Note: When I delete "node_modules\uws\uws_win32_59.node" it works fine. uws is used by engine.io, which is used by socket.io.
I wrote a very basic app to demo the problem. In the below app, with 2 tabs of the index.html open in chrome, clicking "emit" emits the message from the client, but takes a significant, variable amount of time to reach the server. Anywhere from 2-15+ seconds. If I only have 1 index.html page open, it works fine, but once a second one is opened, I encounter the problem. If I delete the above uws_win32_59.node, it works fine with multiple connections.
server.js:
var io = require('socket.io')();
io.on('connection', function(socket){
console.log('connection made');
socket.on('number', function(num) {
console.log(num + ' received on server');
io.emit('number', num);
console.log(num + ' emitted from server');
});
});
io.listen(9001);
index.html:
<html>
<head>
<script src="https://cdnjs.cloudflare.com/ajax/libs/socket.io/2.0.4/socket.io.js"></script>
</head>
<body>
<button id="emit">emit</button>
<p id="nums"></p>
<script>
var socket = io('http://localhost:9001');
socket.on('number', function(num){
console.log(num + ' received on client');
document.getElementById('nums').innerHTML = num;
});
var num = 0;
document.getElementById('emit').addEventListener('click', function(){
num++;
socket.emit('number', num);
console.log(num + ' emitted from client');
});
</script>
</body>
</html>
the default "npm install socket.io" installs that uws module mentioned above, which itself is used by engine.io.
run "node server" and open 2 instances of the index.html and click emit and notice the browser developer tools console logging and the node server console logging to recreate the issue.
EDIT: looks like there is an open issue with uws on windows os: https://github.com/socketio/socket.io/issues/3100
Maybe you need npm install socket.io#1.7.4. I think version 2.0 is significantly slower
Related
The assignment is about embedded system. We are learning how to use BeagleBone Black and how we can use it to make small-size devices e.g., devices that can measure temperature and pulse.
A part of our first assignment is to follow this guide: https://randomnerdtutorials.com/programming-the-beaglebone-black-with-bonescript/
We need to make a server in Node JS and a index in html. The site provides button to control a LED light that is connected to a breadboard via BeagleBone Black.
I have connected the LED, pins and wires to the BeagleBone Black. Installed Ubuntu 18.14, NodeJS, npm socket.io and Bonescript(Script dedicated to BeagleBone).
I am not using Cloud 9 IDE to run the server.js and index.html.
But I use terminal in Ubuntu.
To start the server i use this command: node server.js
I tried for several days to make the server and index.html to run,
but I get this error or nothing happends:
/home/ubuntu/bonescript/server.js:42
var io = require('socket.io').listen(server);
^
[TypeError: require(...).listen is not a function
at Object.<anonymous> (/home/ubuntu/bonescript/server.js:42:31)
at Module._compile (internal/modules/cjs/loader.js:1137:30)
at Object.Module._extensions..js (internal/modules/cjs/loader.js:1157:10)
at Module.load (internal/modules/cjs/loader.js:985:32)
at Function.Module._load (internal/modules/cjs/loader.js:878:14)
at Function.executeUserEntryPoint [as runMain] (internal/modules/run_main.js:71:12)
at internal/main/run_main_module.js:17:47
Can anyone help me pinpoint the problem? I am really stuck on this stage. Thanks.
