I am trying to make a communication between the server and the client (client is an html webpage which is locally installed on their computer) and that the client will request data from the server by its own name known to the internet (like a web domain) since my server will only handle data and not really be a website.
Note: My server will be a hosted web server since i don't want to use my own pc as a server at the moment.
for example:
On the client:
code: let Xcoordinate = askdata(myserver.com, Player1.XCoordinate)
On the Server:
code: server.onrequestdata(data){
if(data==Player1.Xcoordinate){
ReturnData(Player1.Xcoordinate)
};
};
This is just an example. But i wanted the code way to be something like that since the client's webpage is on their computer installed directly. For now I'm not really concerned about the security communication between the server and the client.
So my main question if it is possible? And what programming language can I use? At least compatible with Html or webpages.
I have been trying to search about some programming languages I can use but did not really find any in such way of code.
I found node.js and PHP but I did not find any code that happens to go with such way that I want to communicate the server and the client with.
Related
I'm trying to develop a web application in nodejs. I'm using an npm package called "simple-peer" but i don't think this issue is related to that. I was able to use this package and get it working when integrating it with a laravel application using an apache server as the back end. I could access the host machine through it's IP:PORT on the network and connect a separate client to the host successfully with a peer-to-peer connection. However, I'm now trying to develop this specifically in node without an apache back end. I have my express server up and running on port 3000, I can access the index page from a remote client on the same network through IP:3000. But when I try to connect through webrtc, I get a "Connection failed" error. If I connect two different browser instances on the same localhost device, the connection succeeds.
For reference: i'm just using the copy/pasted code from this usage demo. I have the "simplepeer.min.js" included and referenced in the correct directory.
So my main questions are: is there a setting or some webRTC protocol that could be blocking the remote clients from connecting? What would I need to change to meet this requirement? Why would it work in a laravel/webpack app with apache and not with express?
If your remote clients can not get icecandidates, you need TURN server.
When WebRTC Peer behind NAT, firewall or using Cellular Network(like smartphone), P2P Connection will fail.
At that time, for fallback, TURN server will work as a relay server.
I recommend coTURN.
Here is an simple implementation of simple-peer with nodejs backend for multi-user video/audio chat. You can find the client code in /public/js/main.js. Github Project and the Demo.
And just like #JinhoJang said. You do need a turn server to pass the information. Here is a list of public stun/turn servers.
I never done any API, I just recently become aware of REST, never used sockets or node.js, but I have this simple project in mind using all of these.
Imagine usual app with request/response stuff. Nothing fancy. But then sometimes I need real time functionality, lets say there's a live support for website, a chat. So majority of users never need sockets and everything is easy, but when they do, what's then? How that would look and work with restful api?
As you tag, socket.io is perfect for you. It creates a socket within the browser to your server without the user installing any third party program, using websockets and longpolling. And for the users that have old browsers and don't have those browser built-in functions, it can fallback to a third party plugin: Flash Player, but almost all browsers have it installed.
Is you are used to Javascript or object oriented programming, socket.io and node.js is a walk in the park. If you don't want to use node.js and socket.io, you can write your own implementation of client-server with this info:
WebSockets
Long Polling example
Flash AS3 Socket
As a small adition, simply you need your default web server (Apache, Nginx, Lighthttpd, whatever...) running in default port 80 and also running a node.js server in other port, let's say 8080. That second server will serve all the files needed to connect, because socket.io can only connect to the same domain and port that served the files (security reasons, I guess).
In short, you'll have 2 servers: One serving your entire webpage and another one serving the files needed to connect to your chat (and also serving the chat, obviously).
I have exactly that configuration made in one of my pages (a live sports streaming site) and to add the chat to my site I have this server running in port 8080 and I load it in the main page inside an iframe: http://www.example.com:8080/
As an adition, you can create a complete http server in node.js, but I don't guess that it is useful as a professional web server.
i wrote a simple C++ Server which is waiting for clients.
I want users to be able to connect to this client by opening a webpage without installing anything. So the only thing that comes to my mind is using Javascript. Since the server needs to react in realtime later on ( performance is an issue ) sending data with POST/GET is not wanted.
Is this possible with Node.js or Socket.io ? I am trying to find a good example but i only find node.js servers. And when i open a socket with
var socket = io.connect('localhost:25003');
it is sending weird data.
Does anyone have a simple example with a javascript client that can connect to anything and send raw data?
