To start with **Socket.IO** I suggest you read first the example on the main page:

http://socket.io/

On the **server side**, read the &quot;How to use&quot; on the GitHub source page:

https://github.com/Automattic/socket.io

And on the **client side**:

https://github.com/Automattic/socket.io-client

Finally you need to read this great tutorial:

http://howtonode.org/websockets-socketio

*Hint*: At the end of this blog post, you will have some links pointing on source code that could be some help.

A &#39;fun&#39; way to learn socket.io is to play BrowserQuest by mozilla and look at its source code :-)

http://browserquest.mozilla.org/

https://github.com/mozilla/BrowserQuest

I found these two links very helpful while I was trying to learn socket.io:

* http://fzysqr.com/2011/02/28/nodechat-js-using-node-js-backbone-js-socket-io-and-redis-to-make-a-real-time-chat-app/
* &lt;strike&gt; http://thecoffman.com/2011/02/21/getting-your-feet-wet-with-node.js-and-socket.io/
&lt;/strike&gt;

Using `$(&#39;html&#39;).html()` I can get the HTML within the `&lt;html&gt;` tag (`&lt;head&gt;`, `&lt;body&gt;`, etc.). But how can I get the actual HTML of the `&lt;html&gt;` tag (with attributes)?

Alternatively, is it possible to get the entire HTML of the page (including doctype, `&lt;html&gt;`, etc.) with jQuery (or plain old JavaScript)?


How to get the &lt;html&gt; tag HTML with JavaScript / jQuery?

I have two text files, each of them contains an information by line such like that

    file1.txt            file2.txt
    ----------           ---------
    linef11              linef21
    linef12              linef22
    linef13              linef23
     .                    .
     .                    .
     .                    .

I would like to merge theses files lines by lines using a bash script in order to obtain:

    fileresult.txt
    --------------
    linef11     linef21
    linef12     linef22
    linef13     linef23
     .           .
     .           .
     .           .

How can this be done in Bash?

How to merge two files line by line in Bash

I am very new to the world of webdevelopment and jumped into the bandwagon because I find the concept of HTML5 very interesting. I am fairly confident on working with canvas and would now like to move over to websockets part of it. I have come to understand socket.io is by far the framework to work with, when we want to work with web sockets.

Any pointers on what tutorial and examples to refer to for a total dummy would be very appreciated!

Good beginners tutorial to socket.io?

<p>I am very new to the world of webdevelopment and jumped into the bandwagon because I find the concept of HTML5 very interesting. I am fairly confident on working with canvas and would now like to move over to websockets part of it. I have come to understand socket.io is by far the framework to work with, when we want to work with web sockets.</p>
<p>Any pointers on what tutorial and examples to refer to for a total dummy would be very appreciated!</p>


How can I get and set the current web page scroll position?

I have a long form which needs to be refreshed based on user actions/input.  When this happens, the page resets to the very top, which is annoying to the users, because they have to scroll back down to the point they were at.

If I could capture the current scroll position (in a hidden input) before the page reloads, I could then set it back after it reloads.

How to get and set the current web page scroll position?

I have no idea how to do this? I&#39;m adding comma numbers, result is of course always a number with way too many digits after the comma. anyone?

Rounding numbers to 2 digits after comma

Based on the question [jQuery code not working in IE](https://stackoverflow.com/q/4100872), `text/javascript` is used in HTML documents so Internet Explorer can understand it.

But I’m wondering, when would you use `application/javascript`, and more importantly, why would you use it instead of `text/javascript`?

When to use the JavaScript MIME type application/javascript instead of text/javascript?

In the javascript dom  - what is the difference between offsetHeight and clientHeight of an element?

difference between offsetHeight and clientHeight

I&#39;m using the hash to load content dynamically. To make the back button work I am capturing hash changes. However sometimes I need to change the hash without triggering the hash changed function (eg, when the page was redirected server side and I need to update the hash once the content has returned.)

