: ''
})
T.stream('statuses/filter', { track: watchList },function (stream) {
stream.on('tweet', function (tweet) {
io.sockets.emit('stream',tweet.text);
console.log(tweet.text);
});
});
});
Here's my client side
<script src="/socket.io/socket.io.js"></script>
<script src="https://ajax.googleapis.com/ajax/libs/jquery/1.7.2/jquery.js"></script>
<script>
$(function(){
var socket = io.connect('http://localhost:8080');
socket.on('tweet', function(tweet) {
$(
'<div class="tweet">' + tweet.text + '</div>');
});
});
</script>
</div>
When I run node app.js and try to connect to localhost:8080 I just get a blank page, even if everything ( soket.io, jquery, ... ) seems to have loaded correctly.
Here's a sample of the server output :
info - socket.io started
debug - served static content /socket.io.js
debug - client authorized
info - handshake authorized pwH0dbx4WvBhzSQXihpu
debug - setting request GET /socket.io/1/websocket/pwH0dbx4WvBhzSQXihpu
debug - set heartbeat interval for client pwH0dbx4WvBhzSQXihpu
debug - client authorized for
debug - websocket writing 1::
debug - websocket writing 5:::{"name":"stream","args":["RT #mintycreative: Great to chat today RT #SharonHolistic: Treatments available tomorrow http://t.co/5Poq3KU08u Book yours now #WestMidsHou…"]}
debug - websocket writing 5:::{"name":"stream","args":["RT #laurenpeikoff: #BREAKING #ScottsdalePD confirms - police are investigating Michael Beasley for alleged sexual assault. #12News #azcentr…"]}
Hope you can help me to correct my mistakes.
Problem solved
Here's the code without any mistakes : (server side)
var express = require('express')
, app = express()
, http = require('http')
, server = http.createServer(app)
,Twit = require('twit')
, io = require('socket.io').listen(server);
server.listen(8080);
// routing
app.get('/', function (req, res) {
res.sendfile(__dirname + '/index.html');
});
var watchList = ['love', 'hate'];
var T = new Twit({
consumer_key: ''
, consumer_secret: ''
, access_token: ''
, access_token_secret: ''
})
io.sockets.on('connection', function (socket) {
console.log('Connected');
var stream = T.stream('statuses/filter', { track: watchList })
stream.on('tweet', function (tweet) {
io.sockets.emit('stream',tweet.text);
});
});
});
(client-side)
<script src="/socket.io/socket.io.js"></script>
<script src="https://ajax.googleapis.com/ajax/libs/jquery/1.7.2/jquery.js"></script>
<script>
var socket = io.connect('http://localhost:8080');
socket.on('stream', function(tweet){
$('#tweetd').append(tweet+'<br>');
});
</script>
<div id="tweetd"></div>
</div>
The first issue is that you are constructing a new twitter listener each time a socket connection is opened. You should move that outside of the connection event. This is likely not ideal. I'm not sure how the twitter module is handling that internally but it likely actually is creating a new connection to their API each time a websocket connects.
On the client side you jQuery could bit a bit different. If you just wanted to add a tweet to the page each time a tweet occurs, append a new tweet to the body element with $('body').append()
See this gist for reference.
Related
Just starting to learn express. Would wish to forward a json file to another location for processing/ingestion that i recieved from a request from webhook using POST url endpoint.
I am planning to pass this json file to a cpp program
I have the following code
var request = require('request'),,
express = require('express'),
path = require('path');
http = require('http');
const port = 5000;
var app = express();
// for json parser
app.use(express.json());
app.post('/gethub', function(req, res) {
console.log("Got response: " + res.statusCode);
console.log("Got header: " + res.getHeaderNames());
console.log("Got status Message: " + res.statusMessage );
var data = req.body;
var name = data.pusher.name;
var node_id = data.sender.node_id;
res.status(200).send(res.json( { name : name,
Nodeid : node_id });
});
var server = app.listen(app.get('port'), function() {
var host = server.address().address
var portid = server.address().port
console.log('App listening at http://%s:%s', host, portid)
console.log("App listening on port " + app.get('port'));
});
THanks for your help
Think of Express as a framework that behaves as a web server. What you really are doing is writing an API listening in the port 5000 in your case. The function seems ok so it will be accesible while making a HTTP request using the POST method.
Express docs about routing
I'm trying to use a restful service to access data that is posted to a MongoDB cluster. My problem is that I can't even connect to the service, the get request doesn't seem to be working. Console.log("test")is not reached and I'm met with a blank console, so I don't think the readystate is changing.
