Develop Reference

Try to connect to a server with Google Assistance App

I need to send data out from my google assistance app to a database. In order to do this, I've created a server that takes the data, packages it, and then sends it out. I have the hostname and port and it works in a normal javascript/node.js program but when I use it in my google assistant app nothing happens. I tried figuring out the problem and it looks like the code just isn't connecting. The code I'm using to send data to the server is as follows:
function sendData(app){
var net = require('net');
var message = {"test": 200};
var thisMessage = JSON.stringify(message);
var client = new net.Socket();
client.connect(<port>, '<hostname>', function() {
app.tell(JSON.stringify(client.address()));
console.log('Connected');
client.write(thisMessage);
});
client.on('data', function(data) {
console.log('Received: ' + data);
client.destroy();
});
client.on('close', function() {
console.log('Connection closed');
});
return 0;
}
(NOTE: Port and hostname left out for privacy purposes)
This completely skips over the app.tell, leading me to believe the connection is never made. I know it works asynchronously with the server, however, I don't understand why it isn't connecting whatsoever.
I have tried it both in simulation and on my smartphone with sandbox on and off. Is there a better way to connect? Note that the server I'm connecting to is python-based.

The problem is likely that you're running it on Cloud Functions for Firebase which has a limit on outbound connections under their free "Spark" plan. With this plan, you can only connect to other Google services. This is usually a good way to start understanding how to handle Action requests, but has limitations. To access endpoints outside of Google, you need to upgrade to either their "Flame" fixed price plan or "Blaze" pay-as-you-go plan.
You do not, however, need to run on Google's servers or need to use node.js. All you need is a public HTTPS server with a valid SSL cert. If you are familiar with JSON, you can use any programming language to handle the request and response. If you are familiar with node.js, you just need a node.js server that can create Express request and response objects.

Running a node.js file from website

I have recently started using the Twilio platform to send SMS to my users. I am perfectly able to run the node.js file from the node terminal with the command:
node twilio.js
Now, my goal is to be able to send those SMS, but from my website. For instance, when the user provides his phone number and presses the "Send sms" button. How can I achieve this? I have been looking this up for a while and I came across Express platform, ajax post requests, http server, etc. But, I can't figure out how to use them. I currently make many ajax requests (POST and GET) on my site, but I'm not able to make a request to a node file.
Thanks in advance,
Here is the twilio.js file:
// Twilio Credentials
var accountSid = 'ACCOUNT SID';
var authToken = 'ACCOUNT TOKEN';
//require the Twilio module and create a REST client
var client = require('twilio')(accountSid, authToken);
client.messages.create({
to: 'TO',
from: 'FROM',
body: 'Message sent from Twilio!',
}, function (err, message) {
console.log(message.sid);
});

Being able to run any arbitrary script on your server from a webpage would be a huge security risk - don't do that. I'm not sure where you're hosting your site, or what technology stack you're running your site on, but since you mentioned Express and Node -- if you're using Express I'd recommend that you setup a route that handles an ajax request. When someone presses 'Send SMS' you send an ajax request to that route, and in the handler that gets invoked you place the Twilio logic.

Here is a very simple way to setup an Express request that calls you node module:
twilio.js:
// Twilio Credentials
var accountSid = 'ACCOUNT SID';
var authToken = 'ACCOUNT TOKEN';
//require the Twilio module and create a REST client
var client = require('twilio')(accountSid, authToken);
function sendSms(callback) {
client.messages.create({
to: 'TO',
from: 'FROM',
body: 'Message sent from Twilio!',
}, callback);
}
// Export this function as a node module so that you can require it elsewhere
module.exports = sendSms;
Here is a good start for Express.
server.js:
var express = require('express');
var app = express();
// Requiring that function that you exported
var twilio = require('/path/to/twilio.js');
// Creating a controller for the get request: localhost:8081/send/sms
app.get('/send/sms', function (req, res) {
twilio(function(err, message) {
if (err) res.send(err);
res.send('Message sent: ' + message);
});
});
// Creating an HTTP server that listens on port 8081 (localhost:8081)
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);
});
Then you can run node server.js, go to your browser and go to the url: localhost:8081/send/sms and your message will be sent :)

