I have been working with node.js for a while, now when I'm looking deeper into it, for a chat aplication instead of sending message as client - server - client, there must be some possible ways for direct client to client message sending?
Browsers tend to communicate with servers via HTTP. Some implement other protocols, like websockets & SPDY, but again, these are mostly client-server protocols.
Some plug-ins (like Flash & Java) can open ports and communicate client-client. (AFAIK, haven't actually used them.)
Chrome is the only browser I'm aware of that can (soon) open TCP and UDP sockets from Javascript and do direct client-client communication. At the moment normal web apps can't do this, your app needs to be run as a "Chrome Packaged App", with a special manifest file.
Here are the docs, a blog post describing the feature and a browserify module that can behave like the net node.js module in the browser.
EDIT: This should probably not be tagged as [node.js] since you're trying to run in browsers (not in your node vm), this is a Javascript / Browser question.
This is maybe out of date question, but take a look on PeerJS.
It requires server only as a connection manager (broker). But all communication is done between clients directly.
This does not have anything with server. If you need something like that and if clients are flash you can use RTMFP . For JS i google this library which is js bridge for RTMFP, I dont know how it works. At the end you can write you own library to chat beetween clients but this is much harder(IP addresses are behind NAT, etc...)
I think answer for your question is here
PS Also exist open-source in-browser server which written using JS, but I didn't google it quickly. If you find it, please notify me.
If you just don't want to write your own server you can use:
https://httprelay.io
Use AJAX calls to communicate between peers.
Related
We have an application which consumes a large amount of data. Currently a desktop app, but we would like to deliver it via the browser.
It doesn't make sense to me to create a web app where we need to transfer a ll the data used for the visualizations.
We're looking at RDP and some products out there that provide RDP access via a fully javascript client. They seem to work well with our app, but I've been thinking about what it would take to move off Windows.
Switching the front end so that it could run under Linux would not be trivial, but not impossible, so the main stumbling block would be delivery.
I was wondering if there are any X11 javascript servers out there, but have not found any leads.
Use xpra's builtin html5 client, it supports any application you can run on an X11 desktop.
You can use an HTML5 VNC viewer like https://github.com/kanaka/noVNC coupled with a VNC server like RealVNC
AFAIK, recent GTK has been ported to HTML5+Javascript in Gtk Broadway
And you could make your application a web application, for instance by using Wt, or by making it an HTTP server thru specialized HTTP server libraries like libonion, libmicrohttpd etc.
By using AJAX techniques (e.g. thru jquery) your application won't transmit all the display data to the browser at once (but only incrementally and only the actually shown data).
You might also consider fastcgi as a way to connect your application to some web server.
I know two, both at very infancy:
https://github.com/GothAck/javascript-x-server
and
https://github.com/ttaubert/x-server-js
Both need simple tcp-to-websockets proxy in front, but all X11 logic happen inside web page and all x11 objects exist and interact within browser (so it's not just remote framebuffer but real server)
You can ever run full Linux distribution in Web Browser, but that's require to run x86/ARM emulator and GNU/Linux inside it. It provides X server with possible web connection too.
For very simple applications you can use libgreattao toolkit and tao-network-client to connect to it. I'm the author of both project. The API isn't yet frozen, but it rather behaves stable. You can read about it here:
https://nintyfan.wordpress.com/2015/04/30/server-buildin-into-libgreattao-and-tao-network-client/
It can provide some problems with applications with a lot of data, because all elements must be send to client, when it were created, but instead we don't send full graphics(only icons is send) and user interface could be changed quickly. It also don't support mouse enter/leave/move events.
I must tell: do not download tarbar, but download version from svn.
Sounds like the easiest approach for you is to get xrdp, which is an RDP-server for X. Then you would use your RDP client to connect to it. I think Nomachine NX supports html directly now, but I'm not sure. There was talk of an html X2go-client, but I don't know anything about that either.
There is a server I need to talk to that publishes a protocol over TCP/IP for querying data from a database and listening on a socket to receive notifications when data is updated. The sever guys provide a Java API which uses this TCP protocol. This means I could easily write a Swing App to talk to this server.
I would like a browser based solution. As the protocol is known to me, could I do this in JavaScript? My app will have to display the data in a table. I have heard of Web Sockets but I'm not sure if it will allow this two way communication. Is it feasible? Is there a better way that is cross platform and will work in most browsers? Should I be considering a Java Swing based solution that runs inside a browser?
EDIT: What about changing the code in my C++ server to add an additional interface that my Javascript code can communicate directly with it?
The WebSocket protocol differs from TCP/IP sockets. You will have to write something to link them together.
You can do this perfectly well in JavaScript: use Node.js. There's enough tutorials to be found on the subject. The best way to link it to your in-browser JS is through Socket.IO.
Create a Node.js server that connects to the api
Make the server talk to your web app
Use it :)
This will work cross-platform and cross-browser (Socket.IO can use/emulate websockets even on IE6(!!)). You'll have to run a server-app (the Node.js app) though.
My personal opinion is that if you want a web/browser based solution, you should use native technology, and not Java.
Hope this helps :)
Sorry for the cryptic title, struggling to summarise my problem in a single line...
I wish to deploy an online, hosted website to serve a series of remote terminals which will be equipped with Chip & Pin payment card readers (aka pinpads). The pinpads are driven by some software on the PC within the terminal which is written by a 3rd party. The integration methods supported by this software are either text file based or socket based with a "request" and "response" workflow.