I've done a ton of troubleshooting and found that the link works on its own (https://RESTfulServiceExample.[REPL.IT USERNAME].repl.co/items) and displays the data when pasted into the search bar. I've also tried changing browsers and even compared to my friend's code which works and STILL I can't even seem to connect.
I'm sure it's just some dumb little mistake but I'm completely at a loss here so any help is MUCH appreciated!
File with get request. I edited out the username. 'item' is the name of the MongoDB cluster.
<html>
<head>
<script type="text/javascript">
var xhttp = new XMLHttpRequest();
xhttp.onreadystatechange = function() {
if (xhttp.readyState == 4 && this.status == 200) {
console.log("test"); //NOT REACHED
var responseObj = JSON.parse
(xhttp.responseText);
};
}
//PROBLEM HERE
xhttp.open("GET", "https://RESTfulServiceExample.[REPL.IT USERNAME].repl.co/items", true);
xhttp.send();
</script>
<script type="text/javascript" src="https://canvasjs.com/assets/script/canvasjs.min.js">
</script></head>
<body>
<div id="chartContainer" style="height: 300px; width: 100%;">
</div>
</body>
</html>
RESTful Service:
Index.js: (edited out username and password of mongodb.
var express = require('express'); // control-shift-S to bring up shell in repl.it and npm
install express / other packages
var app = express();
var port = 5000; // the port is automatically routed by the repl.it domain
mongoose = require('mongoose');
Item = require('./model/model.js');
bodyParser = require('body-parser');
mongoose.Promise = global.Promise; // for asynchronous callbacks
mongoose.connect('mongodb+srv://[USERNAME]:[PASSWORD]#cluster0.thmkp.mongodb.net/Pokemon?
retryWrites=true&w=majority');
app.use(bodyParser.urlencoded({ extended: true }));
app.use(bodyParser.json());
var routes = require('./routes/routes'); //importing route
routes(app); //register the route
app.listen(port);
Routes.js
'use strict';
module.exports = function(app) {
var itemList = require('../controllers/controller');
app.route('/items')
.get(itemList.list_items)
.post(itemList.create_item);
app.route('/items/:id')
.get(itemList.get_item)
.put(itemList.update_item)
.delete(itemList.delete_item);
};
Try to change
if (this.readyState == 4 && this.status == 200) {
// your code block
}
I am new with node.js and socket.io i was able to start a local server via node.js and get the numbers of client connected on port 3000 using console.log now my next step is displaying it on my HTML, i was reading about how to include socket.io.js on HTML and tried the on('connect') method but its returning a undefined error , Any advice would be great thanks in advance!
My server.js
var express = require('express');
var app = express();
var server = require('http').createServer(app);
var io = require('socket.io').listen(server);
users = [];
connections = [];
server.listen(process.env.PORT || 3000);
console.log('listening to port 3000, server is running..');
app.get('/', function (req,res){
res.sendFile(__dirname + '/index.html');
});
io.sockets.on('connection',function(socket){
connections.push(socket);
console.log('Connected: %s sockets connected', connections.length);
//Disconnect
socket.on('disconnect', function(data){
users.splice(users.indexOf(socket.username), 1);
updateUsernames();
connections.splice(connections.indexOf(socket), 1);
console.log('Disconnected: %s sockets connected', connections.length);
});
});
On my index.html
//This is located on my html head tag
<script src="http://localhost/socket.io/socket.io.js"></script>
<div class="col-lg-12">
<h1 id="users"></h1>
</div>
<script>
var socket = io.connect('http://localhost:3000');
socket.on('connect',function(){
$('#users').html = socket.users.length;
));
</script>
I manage to display the numbers of connected users on client side by emitting a event than client will receive and display it.
revised my server.js
io.sockets.on('connection',function(socket){
connections.push(socket);
console.log('Connected: %s sockets connected', connections.length);
//added this below
io.sockets.emit ('totalUsers', {count: connections.length});
//Disconnect
socket.on('disconnect', function(data){
users.splice(users.indexOf(socket.username), 1);
updateUsernames();
connections.splice(connections.indexOf(socket), 1);
console.log('Disconnected: %s sockets connected', connections.length);
//added this below
io.sockets.emit ('totalUsers', {count: connections.length});
});
Then on my index.html
socket.on('totalUsers', function(data){
console.log(data.count);
$users.html('Total connected users: '+data.count);
});
You must include or link your socket.io.js before the io.connect() on your html. like this
<script type="text/javascript" src="assets/nodejs/node_modules/socket.io-client/dist/socket.io.js"></script>
you can use this cdn
https://cdnjs.cloudflare.com/ajax/libs/socket.io/2.0.3/socket.io.js
but it is better to use your socket.io.json your local folder it is in the node_modules/socket.io-client/dist/socket.io.js if you are using latest version of node.
