I have trouble understanding the reason for the error I get when the user tries to write anything to the server:
TypeError: Object #<identifyClient> has no method 'write'
at writeToAll (/root/node/mud/server.js:13:15)
Why does identifyClient() complaints about the write(), while it happens in the writeToAll() (line 15 has comment next to it)? identifyClient() really only sets the name for the client, and should not be concerned what happens in the writeToAll().
var net = require("net");
var clients = [];
function identifyClient(client) {
this.name = null;
this.client = client;
}
function writeToAll(data, client) {
for (var i = 0; i < clients.length; i++) {
if (clients[i] != client) {
clients[i].write(data); // This is line 15
}
}
}
var server = net.createServer(function(client) {
var clientID = new identifyClient(client);
clients.push(clientID);
client.on("data", function(data) {
writeToAll(data, client);
});
});
server.listen(4444);
Replace clients[i] with clients[i].client
also you have to remove the client from the clients array once it disconnects.
Related
[Sorry for my bad English]
Hi!
I have to communicate between a node.js application [client side] and c# application [server side].
Each side sends pings to the other, on TCP protocol.
I Successed to create both client and server side, but I have to problems:
after the first ping from the client to the server, the client throws an error:
This socket has been ended by the other party
What i'm doing wrong?
The server reads the incomeing pings into a large buffer.
When I decode it to string, I get string with length of 4096.
How I read the excact message length?
This is the server side code: [c#, .NET 6]
using System.Net;
using System.Net.Sockets;
using System.Text;
Console.WriteLine("Start...");
CancellationTokenSource cts = new();
TcpListener listener = new(IPAddress.Any, 11111);
try
{
listener.Start();
Console.WriteLine("Listining...");
var clientCounter = 0;
var ct = cts.Token;
while (!ct.IsCancellationRequested)
{
using TcpClient client = await listener.AcceptTcpClientAsync(ct)
.ConfigureAwait(false);
using NetworkStream stream = client.GetStream();
_ = PrintUploadedData(stream, ct);
_ = PushData(stream, ct);
clientCounter++;
Console.WriteLine("New client ({0}) connected", clientCounter);
}
}
finally
{
cts.Cancel();
listener.Stop();
}
async Task PrintUploadedData(NetworkStream stream, CancellationToken ct)
{
var buf = new byte[4096];
while (!ct.IsCancellationRequested)
{
var timeout = CancellationTokenSource.CreateLinkedTokenSource(
ct,
new CancellationTokenSource(TimeSpan.FromMinutes(3)).Token);
try
{
var amountRead = await stream.ReadAsync(buf, timeout.Token);
if (timeout.IsCancellationRequested)
{
Console.Error.WriteLine("No Message.");
break;
}
if (amountRead == 0) break; //end of stream.
var message = Encoding.UTF8.GetString(buf);
Console.WriteLine(message);
}
catch (OperationCanceledException)
{
Console.Error.WriteLine("Time out");
break;
}
}
}
async Task PushData(NetworkStream stream, CancellationToken ct)
{
while (!ct.IsCancellationRequested)
{
var messageToSend = DateTime.Now.TimeOfDay.ToString();
var messageBytes = Encoding.UTF8.GetBytes(messageToSend);
await stream.WriteAsync(messageBytes, ct).ConfigureAwait(false);
await Task.Delay(TimeSpan.FromSeconds(15), ct);
}
}
And the client side code [node.js]:
import { Socket } from 'net';
var client = new Socket();
client.on('connect', () => console.log("CONNECTED"));
client.on('data', data => console.log("data", data.toString()));
client.on('error', err => console.error(err));
client.connect(11111, "127.0.0.1");
printMessages();
async function printMessages() {
for (let i = 0; i < 10; i++) {
client.write('Ping ' + i);
await sleep(4000);
}
}
function sleep(ms) {
return new Promise(resolve => setTimeout(resolve, ms));
}
I am building a messenger bot in node. I want it to collect user input data and have a conversation or ask questions, but the code I have doesn't work. the part that does not work is it only continues to the next else if block if i type the same code. and second the array is not capturing the text after the first if statement. Is there a better way to do it? Could someone provide code?
My code is below. what i want is like in this iimage:
var currentbot = 0;
var awnswers = [];
app.post('/webhook', function(req, res) {
var events = req.body.entry[0].messaging;
for (i = 0; i < events.length; i++) {
var event = events[i];
if (event.message && event.message.text) {
var text = event.message.text;
if (text == "hi") {
start(event.message.text, event.sender.id);
}
}
}
res.sendStatus(200);
});
var awnswers = [];
function start(text, id) {
if (count == 0) {
sendTextMessage('hello lets order!', id);
arr.push(text);
console.log(awnswers);
count = 1;
} else if (count == 1) {
sendTextMessage('what size do you want?', id);
arr.push(text);
console.log(awnswers);
count = 2;
} else if (count == 2) {
sendTextMessage('its on its way!', id);
arr.push(text);
console.log(awnswers);
count = 0;
}
}
function sendTextMessage(messageText, recipientId) {
var messageData = {
recipient: {
id: recipientId
},
message: {
text: messageText
}
};
callSendAPI(messageData);
}
function callSendAPI(messageData) {
request({
uri: 'https://graph.facebook.com/v2.6/me/messages',
qs: {
access_token: process.env.access_token
},
method: 'POST',
json: messageData
}, function(error, response, body) {
if (!error && response.statusCode == 200) {
var recipientId = body.recipient_id;
var messageId = body.message_id;
console.log("Successfully sent generic message with id %s to recipient %s", messageId, recipientId);
} else {
console.error("Unable to send message.");
console.error(response);
console.error(error);
}
});
}
The main issues I think I see are:
Start() is only called when text == hi
Count is not defined
You're pushing to the array 'arr' not, awnswers
You can fix these by:
Calling start() on every message
Defining count like var count = 0; at the top of your file, next to var currentbot
awnswers.push(text);
I have this code
it('This should pass anyway', function (done) {
testObj.testIt(regStr);
});
testObj
this.testIt = function (regStr) {
selector.count().then(function (orgCount) {
for (var curr = 0; curr < count; curr++) {
checkField(curr, regStr);
}
});
};
function checkField(curr, regStr) {
selector.get(curr).all(by.tagName('li')).get(0).getInnerHtml().then(function (text) {
expect(text).to.match(regStr, curr + '#ERR');
});
}
If one of these expects get a failure, test fails. How can i handle this? I mean - can i somehow count passed and failed expect()ations and return it? or, at least, dont let test break on first error.