index.html code:
<!DOCTYPE html>
<html>
<head>
<title>Home Automation Web Server with BeagleBone</title>
<script src = "/socket.io/socket.io.js" ></script>
<script>
// Establishing connection with server
var socket = io.connect();
// Changes the led state
function changeState(state){
if (state==1){
// Emit message changing the state to 1
socket.emit('changeState', '{"state":1}');
// Change led status on web page to ON
document.getElementById("outputStatus").innerHTML = "Status: ON";
}
else if (state==0){
// Emit message changing the state to 0
socket.emit('changeState', '{"state":0}');
// Change led status on web page to OFF
document.getElementById("outputStatus").innerHTML = "Status: OFF";
}
}
</script>
</head>
<h2>LED</h2>
<p id="outputStatus">Status</p>
<button type="button" onclick="changeState(1);">ON</button>
<button type="button" onclick="changeState(0);">OFF</button>
</div>
</body>
</html>
server.js code:
//Loading modules
var http = require('http');
var fs = require('fs');
var path = require('path');
var b = require('bonescript');
// Create a variable called led, which refers to P9_14
var led = "P9_14";
// Initialize the led as an OUTPUT
b.pinMode(led, b.OUTPUT);
// Initialize the server on port 8888
var server = http.createServer(function (req, res) {
// requesting files
var file = '.'+((req.url=='/')?'/index.html':req.url);
var fileExtension = path.extname(file);
var contentType = 'text/html';
// Uncoment if you want to add css to your web page
/*
if(fileExtension == '.css'){
contentType = 'text/css';
}*/
fs.exists(file, function(exists){
if(exists){
fs.readFile(file, function(error, content){
if(!error){
// Page found, write content
res.writeHead(200,{'content-type':contentType});
res.end(content);
}
})
}
else{
// Page not found
res.writeHead(404);
res.end('Page not found');
}
})
}).listen(8888);
// Loading socket io module
var io = require('socket.io').listen(server);
// When communication is established
io.on('connection', function (socket) {
socket.on('changeState', handleChangeState);
});
// Change led state when a button is pressed
function handleChangeState(data) {
var newData = JSON.parse(data);
console.log("LED = " + newData.state);
// turns the LED ON or OFF
b.digitalWrite(led, newData.state);
}
// Displaying a console message for user feedback
server.listen(console.log("Server Running ..."));
I have same problem but solve it already the code on this website is based on older node version, you have to change the code on line
var io = require('socket.io').listen(server);
to
var io = require('socket.io')(server);
and edit variable or remove this line since newer node cant use .listen function twice (the code already use it on server var to open port 8888)
server.listen(console.log("Server Running ..."));
socket.io is an internal library, not an external one. Therefore, when you ran npm install socket.io, you downloaded something that is not the socket.io that you want.
Delete your node_modules, and remove socket.io from package.json, and reinstall bonescript via npm install. Then it should work.
I'm trying to play around with node webkits hotkey example which can be viewed on their Shortcut's page here: https://github.com/nwjs/nw.js/wiki/Shortcut
Here's my code:
test.js
// Load native UI library.
var gui = window.require('nw.gui');
var option = {
key : "Ctrl+Shift+A",
active : function() {
console.log("Global desktop keyboard shortcut: " + this.key + " active.");
},
failed : function(msg) {
// :(, fail to register the |key| or couldn't parse the |key|.
console.log(msg);
}
};
// Create a shortcut with |option|.
var shortcut = new gui.Shortcut(option);
// Register global desktop shortcut, which can work without focus.
gui.App.registerGlobalHotKey(shortcut);
// If register |shortcut| successfully and user struck "Ctrl+Shift+A", |shortcut|
// will get an "active" event.
// You can also add listener to shortcut's active and failed event.
shortcut.on('active', function() {
console.log("Global desktop keyboard shortcut: " + this.key + " active.");
});
shortcut.on('failed', function(msg) {
console.log(msg);
});
// Unregister the global desktop shortcut.
gui.App.unregisterGlobalHotKey(shortcut);
index.html
<!DOCTYPE html>
<html>
<head>
<title>Hello World!</title>
<script>
require("./test.js");
</script>
</head>
<body>
<h1>Hello World!</h1>
We are using node.js <script>document.write(process.version)</script>.
</body>
</html>
package.json
{
"name": "nw-demo",
"main": "index.html",
"dependencies": {
"nw": "^0.12.0"
},
"scripts": {
"start": "nw"
}
}
It breaks at this line on test.js saying undefined is not a function.
var shortcut = new gui.Shortcut(option);
Just remove this line:
gui.App.unregisterGlobalHotKey(shortcut);
In your code you register it, then delete. It working well for me (mac, nwjs 0.12)
As shaynem in (https://github.com/nwjs/nw.js/issues/3263#issuecomment-89679115) points out you should be running at least node-webkit >= 0.10.0
You should make sure your PATH (or the build tool you're using, e.g. nodebob) is not referencing any old leftover versions of node-webkit after you upgrade.
Also if you're on Ubuntu, you might stumble upon an open issue (https://github.com/nwjs/nw.js/issues/3199)
note webkit 0.13.0 has a bug where the the k is lowercase even though the method is documented with an uppercase K. Try:
registerGlobalHotkey(shortcut);
to verify this bug exists do:
var util = require('util');
console.log(util.inspect(nw.App));
I am attempting to pipe the stdout & stdin of a child_process to a browser & display it in an html page. I am using browserify to get node.js to run on the browser. My code for spawning the child_process is like this.
var child = require('child_process');
var myREPL = child.spawn('myshell.exe', ['args']);
// myREPL.stdout.pipe(process.stdout, { end: false });
process.stdin.resume();
process.stdin.pipe(myREPL.stdin, { end: false });
myREPL.stdin.on('end', function() {
process.stdout.write('REPL stream ended.');
});
myREPL.on('exit', function (code) {
process.exit(code);
});
myREPL.stdout.on('data', function(data) {
console.log('\n\nSTDOUT: \n');
console.log('**************************');
console.log('' + data);
console.log('==========================');
});
I created a bundle.js using browserify and my html looks like this.