Hope it will help.
I want to visualize the real time sensor data(Streaming data).For that i used, node.js, html and mysql. Mysql used to store real time sensor data, index.html implements google chart that doPoll app.js file, app.js file provides connection to mysql. I am able to visualize the data from the same system but when i entered url(Public IP) Chrome display "Failed to loadre source : net : : ERR_CONNECTION_REFUSED" and firefox display "Cross-Origin Request Blocked: The Same Origin Policy disallows reading the remote resource at http://localhost:8686/temperatureData. (Reason: CORS request failed)." I have forwarded port 8686 from Router.But i am able to view data in json format using both browser from remote system.Code for app.js is as below:
/**
*
*/
var http = require('http');
var fs = require('fs');
var port = 8686;
var i=0;
var j=0;
function randomInt(low, high) {
return Math.floor(Math.random() * (high - low) + low);
}
// 404 response
function send404Response(response){
response.writeHead(404,{"Content-Type": "text/plain" });
response.write("Error 404: Page not found");
response.end();
}
// handle the user request..
http.createServer(function(req, res) {
console.log('New incoming client request for ' + req.url);
res.writeHeader(200, {
'Content-Type' : 'application/json'
});
switch (req.url) {
case '/temperatureData':
var mysql=require('mysql');
var connection=mysql.createConnection({
host:'localhost',
user:'root',
password:'root',
database:'feedback',
port:3306
});
var query=connection.query(
// make sure with table name
'SELECT * FROM DEMO2',function(err,result,fields){
if(err) throw err;
//res.write('{"value" :' + result[i].tempvalue + ',"value1":' + result[i].value + '}');
// make sure with tabel fieldname (ex-tempvalue) ok
// side by side open mysql
res.write('{"value" :' + result[i].tempvalue + '}');
//res.write('{"value1":' + result[i].value + '}');
console.log('Temperature:', result[i].tempvalue );
i++;
res.end();
connection.end();
});
break;
case '/temperature':
res.writeHead(200, 'text/html');
var fileStream = fs.createReadStream('index.html');
fileStream.pipe(res);
break;
default:
send404Response(res);
}
}).listen(port);
console.log('Server listening on http://localhost:' + port);
Code for Index.html file shown below:
<html>
<head>
<script src="https://ajax.googleapis.com/ajax/libs/jquery/1.11.2/jquery.min.js"></script>
<script type="text/javascript"
src="https://www.google.com/jsapi?autoload={
'modules':[{
'name':'visualization',
'version':'1',
'packages':['corechart']
}]
}">
</script>
</head>
<body>
<div id="chart" style="width: 1500px; height: 700px"></div>
<script>
$(document).ready(function () {
var maxDataPoints = 10;
var chart = new google.visualization.LineChart($('#chart')[0]);
var data = google.visualization.arrayToDataTable([
['Time', 'Temperature'],
[getTime(), 0]
]);
var options = {
title: 'Temperature',
hAxis: {title: 'Time', titleTextStyle: {color: '#333'}}, //Added hAxis and vAxis label
vAxis: {title: 'TempValue', minValue: 0, titleTextStyle: {color: '#333'}},
curveType: 'function',
animation: {
duration: 1000,
easing: 'in'
},
legend: {position: 'bottom'}
};
function addDataPoint(dataPoint) {
if (data.getNumberOfRows() > maxDataPoints) {
data.removeRow(0);
}
data.addRow([getTime(), dataPoint.value]);
chart.draw(data, options);
}
function getTime() {
var d = new Date();
return d.toLocaleTimeString();
}
function doPoll() {
$.getJSON('http://localhost:8686/temperatureData',
function (result) {
addDataPoint(result);
setTimeout(doPoll, 10000);
});
}
doPoll();
});
</script>
</body>
</html>
What Should i do so that i can provide remotely visualization ? I want to provide remotely visualization in mobile and desktop/laptop browser.
Saurabh Just Follow Bellow Steps:
1) On the computer that is running the Microsoft Dynamics NAV Web Server components, on the Start menu, choose Control Panel, choose System and Security, and then choose Windows Firewall.
2) In the navigation pane, choose Advanced settings.
3) In the Windows Firewall with Advanced Settings window, in the navigation pane, choose Inbound Rules, and then in the Actions pane, choose New Rule.
4) On the Rule Type page, choose Port, and then choose the Next button.
5) On the Protocol and Ports page, choose Specific local ports, and then enter the port number. For example, enter 8080 for the default port of the Microsoft Dynamics NAV Web client.Choose the Next button.