The best solution I have come up with is to unbind the hashchange event, make the change and then rebind it. However, as this happens asynchronously, I am finding that it rebinds too quickly and still catches the hash change.

My solution at the moment is very poor: Rebinding in a setTimeout. Does anyone have a better idea?


        $(window).unbind( &#39;hashchange&#39;, hashChanged);
        window.location.hash  = &quot;!&quot; + url;
        setTimeout(function(){
            $(window).bind( &#39;hashchange&#39;, hashChanged);
        }, 100);
&lt;br&gt;

Edit:&lt;br&gt;
Amir Raminfar&#39;s suggestion prompted me to a solution that does not require a timeout.
I added a class variable

    _ignoreHashChange = false;

When I want to change the hash silently I do this:

    _ignoreHashChange = true;
    window.location.hash  = &quot;!&quot; + url;

and the hash changed event does this :

    function hashChanged(event){
        if(_ignoreHashChange === false){
            url = window.location.hash.slice(2);
            fetchContent(url);
        }
        _ignoreHashChange = false;
    }



Change hash without triggering a hashchange event

I recently started programming my first node.js. However, I discovered that I am unable to create a contact me form that sends straight to my email since I can&#39;t find any modules from node that is able to send emails.

Does anyone know of a node.js email library or an sample contact form script?

Sending emails in Node.js?

I know that global variables are bad.

But if I am using node&#39;s module &quot;util&quot; in 40 files in my framework, isn&#39;t it better to just declare it as a global variable like:

    util = require(&#39;util&#39;);

in the index.js file instead of writing that line in 40 files?

Cause I often use the same 5-10 modules in each file, that would save a lot of time instead of copy paste all the time.

Isn&#39;t DRY good in this case?

Global variables for node.js standard modules?

I&#39;m trying to write a test for the [Jasmine Test Framework][1] which expects an error. At the moment I&#39;m using a [Jasmine Node.js integration from GitHub][2].

In my Node.js module I have the following code:

    throw new Error(&quot;Parsing is not possible&quot;);

Now I try to write a test which expects this error:

    describe(&#39;my suite...&#39;, function() {
        [..]
        it(&#39;should not parse foo&#39;, function() {
        [..]
            expect(parser.parse(raw)).toThrow(new Error(&quot;Parsing is not possible&quot;));
        });
    });

I tried also `Error()` and some other variants and just can&#39;t figure out how to make it work.

  [1]: http://jasmine.github.io/
  [2]: https://github.com/sconover/jasmine-node





How can I write a test which expects an &#39;Error&#39; to be thrown in Jasmine?

I am working on a websocket oriented node.js server using Socket.IO. I noticed a bug where certain browsers aren&#39;t following the correct connect procedure to the server, and the code isn&#39;t written to gracefully handle it, and in short, it calls a method to an object that was never set up, thus killing the server due to an error.

My concern isn&#39;t with the bug in particular, but the fact that when such errors occur, the entire server goes down. Is there anything I can do on a global level in node to make it so if an error occurs it will simply log a message, perhaps kill the event, but the server process will keep on running?

I don&#39;t want other users&#39; connections to go down due to one clever user exploiting an uncaught error in a large included codebase.

Make node.js not exit on error

I have a script I am requiring from a Node.js script, which I want to keep JavaScript engine independent.

For example, I want to do `exports.x = y;` only if it’s running under Node.js. How can I perform this test?

---

When posting this question, I didn’t know the Node.js modules feature is based on [CommonJS][1].

For the specific example I gave, a more accurate question would’ve been:

How can a script tell whether it has been required as a CommonJS module?


  [1]: http://www.commonjs.org/

How to check whether a script is running under Node.js?

Can an ordered list produce results that looks like 1.1, 1.2, 1.3 (instead of just 1, 2, 3, ...) with CSS? So far, using `list-style-type:decimal` has produced only 1, 2, 3,  not 1.1, 1.2., 1.3.

