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Introducing WebSockets: Bringing Sockets to the Web

Introducing WebSockets: Bringing Sockets to the Web
The Problem: Low Latency Client-Server and Server-Client Connections The web has been largely built around the so-called request/response paradigm of HTTP. A client loads up a web page and then nothing happens until the user clicks onto the next page. Around 2005, AJAX started to make the web feel more dynamic. Still, all HTTP communication was steered by the client, which required user interaction or periodic polling to load new data from the server. However, all of these work-arounds share one problem: They carry the overhead of HTTP, which doesn't make them well suited for low latency applications. Introducing WebSocket: Bringing Sockets to the Web The WebSocket specification defines an API establishing "socket" connections between a web browser and a server. Getting Started You open up a WebSocket connection simply by calling the WebSocket constructor: var connection = new WebSocket(' ['soap', 'xmpp']); Notice the ws:. Communicating with the Server Related:

BeagleBone – Bone BrewsBeagleBone Archives - Bone Brews In a previous tutorial, we covered how to connect and read from DS18B20 sensors with your Beaglebone. I’d now like to cover the process of displaying live-updating DS18B20 temperatures in your browser using a Beaglebone Black. We’ll be using Socket.IO, a simple library that can be used to quickly communicate between a web browser and the server using the web sockets protocol. This tutorial will display all connected DS18B20 sensors in a nicely formatted table. This is geared towards developing a basic understanding how to use nodeJS with Socket.IO and the DS18B20 sensor. It can be used as a groundwork to use temperature readings in graphs and other formats. Prerequisites I will assume you already have the following installed: The Beaglebone and Raspberry Pi nodeJS development community is quite active. Install NodeJS Packages In a SSH session, move the current directory to your webserver’s document root (i.e .e /var/www) and install the necessary Node packages. Create app.js index.html <!

Node.js Websocket Examples with What are Websockets? Over the past few years, a new type of communication started to emerge on the web and in mobile apps, called websockets. This protocol has been long-awaited and was finally standardized by the IETF in 2011, paving the way for widespread use. This new protocol opens up a much faster and more efficient line of communication to the client. Like HTTP, websockets run on top of a TCP connection, but they're much faster because we don't have to open a new connection for each time we want to send a message since the connection is kept alive for as long as the server or client wants. Even better, since the connection never dies we finally have full-duplex communication available to us, meaning we can push data to the client instead of having to wait for them to ask for data from the server. How do Websockets Work? The server then sends back an HTTP 101 "Switching Protocols" response, acknowledging that the connection is going to be upgraded. Some Websocket Examples Server Client

buildar/getting_started_with_webrtc Plug an HTML5 Photo Editor Into Your Site With Aviary Feather The WebSocket API Abstract This specification defines an API that enables Web pages to use the WebSocket protocol (defined by the IETF) for two-way communication with a remote host. Status of This document This section describes the status of this document at the time of its publication. Other documents may supersede this document. A list of current W3C publications and the most recently formally published revision of this technical report can be found in the W3C technical reports index at If you wish to make comments regarding this document, you can enter feedback using this form: You can also e-mail feedback to (subscribe, archives), or (subscribe, archives). Implementors should be aware that this specification is not stable. The latest stable version of the editor's draft of this specification is always available on the W3C CVS server and in the WHATWG Subversion repository. E-mail notifications of changes Table of Contents 1 Introduction WebIDL

Apache and Node.js on the Same Server Chat App Best Practice Guide with JavaScript APIs | PubNub One of the most common use-cases of PubNub data stream network is for chatting. It can be a standalone chat app, or a chat feature in a larger application or website. A good example of latter is the one seen on Twitter Periscope, where viewers can interact with the videocaster during a live video stream. Simulated image from an screenshot from Periscope by Monterey Bay Aquarium We work hard to make it easy for you to build your own apps, however, nothing is too easy- we get questions from many of you every day. Especially, PubNub’s support superstars, Craig, Fred, and Eric are wrangling tough questions nearly 24/7! So I picked up the common features that used in chat apps, and wrote up a use-cases based best practice guide. Speaking of encrypted chat apps, you may have heard the recent news about WhatsApp started encrypting all messages for their 1 billion users. So if you are building chat apps, or apps that comes with a chat feature, read on!

A Web RTC Tutorial With WebRTC, adding a peer-to-peer video chat to a site is as easy as child's play and the best part of it is that there is no need for your users to download plugins to use the service. There are two pieces needed to set up peer-to-peer video chat using WebRTC: an HTML5 compliant browser, and the proper code on your server. This blog will walk you through the steps to get a simple service up and running. WebRTC is part of the HTML5 standard and is still under development. But by downloading an augmented WebKit library from Ericsson Labs, you can try it out today. At present, only Ubuntu 11.04 is supported for the browser, but there are no such restrictions on the server. Installing the Browser To install the browser, follow the steps here. /usr/lib/webkitgtk-1.0-0/libexec/GtkLauncher Note that the following steps are only required if you want to host the signaling server yourself. Setting up the Server Then, install libevent: before the install step: <! Step 1

20 Things I Learned About Browsers and the Web How HTML5 Web Sockets Interact With Proxy Servers With the recent explosion of WebSocket server implementations, a lot of questions have come up about how HTML5 Web Sockets deal with proxy servers, firewalls, and load-balancing routers. Will proxy servers automatically kill WebSocket connections? Do HTML5 Web Sockets handle firewalls and proxy server issues better than Comet? Are Web Sockets the silver bullet in seamless proxy server traversal? About HTML5 Web Sockets and Proxy Servers Let's start with some basic concepts: what exactly are HTML5 Web Sockets and proxy servers? HTML5 Web Sockets The HTML5 Web Sockets specification defines the Web Sockets API that enables web pages to use the Web Socket protocol for full-duplex communication with a remote host. To use HTML5 Web Sockets to connect from a Web client to a remote end-point, you create a new WebSocket instance and provide it with the URL that represents the end-point to which you want to connect. Proxy Servers HTML5 Web Sockets and Proxy Servers The WebSocket Upgrade Let's recap.