I have successfully carried out similar integrations in the past using client side VB Script to instantiate client side COM objects which communicate via socket connection with the local 3rd party software but this approach ties me to Windows and I would prefer to keep my options open.
My web server will be Ruby On Rails based and I intend to use HTML5 and CSS3 to provide a rich experience on the payment terminals and wondered if I can use web sockets for client side communications? From what I understand, this is not what they are designed for and so I think the answer is no.
So, what are my options? Can i use client side JavaScript to carry out socket communications or is this prevented by browser security measures? From the browser's perspective it would be communicating with a specific numbered port on "localhost"
If socket comms is not possible, can I use JavaScript to create client side text files to integrate that way?
Or am I stuck with VB script and local COM objects?
Any suggestions would be most welcome and please let me know if you need clarification on any aspect of my question.
Kind regards,
Craig.
I don't think you can write a text file with JavaScript. And you can't put arbitrary bytes on a socket either. I don't completely understand you scenario. It sounds like you have Ruby sunning on a server and JavaScript and this third party pinpad thing running on a client. And you need the two client entities to be able to talk to each other. Could you have the browser communicate with your Ruby server (using one of many web technologies) and then have your Ruby server relay the data back to the pinpad socket. Or is the pinpad only a local socket?
The only type of socket-based connection you are allowed to open on a standard web page that runs javascript is an HTTP socket. You'll have a lot more freedom to use sockets if you develop a browser plugin, which is written in javascript. Firefox, I know, supports sockets in extensions.
https://developer.mozilla.org/en/XPCOM_Interface_Reference/nsISocketProvider
We have a network camera. It has an HTTP server to provides the current image. There is also a Telnet interface for controlling the camera (i.e. trigger, focus, etc.). I would like to add an HTML page to the camera that would provide a simple interface (we already have client software we write). I can "GET" the image and display that, but I would also like to have controls that use the Telnet interface to control the camera. So a button might have JavaScript code behind it that connects to the camera via Telnet (logs in) and issues the command to trigger the camera.
I know that JavaScript/browsers support connecting to the same host via XMLHttpRequest. In this case I would be looking to open a socket on port 23 and send text. I also know that I can do this through Flash, Java, or some other technology, but I would prefer to use JavaScript only. If that is possible.
Thomaschaaf is correct, while HTML5 introduces websockets you'll find they still require special server support as they post HTTP style information upon opening the socket:
JS/HTML5 WebSocket: Connect without HTTP call
The best way, currently, to have true sockets is to either
use a flash or Java component on the webpage that does the actual socket work.
use a proxy server with websockets that can handle the additional protocol overhead of websockets and connect to the real tcp/ip port with plain sockets.
The jsterm example Matt linked does the latter, and if your webcans are behind a firewall it will not work in your situation without also implementing another server.
There are libraries that implement the first method, two are linked here for convenience, many others can be found using a search engine:
http://stephengware.com/proj/javasocketbridge/ (Java)
http://matthaynes.net/blog/2008/07/17/socketbridge-flash-javascript-socket-bridge/ (Flash)
jsTerm is an HTML5 implementation of a Telnet client.
You'll need a browser that supports HTML5 WebSockets. WebSockets is the only method of doing non-HTTP requests with pure JavaScript.
Currently there is no way to do socket connections with JavaScript only.
But what you are searching for is a socket connection ;)
https://developer.mozilla.org/en/XML_Extras
If I interpret the question liberally as "is there a remote connectivity library for Javascript", then the answer is yes (quoting from https://xtermjs.org/):
A web based SSH2 client using xterm.js, socket.io, and ssh2: https://github.com/billchurch/WebSSH2
HTML5 Based SSHv2 Web Client with E2E encryption utilising xterm.js, SJCL & websockets: https://github.com/stuicey/SSHy
I've tried WebSSH2 with node.js briefly, it worked for me - I managed to connect to a Linux-based server with it.
(I know this probably doesn't help the OP but this is a 7-year old question anyway. Maybe it helps others who are needing an answer to a similar problem.)
Introduction: I want to develop the chat client that user can chat on the browser and I use the protocol call xmpp. Because of HTML5 web socket not yet available I try flash xmlsocket instead.
Problem: I cannot connect to the server via browser. I'm not sure why, but I think that it is the problem of the server configuration.
Question: Which is the best jabber server suitable for this job?
Most probably this is a permission issue. Either that or you've just configured the wrong host/port to connect to. Flash is not allowed to connect to other hosts than the one it was gotten from itself. You have to explicitely allow flash connections on the receiving side of the request (so on the chat server that you are connecting to). Google for crossdomain.xml to get more info.
ejabberd sounds like a suitable option for you. ejabberd is xmpp server written in erlang and is used quite widely. Many of the well known web based im services like www.meebo.com etc are known to be running on ejabberd. It allows you to install other transports which would let you enable talking to users of other protocol like yahoo, msn, icq etc.
You can also have a look at the xiff action script library by ignite realtime. It is an xmpp client library in action script. If you use this library you would just need to implement the ui components.
Hum... flash is ok, but you'd be better of using something like BOSH, which is basically an HTTP layer over XMPP.
Ejabberd would be a good server, as it supports BOSH, I don't know about OpenFire or Tigase (but I'd say they do). Other servers should be looked at carefully because they don't seem to have a "dynamic" community.
You will need a lot of Javascript, and for that, I can recommend StropheJS, which is probably the very best library out there today.
We have created a MUC (Multi-user chat room) client called Aristochat that works in the browser recently at Superfeedr. You can find the code on Github and an example here.