<!doctype html>
<html lang="en">
<head>
<meta charset="utf-8" />
<title></title>
<!--[if IE]>
<script src="http://html5shiv.googlecode.com/svn/trunk/html5.js"></script>
<![endif]-->
<script src="bundle.js"></script>
<script src="main.js"></script>
</head>
<body>
</body>
</html>
I am trying to avoid running an http server and piping the results to it in the browser. Is there any other way where I can do it ?
Thanks
You should look into hyperwatch, which pipes the server side stdout/stderr to the browser and renders it exactly like it would appear in your terminal (including colors).
If it doesn't exactly solve your problem, reading through the code should at least help you. It uses hypernal under the hood in order to convert terminal output to html.
I dont know if this is to late but i managed to run a program from browser starting from this code that works only on linux (i use ubuntu). You will have to run interactive programs with stdbuf -o0 prefix.
var child = require('child_process');
var myREPL = child.spawn('bash');
process.stdin.pipe(myREPL.stdin);
myREPL.stdin.on("end", function() {
process.exit(0);
});
myREPL.stdout.on('data', function (data) {
console.log(data+'');
});
myREPL.stderr.on('data', function (data) {
console.log('stderr: ' + data);
});
An then to make it to work on browser you only need to add socket.io
var myREPL = child.spawn(program);
myREPL.stdin.on("end", function() {
socket.emit('consoleProgramEnded');
});
myREPL.stdout.on('data', function (data) {
socket.emit('consoleWrite',data+'');
});
myREPL.stderr.on('data', function (data) {
socket.emit('consoleWrite',data+'');
});
socket.on('consoleRead',function(message){
console.log("Writing to console:"+message);
myREPL.stdin.write(message.replace("<br>","")+"\n");
});
I hope that will help you.
I think the frontail NPM module can also do what you want to do -
https://github.com/mthenw/frontail
I have used it and it works
I have a Node application where I want to use socket.io to communicate data to a client where it is displayed by smoothie. I have both packages installed (via NPM) on two different node environments and in both cases in the node_modules sub-directory of my project. One of the environments is the BeagleBone Black and the other is the Cloud9 IDE environment. In both cases the socket.io module resolves and works fine but no combination of path names gets the smoothie module to resolve (which I can get to work if I just pull it from GitHub directly).
Here are the relevant bits of the server side code for the Cloud9 IDE:
var app = require('http').createServer(handler)
, io = require('socket.io').listen(app)
, fs = require('fs')
app.listen(process.env.PORT, process.env.IP);
function handler (req, res) {
fs.readFile(__dirname + '/NotWorking.html',
function (err, data) {
if (err) {
res.writeHead(500);
return res.end('Error loading index.html');
}
res.writeHead(200);
res.end(data);
});
}
.
.
.
Here are the relevant bits from the client side:
<!DOCTYPE html>
<html>
<head>
<script src="smoothie/smoothie.js"></script>
<script src="socket.io/socket.io.js"></script>
<script>
var line1 = new TimeSeries();
var line2 = new TimeSeries();
var socket = io.connect('http://demo-project.wisar.c9.io/');
socket.on('news', function (data) {
for (var property in data) {
dataPoint = data[property];
}
line1.append(new Date().getTime(), dataPoint);
line2.append(new Date().getTime(), 40);
socket.emit('my other event', { my: dataPoint });
});
</script>
.
.
.
As I said, both modules are located in the node_modules sub directory of the project directory where the above scripts live. The node documentation describes how includes are supposed to be resolved (http://nodejs.org/api/modules.html#modules_all_together) and I think that I can follow the path to how it resolves the link to socket.io by way of the index.js route...but it also works when I put a "/" in front which I can not find a path for. No permutation or combination of paths makes the smoothie module resolve. smoothie, btw, is a small charting application that can be found in npm under that name.
Any help would be appreciated.