6) On the Action page, choose Allow the connection, and then choose the Next button.
7)On the Profile page, choose the profiles, and then choose the Next button.
8) On the Name page, type a name for the rule, and then choose the Finish button.
Once you are done with above steps do port forwarding thorough your router.
Enjoy
CORS on ExpressJS
In your ExpressJS app on node.js, do the following with your routes:
app.use(function(req, res, next) {
res.header("Access-Control-Allow-Origin", "*");
res.header("Access-Control-Allow-Headers", "Origin, X-Requested-With, Content-Type, Accept");
next();
});
app.get('/', function(req, res, next) {
// Handle the get for this route
});
app.post('/', function(req, res, next) {
// Handle the post for this route
});
I'm moving my code to a server. This code works and renders database information perfectly on my own server I set up on localhost, however an error from index.html stating "io is not defined" displays when I run the code from my server. For whatever reason socket.io is not being recognized. Also, nothing is shown if I type in localhost:3000 in my browser. Any help would be greatly appreciated.
I have two files, server.js and index.html.
server.js:
var mysql = require('mysql')
var io = require('socket.io').listen(3000)
var db = mysql.createConnection({
host: '127.0.0.1', // Important to connect to localhost after connecting via ssh in screen
user: 'username',
password: '12345',
database: '12345',
port: 3306
})
// Log any errors connected to the db
db.connect(function(err){
if (err) console.log(err)
})
// Define/initialize our global vars
var notes = []
var isInitNotes = false
var socketCount = 0
//Socket.io code below
io.sockets.on('connection', function(socket){
// Socket has connected, increase socket count
socketCount++
// Let all sockets know how many are connected
io.sockets.emit('users connected', socketCount)
socket.on('disconnect', function() {
// Decrease the socket count on a disconnect, emit
socketCount--
io.sockets.emit('users connected', socketCount)
})
socket.on('new note', function(data){
// New note added, push to all sockets and insert into db
notes.push(data)
io.sockets.emit('new note', data)
// Use node's db injection format to filter incoming data
db.query('INSERT INTO notes (note) VALUES (?)', data.note)
})
console.log("10");
// Check to see if initial query/notes are set
if (! isInitNotes) {
// Initial app start, run db query
db.query('SELECT * FROM `Users`')
.on('result', function(data){
// Push results onto the notes array
//console.log(notes);
notes.push(data)
})
.on('end', function(){
// Only emit notes after query has been completed
socket.emit('initial notes', notes)
})
isInitNotes = true
} else {
// Initial notes already exist, send out
socket.emit('initial notes', notes)
}
})
index.html: (thinking the problem is in either the way I'm linking my socket.io.js file, or in the line of code where I declare the variable "socket")
<script src="http://ajax.googleapis.com/ajax/libs/jquery/1.10.2/jquery.min.js"></script>
<!-- Script below works with my server I set up on local host
<script src="http://localhost:3000/socket.io/socket.io.js"></script>-->
<!-- script below properly links to the socket.io.js file in my directory, and throws no errors-->
<script type= "node_modules/socket.io/node_modules/socket.io-client/socket.io.js"></script>
<script>
$(document).ready(function(){
var socket = io.connect('http://localhost:3000'); //LINE OF CODE IN QUESTION
//Code below not really relevant to problem, but still part of my project.
socket.on('initial notes', function(data){
var html = ''
for (var i = 0; i < data.length; i++){
// We store html as a var then add to DOM after for efficiency
html += '<li>' + data[i].Name + '</li>'
}
$('#notes').html(html)
})
// New note emitted, add it to our list of current notes
socket.on('new note', function(data){
$('#notes').append('<li>' + data.Name + '</li>')
})
// New socket connected, display new count on page
socket.on('users connected', function(data){
$('#usersConnected').html('Users connected: ' + data)
})
// Add a new (random) note, emit to server to let others know
$('#newNote').click(function(){
var newNote = 'This is a random ' + (Math.floor(Math.random() * 100) + 1) + ' note'
socket.emit('new note', {note: newNote})
})
})
</script>
<ul id="notes"></ul>
<div id="usersConnected"></div>
<div id="newNote">Create a new note:</div
SOLVED!
Figured it out. I used "script src="my servers ip address:3000/socket.io/socket.io.js" and then change the variable socket to var socket = io.connect('Servers ip address:3000'); So the answer was to take out localhost all together.
I believe there could be a problem loading Socket.io from your server if it works locally (perhaps a permissions issue?), try loading it from Socket.io CDN to test.
<script src="http://cdnjs.cloudflare.com/ajax/libs/socket.io/0.9.16/socket.io.min.js"></script>