You cannot do plain TCP from browsers (unless you're writing a browser addon/extension or using something like a Java applet or a Flash bridge possibly). Socket.IO always uses HTTP. However those HTTP connections can then be upgraded to WebSockets or other protocols, depending on what the browser and/or Internet connection supports.
The "weird data" you're seeing is probably an HTTP message.
I have a program in an embedded device that outputs an xml string to a socket. The embedded device has lighthttpd has a web server. I want to use a web based client (no flash/silverlight) to connect to the socket and pull the xml data every second.
I looked at Node.js with Socket.io to get what I want to do, but I am not clear about how to proceed. Searching through the Node.js and Socket.io documentation and examples I see standard client-server behavior, nothing regarding what I am trying to do.
Basically, the web server is just there to accept a connection from a client on the socket that the embedded application is outputting data to. Basically the web server's purpose is to just let the client retrieve data from the raw tcp socket that the embedded application is writing to. Please advice.
I solved the problem using Websockify, which acts as bridge between a TCP Socket and a browser.
The html client will connect to a websocket, and Websockify will listen on the websocket port and transmit data between the websocket and the tcp socket.
Web browsers have the ability to do HTTP requests (which can be web page requests or Ajax requests for data) and webSocket connections. You will need to pick one of these two mechanisms if you're sticking with stock browser access.
If the lighthttpd web server in the embedded device does not support webSockets, then your choice will like be an Ajax call from the browser to your server. This is basically just an HTTP request that make return something different than a web page (often JSON data) and is designed to fetch data from the server into a web client.
If the lighthttpd web server does support webSockets, then you could use a webSocket connection to fetch the data too. This has an advantage of being a persistent connection and allows for the server to directly send data to the client (without the client even requesting more data) whenever it wants to (more efficient for constant updates).
An Ajax connection is generally not persistent. A client sends an Ajax request, the server returns the answer and the connection is closed. The next request starts a new Ajax request.
Either Ajax requests or webSocket connections should work just fine for your use. All browsers still in use support Ajax. WebSockets are supported in modern browsers (IE10 and higher).
Once you decide upon a client connection strategy, then you'd build your web app on the embedded device that served as the middleman between the browser and the data on the embedded device. It would collect the appropriate data from the embedded device and then be able to send that to browser clients that connected and requested the data.
I'm not sure exactly why you mentioned node.js. In this circumstance, it would be used as the web server and the environment for building your app and the logic that collects the data from your device and feeds it to the requesting web browser, but it sounds like you already have lighthttpd for this purpose. Personally, I recommend node.js if it works in your environment. Combined with socket.io (for webSocket support), it's a very nice way to connect browsers directly to an embedded device. I have an attic fan controller written in node.js and running on a Raspberry Pi. The node.js app monitors temperature probes and controls relays that switch attic fans and node.js also serves as a web server for me to administer and monitor the node.js. All-in-all, it's a pretty slick environment if you already know and like programming in Javascript and there's a rich set of add-in modules to extend its capabilities available through NPM. If, however, your embedded device isn't a common device that there is already support for node.js on or it doesn't already have node.js on it, then you'd be facing a porting tasks to make node.js run on it which might be more work than using some other development environment that already runs on the device like lighthttpd.
I basically want to know if its possible to use Socket.io using the server-side only with no client side? BUT I want to know if my server-side can instead connect with a different site that I cannot use Socket.io to connect to.
Use PhantomJS to load the third-party site and then inject your own javascript into the page to catch events and send those events back to your own server.
socket.io is a two-way connection. Client <--> Server. You must have a socket.io endpoint at both ends to even establish a connection in the first place. And, then once you establish the connection, you must have agreed upon messages that can be exchanged between the two ends for it to do anything useful.
It is not useful to have a server-side socket.io that doesn't actually connect to anything and nothing connects to it. It wouldn't be doing anything, just sitting there waiting for someone to connect to it.
It is possible to have two cooperating servers connect to one another with socket.io (one server just acts like a client in that case by initiating the connection to the other server). But, again both endpoints must participate in the connection for the connection to even be established and certainly for it to do anything useful.
If you just want to download the contents of a site for scraping purposes, then you would not use socket.io for that. You would just use the nodejs http module (or any of several other modules built on top of it). Your server would essentially pretend to be a browser. It would request a web page from any random web server using HTTP (not socket.io). That web server would return the web page via the normal HTTP request. Your receiving server can then do whatever it wants with that web page (scrape it, whatever).