I've tried try-catch, but nothing good happened.
it('This should pass anyway', function (done) {
try {
testObj.testIt(regStr);
} catch (e) {
console.log('#err' + e);
}
});
And then i wanted to use done(), but havent found any examples to do the similar. Can u please help me?
Sry for my english
UPD
You can return either null or a string from checkField(), join them up, and expect the array to be empty:
this.testIt = function (regStr) {
selector.count().then(function (orgCount) {
var errors = [];
for (var curr = 0; curr < orgCount; curr++) {
var e = checkField(curr, regStr);
if (e) { errors.push(e); }
}
assert.equal(0, errors.length, errors);
});
};
A cleaner approach would be to use map() to collect the data into an array:
var data = selector.map(function (elm) {
return elm.element(by.tagName('li')).getText();
});
expect(data).toEqual(["test1", "test2", "test3"]);
I was creating a chrome extension in which i am using chrome.socket.udp. I am following this tutorial but i don't see any data sent.
This is my code..
//var socketId;
var address = "127.0.0.1";
var port = 6454;
function str2ab(str) {
var buf = new ArrayBuffer(str.length*2);
var bufView = new Uint16Array(buf);
for (var i=0, strLen=str.length; i<strLen; i++) {
bufView[i] = str.charCodeAt(i);
}
return bufView;
}
function sendPackets(){
console.log("sending packets");
chrome.sockets.udp.create({}, function(socketInfo) {
// The socket is created, now we can send some data
var socketId = socketInfo.socketId;
console.log(socketId);
chrome.sockets.udp.send(socketId, str2ab("hello"),
'127.0.0.1', 1337, function(sendInfo) {
console.log("packets sent");
console.log("sent " + sendInfo.bytesSent);
});
});
}
document.getElementById('send').addEventListener('click', sendPackets);
this is the output i am getting in console...
sending packets background.js:16
165 background.js:20
And there is no sign of sent data ....plz help...
I'm writing a web application that is to be used by only one client and want to accept only one connection to the server. The LAN will be confined to an aircraft. I'm really new to Dart, HTML etc. How can I refuse multiple connections to the server?
Here's my code fir the HTTP server -
class MicroServer {
var address;
var port;
var httpServer; // global
MicroServer(this.address, this.port) {
final HTTP_ROOT_PATH = Platform.script.resolve('../build/web').toFilePath();
final virDir = new VirtualDirectory(HTTP_ROOT_PATH)
..jailRoot = false
..allowDirectoryListing = true;
HttpServer.bind(address, port)
.then((httpserver) {
httpServer = httpserver;
httpserver.listen((request) {
virDir.serveRequest(request);
});
});
}
}
Dart is single-threaded, so you can safely use check a variable to see if there's a current connection:
bool hasClient = false;
HttpServer.bind(address, port)
.then((httpserver) {
httpServer = httpserver;
httpserver.listen((request) {
if (hasClient) {
sendBusyPage(request);
} else {
hasClient = true;
virDir.serveRequest(request);
hasClient = false;
}
});
});
}
I have found that the code below works so far. I could also have taken advantage of
if(request.session.isNew) // then grab the session.id etc.
but it's just as easy to use the session.id variable since I will use it anyway.
class MicroServer {
var address;
var port;
var httpServer;
var sessionID; // null until first request received
MicroServer(this.address, this.port) {
final HTTP_ROOT_PATH = Platform.script.resolve('../build/web').toFilePath();
final virDir = new VirtualDirectory(HTTP_ROOT_PATH)
..jailRoot = false // process links will work
..followLinks = true
..allowDirectoryListing = true;
HttpServer.bind(address, port)
.then((httpserver) {
httpServer = httpserver;
httpserver.idleTimeout = null;
print("micro server started on ${httpserver.address}:${httpserver.port}");
httpserver.listen((request) {
if(sessionID == null) {
sessionID = request.session.id;
virDir.serveRequest(request);
} else if(sessionID == request.session.id){
virDir.serveRequest(request);
} else {
request.response.writeln('ERROR - Connection is in use.');
request.response.close();
request.session.destroy();
}
});
}).catchError((e) => print(e.toString()));
}
}