I'd make it so the client sends a HTTP POST request to the server, and then the server will send the message on behalf of the client.
Easiest way is to use express. I'm a bit unsure of how you're serving your website from a Node.js app without using express. Do you have a custom solution or only a non-connected from end, or something like heroku or something? In any case, you can create a route that processes posts with the following:
app.post("send_twilio_message_route", function(req,res){
// this receives the post request -- process here
});
^ Note that doesn't actually create the express app. See my link below and they give examples of some of the nitty gritty and syntax.
So the above would be on the server, in your Node.js app. From the front-end client code that runs in the browser, you need to create a post. The easiest way and most likely way to do it is through $.post in Jquery. if you are using Angular there's a slightly different syntax but it's the same idea. You call post, point it to a url, and put in the body data.
Make the body of the post request contain data such the message, phone numbers,
authentication token maybe.
See this to be able to get the body from a post request and some more implementation details of how to set it up:
How to retrieve POST query parameters?
Depending on the nature of what you're doing you might consider having the sms processing stuff run separate from the actual web service. I would create the sms unique stuff as its own module and have a function retrieve the router so that you can mount is onto the app and move it about later. This might be overkill if you're doing something small, but I'm basically encouraging you to at the start put thought into isolating your services of your website, else you will create a mess. That being said, if it's just a small thing and just for you it might not matter. Depends on your needs.
Important: I highly encourage you to think about the malicious user aka me. If you don't add any authentication in the post body (or you could include it in the url but I wouldn't do that although it's equivalent), a malicious client could totally be a jerk and expend all of your twilio resources. So once you get it basic up in running, before deploying it to anything that people will see it, I recommend you add authentication and rate limiting.

How to send chat messages using converse library

I am using openfire as an XMPP server and using converse as client library. I want to send a chat message from my chat window to openfire. For this I want to send the text to a converse method which will send the message to the XMPP server.
I am trying to send the message using the following:
var msg = converse.env.$msg({
from: 'a1#localhost',
to: 'a6#localhost',
type: 'chat',
body: "Hi"
});
converse.send(msg);
But this sends the following frame in network of console in websocket:
message from='a1#localhost' to='a6#localhost' type='chat' body='Hi' xmlns='jabber:client'/>
This does not transfer message to the other user neither it stores it in the table. I am pretty much sure I am calling a wrong function. Can anyone povide any help.

You are calling the right function.
What you'll probably miss:
Listener of messages in "a6#localhost" client: as I read in documentation there are few functions
Probably, the right name of server. "localhost" has problem. You can
check Openfire for real service name on his own web panel
To check if a message it's delivered in Openfire you'll can check
OF's log (check debug one, but probably you'll have to enable it).
Real time messages are not stored on database, only groupchat's ones
and not everytime AND offline messages. To not find them on db means nothing
https://conversejs.org/docs/html/development.html
converse.chats.open('buddy#example.com');
converse.chats.get('buddy#example.com');
converse.listen.on('message', function (event, messageXML) { ... });

The syntax is wrong. conversejs uses strophe plugin to construct and send messages. It exposes the strophe $msg message builder for constructing stanzas. It has to be in the following format:
converse.env.$msg({from: 'a1#localhost', to: 'a6#localhost', type: 'chat'}).c('body').t('Hi');
You need to add a body node and within it a text node for the message.
You can also create and add your own api method and internally create a method that sends your custom stanza, and expose it using the api.

SignalR - connect to websocket service from javascript without SignalR library

I have a small SignalR project that I've started that right now all it does is receives a string and echo it back to all connected users.
What I'm wondering is, since SignalR open websockets on my server - how can I connect to the service using regular websockets javascript code? (I have a reason for wanting to do it that way without the SignalR library).
I've watched using chrome developer tools and I found that the address the browser is connecting to is:
ws://localhost:53675/signalr/connect?transport=webSockets&clientProtocol=1.4&connectionToken=YKgNxA6dhmtHya1srzPPIv6KFIYEjLTFOogXqcjPErFcKCmRdjvS2X6A2KmraW%2BrLnRUNf68gYPdOkOOgJ8yRcq4iCDm%2BbUyLejsr2NySNZBvLloWuMIAvgI6oC%2Fyt%2Ba&connectionData=%5B%7B%22name%22%3A%22ophirhubtest%22%7D%5D&tid=7
How do I generate the token?
Then, it seems that the messages going between the client and server are just regular json formatted text (which will be easy to mimic):
{"C":"d-9E7D682A-A,1|E,0|F,1|G,0","S":1,"M":[]}
{"H":"ophirhubtest","M":"Echo","A":["test"],"I":0}
{"C":"d-9E7D682A-A,2|E,0|F,1|G,0","M":[{"H":"ophirHubTest","M":"printEcho","A":["You said: test"]}]}
If I just try to connect than it connects but the connection is quickly closed. If I remove the token it closes immediately.
Is it possible to connect to the WS "manually" ?