Can ordered list produce result that looks like 1.1, 1.2, 1.3 (instead of just 1, 2, 3, ...) with css?

When I&#39;m debugging a site, sometimes the hovered selectors are a little long winded and similar to other ones, is there a way to apply a kind of &quot;sticky&quot; state to hover rules in Firebug? 

Example; I hover over a nav bar and want to copy the selector out of firebug to search in the CSS, but as soon as I move my mouse, the selector (obviously) disappears as the nav `&lt;li&gt;` isn&#39;t hovered anymore.

Any way to do this?

Thanks :)

Can you make hovered state in Firebug &quot;sticky?&quot;

I&#39;d like to update element&#39;s text dynamically:

```html
&lt;div&gt;
   **text to change**
   &lt;someChild&gt;
	   text that should not change
   &lt;/someChild&gt;
   &lt;someChild&gt;
	   text that should not change
   &lt;/someChild&gt;
&lt;/div&gt;
```

I&#39;m new to jQuery, so this task seems to be quite challenging for me.
Could someone point me to a function/selector to use?

If it is possible, I&#39;d like to do it without adding a new container for the text I need to change.

How can I change an element&#39;s text without changing its child elements?

I have a &lt;code&gt;div&lt;/code&gt; container on my web page with fixed width and it contains form elements for logging in. Below these elements there are a submit button, forgotten password link etc.

It happens the last line elements need fewer width than the box provides. How to spread them evenly? I don&#39;t want

 - default
&lt;pre&gt;
| A B C           |
&lt;/pre&gt;

 - centering the line like
&lt;pre&gt;
|      A B C      |
&lt;/pre&gt;

 - nor table layout
&lt;pre&gt;
|  A  |  B  |  C  |
&lt;/pre&gt;


&lt;br/&gt;Instead I am looking for some CSS way to achieve:
&lt;pre&gt;
|  A    B    C  |
&lt;/pre&gt;

That is:

 - put about equal space between all elements
 - center the whole thing to avoid the first or last  to the side


**edit:**
[This answer][1] worked best. I created templates for 2 or 3 elements like this:

&lt;pre&gt;
div.spread2evenly &gt; div {
    display: inline-block;
    *display: inline; /* For IE7 */
    zoom: 1; /* Trigger hasLayout */
    width: 50%;
    text-align: center;
}
&lt;/pre&gt;


  [1]: https://stackoverflow.com/questions/4108726/how-to-spread-html-evenly-over-a-line/4108814#4108814

How to spread elements horizontally evenly?

To clarify when I ask about browser to browser communication I mean without a server in between forwarding message.  I would like to implement something like this for a game.  If p2p in websockets isn&#39;t possible are there similar alternatives?  Any help is appreciated.  

Do websockets allow for p2p (browser to browser) communication?

What is the fastest way to stream *live* video using JavaScript? Is WebSockets over TCP a fast enough protocol to stream a video of, say, 30fps?

Video streaming over websockets using JavaScript

Using HTML5 Websockets, can I open a socket directly between 2 clients (browsers) (assuming I know their IP addresses and there are no NAT traversal issues). I want to send some data directly from one browser to another browser, essentially creating a P2P network. Everything I&#39;ve read so far on the web, websockets are all used to communicate between client and server, but nothing about client to client.


Can HTML5 Websockets connect 2 clients (browsers) directly without using a server? (P2P)

Looks like it&#39;s easy to add custom HTTP headers to your websocket client with any HTTP header client which supports this, but I can&#39;t find how to do it with the web platform&#39;s `WebSocket` API. 

Anyone has a clue on how to achieve it? 

    var ws = new WebSocket(&quot;ws://example.com/service&quot;);

Specifically, I need to be able to send an HTTP Authorization header.