If your current file is in the same directory as node_modules, then to load smoothie try this path in src of script tag:
./node_modules/smoothie/smoothie.js
The path smoothie/smoothie.js is not giving the location of smoothie.js, which lies in node_modules/smoothie/smoothie.js. This worked for me, I hope this works for you.
codes in file main.js is like this:
phantom.injectJs("libs/require-1.0.7.js");
require.config(
{
baseUrl: ""
}
);
require([], function(){});
when i run "phantomjs main.js" in the commandline, requirejs doesn't work well in the main.js. I know how to use requirejs in the page running in the browser(including phantomjs' way: page.open(url, callback)), but not like above. I tries using requirejs like the main.js, it is a popular problem, i think. Thank you!
I just struggled for some time. My solution is not clean, but it works, and I'm happy with that due to the unfinished api documentation from phantomjs.
Wordy explanation
You need three files. One is your amd phantomjs test file which I'll call "amd.js". The second is your html page to load which I'll name "amd.html". Finally the browser test which I called "amdTestModule.js".
In amd.html, declare your script tag per normal:
<script data-main="amdTestModule.js" src="require.js"></script>
In your phantomjs test file, this is where it gets hacky. Create your page, and load in the 'fs' module. This allows you to open a relative file path.
var page = require('webpage').create();
var fs = require('fs');
page.open('file://' + fs.absolute('tests/amd.html'));
Now since requirejs loads files asynchronously, we can't just pass in a callback into page.open and expect things to go smoothly. We need some way to either
1) Test our module in the browser and communicate the result back to our phantomjs context. Or
2) Tell our phantomjs context that upon loading all the resources, to run a test.
#1 was simpler for my case. I accomplished this via:
page.onConsoleMessage = function(msg) {
msg = msg.split('=');
if (msg[1] === 'success') {
console.log('amd test successful');
} else {
console.log('amd test failed');
}
phantom.exit();
};
**See full code below for my console.log message.
Now phantomjs apparently has an event api built in but it is undocumented. I was also successfully able to get request/response messages from their page.onResourceReceived and page.onResourceRequested - meaning you can debug when all your required modules are loaded. To communicate my test result however, I just used console.log.
Now what happens if the console.log message is never ran? The only way I could think of resolving this was to use setTimeout
setTimeout(function() {
console.log('amd test failed - timeout');
phantom.exit();
}, 500);
That should do it!
Full Code
directory structure
/projectRoot
/tests
- amd.js
- amdTestModule.js
- amd.html
- require.js (which I symlinked)
- <dependencies> (also symlinked)
amd.js
'use strict';
var page = require('webpage').create();
var fs = require('fs');
/*
page.onResourceRequested = function(req) {
console.log('\n');
console.log('REQUEST');
console.log(JSON.stringify(req, null, 4));
console.log('\n');
};
page.onResourceReceived = function(response) {
console.log('\n');
console.log('RESPONSE');
console.log('Response (#' + response.id + ', stage "' + response.stage + '"): ' + JSON.stringify(response, null, 4));
console.log('\n');
};
*/
page.onConsoleMessage = function(msg) {
msg = msg.split('=');
if (msg[1] === 'success') {
console.log('amd test successful');
} else {
console.log('amd test failed');
}
phantom.exit();
};
page.open('file://' + fs.absolute('tests/amd.html'));
setTimeout(function() {
console.log('amd test failed - timeout');
phantom.exit();
}, 500);
amd.html
<!DOCTYPE html>
<html>
<head>
<meta charset="UTF-8">
</head>
<body>
<script data-main='amdTestModule.js' src='require.js'></script>
</body>
</html>
amdTestModule.js
require([<dependencies>], function(<dependencies>) {
...
console.log(
(<test>) ? "test=success" : "test=failed"
);
});
console
$ phantomjs tests/amd.js
amd test successful
you are misunderstanding webpage.injectJs()
it's for injecting scripts into the page you are loading, not into the phantomjs runtime environment.
So using .injectJs() is making requirejs load up into your page, not into phantomjs.exe.
That said, phantomjs's runtime environment has an aproximation of commonjs. RequireJs will not run on there by default. If you felt especially (VERY) motivated, you could attempt porting the require-shim made for nodejs, but it doesn't work out of the box, and would require an incredibly deep understanding of the runtimes. for more details: http://requirejs.org/docs/node.html
a better idea:
probably you should make sure you have commonjs versions of your javascript you wish to run. i personally write my code in typescript so i can build for either commonjs or amd. i use commonjs for phantomjs code, and amd for nodejs and browser.