Before you can connect to the server there is connection negotiation happening. This is when the server sends all the data needed to send and receive messages. Without connection negotiation you won't be able to connect to the server. Once you implement connection negotiation you will be probably half into implementing a SignalR client. I wrote a blog post describing SignalR protocol which should help you understand how things works underneath and why connecting to the server with your own websocket is not straightforward (or simply impossible if you don't follow the SignalR protocol).
EDIT
The ASP.NET Core version of SignalR now allows connecting to the server with bare webSocket.

I just want to add a that it is possible to connect to ASP.NET Core version of SignalR with websocket but you have to add the magic char 30 at the end of every call you make
const endChar = String.fromCharCode(30);
socket.send(`{"arguments":["arg1"],"streamIds":[],"target":"TestMethod","type":1}${endChar}`);

Great answers by Frédéric Thibault but there is one important thing missing. You need to send the protocol and the version directly after connecting. Otherwise you will get the error:
An unexpected error occurred during connection handshake.
Here is a full working example on how to use signalR with plain JavaScript and WebSockets:
let socket = new WebSocket("wss://your-url");
socket.onopen = function(e) {
console.log("[open] Connection established");
const endChar = String.fromCharCode(30);
// send the protocol & version
socket.send(`{"protocol":"json","version":1}${endChar}`);
};
socket.onmessage = function(event) {
console.log(`[message] Data received from server: ${event.data}`);
// parse server data
const serverData = event.data.substring(0, event.data.length - 1);
// after sending the protocol & version subscribe to your method(s)
if (serverData === "{}") {
const endChar = String.fromCharCode(30);
socket.send(`{"arguments":[],"invocationId":"0","target":"Your-Method","type":1}${endChar}`);
return;
}
// handle server messages
};
socket.onclose = function(event) {
if (event.wasClean) {
console.log(`[close] Connection closed cleanly, code=${event.code} reason=${event.reason}`);
} else {
console.log('[close] Connection died');
}
};
socket.onerror = function(error) {
console.log(`[error] ${error.message}`);
};

Websocket connection - no valid credentials

I'm trying to create a simple nodejs application that connects to the pathofexile.com/trade api.
The problem with this API is that is that you cannot use it unless you're logged in on the main website (my code works in the browser, but I'm trying to make it into a desktop application). There are several other applications that solves this issue by creating a session ID cookie with a users session ID (ID that you can get by logging in to the website). Unfortunately the documentation of the API is very limited and I havn't been able to find any information on how I can create/use the cookie as needed.
If I try to connect to the websocket, without being logged in to the main pathofexile website, I get the following error:
VM58:1 WebSocket connection to 'wss://www.pathofexile.com/api/trade/live/Metamorph/e602K4cL' failed: HTTP Authentication failed; no valid credentials available
I've tried using my sessionID to create a cookie like this by using the built in features in node:
const cookie = { name: 'POESESSID', value: '3acbf42fb842aasdqwe1a0c355f',domain:
'.pathofexile.com' }
session.defaultSession.cookies.set(cookie)
.then(() => {
// success
console.log("Cookie set (?)")
}, (error) => {
console.error(error)
})
Unfortunately, this does not work. I'm very unfamiliar with websockets (only started playing around with any of this a few days ago by accident), and I'm even less familiar with how websockets access and get data from cookies.
I've tried other modules like npm cookie-parser, npm request and npm needle to no avail.
The closest I've gotten to an answer is from a one year old reddit post where the user used C# to get this to work.
This is the code used in that example:
// Setup HTTP connection
HttpClientHandler handler = new HttpClientHandler();
CookieContainer cookieContainer = new CookieContainer();
cookieContainer.Add(composeUrl, new Cookie("POESESSID", sessionId));
handler.CookieContainer = cookieContainer;
HttpClient client = new HttpClient(handler);
If someone could help shine some light on this I'd be very appreciative. I understand that this question is incredibly niche and perhaps I'm asking it in the wrong forum, but I really don't know where to turn.
Appreciate any help!
//Alex