HTTP headers in Websockets client API

I&#39;d like to know if it&#39;s possible to broadcast on different websocket &quot;connections&quot; running from the same &lt;a href=&quot;https://github.com/miksago/node-websocket-server&quot;&gt;node-websocket-server&lt;/a&gt; app instance. Imagine a chatroom server with multiple rooms, only broadcasting messages to the participants specific to each room, on a single node.js server process. I&#39;ve successfully implemented a one-chatroom-per-process solution, but I want to take it to the next level.

node-websocket-server: possible to have multiple, separate &quot;broadcasts&quot; for a single node.js process?

I&#39;m using express framework. I want to reach session data from socket.io. I tried express dynamicHelpers with client.listener.server.dynamicViewHelpers data, but i can&#39;t get session data. Is there a simple way to do this? Please see the code

    app.listen(3000);
    
    var io = require(&#39;socket.io&#39;);
    var io = io.listen(app);
    
    io.on(&#39;connection&#39;, function(client){
        // I want to use session data here
    	client.on(&#39;message&#39;, function(message){
            // or here
    	});
    	client.on(&#39;disconnect&#39;, function(){
            // or here
    	}); 
    });



socket.io and session?

I&#39;m working with socket.io and node.js and until now it seems pretty good, but I don&#39;t know how to send a message from the server to an specific client, something like this:

    client.send(message, receiverSessionId)

But neither the `.send()` nor the `.broadcast()` methods seem to supply my need.

What I have found as a possible solution, is that the `.broadcast()` method accepts as a second parameter an array of SessionIds to which not send the message, so I could pass an array with all the SessionIds connected at that moment to the server, except the one I wish send the message, but I feel there must be a better solution.

Any ideas?

Send message to specific client with socket.io and node.js

How to best send additional data upon socket connection?

Client:

    socket.on(&#39;connect&#39;,function(){ 
    //I&#39;d like set some values and pass them up to the node server.
    });

Node.js Server:

    io.on(&#39;connection&#39;, function(client){
    //I&#39;d like to get the data here.
    });

For example sending a user name or email address etc.

Send additional data on socket connection

I am trying to use Socket.IO in Node.js, and am trying to allow the server to give an identity to each of the Socket.IO clients.  As the socket code is outside the scope of the http server code, it doesn&#39;t have easy access to the request information sent, so I&#39;m assuming it will need to be sent up during the connection.  What is the best way to

1) get the information to the server about who is connecting via Socket.IO

2) authenticate who they say they are (I&#39;m currently using Express, if that makes things any easier)

Socket.IO Authentication

[Socket.IO][1] seems to be the most popular and active WebSocket emulation library. [Juggernaut][2] uses it to create a complete pub/sub system.

[Faye][3] is also popular and active, and has its own javascript library, making its complete functionality comparable to Juggernaut. Juggernaut uses node for its server, and Faye can use either node or rack. Juggernaut uses Redis for persistence (**correction:** it uses Redis for pub/sub), and Faye only keeps state in memory.

1. Is everything above accurate?
2. Faye says it implements [Bayeux][4] -- i think Juggernaut does not do this -- is that because Juggernaut is lower level (IE, I can implement Bayeux using Juggernaut)
3. Could Faye switch to using the Socket.IO browser javascript library if it wanted to? Or do their javascript libraries do fundamentally different things?
4. Are there any other architectural/design/philosophy differences between the projects?


  [1]: http://socket.io/
  [2]: https://github.com/maccman/juggernaut
  [3]: http://faye.jcoglan.com/
  [4]: http://svn.cometd.com/trunk/bayeux/bayeux.html

Content Type	Original Author	Original Content on Stackoverflow
Question	Shouvik	View Question on Stackoverflow
Solution 1 - Javascript	FR6	View Answer on Stackoverflow
Solution 2 - Javascript	250R	View Answer on Stackoverflow
Solution 3 - Javascript	Liam	View Answer on Stackoverflow

Good beginners tutorial to socket.io?

Javascript Problem Overview

Javascript Solutions

Solution 1 - Javascript

Solution 2 - Javascript

Solution 3 - Javascript

How to merge two files line by line in Bash

How to get the <html> tag HTML with JavaScript / jQuery?

Attributions